diff --git a/benches/Cargo.toml b/benches/Cargo.toml
index c5014f5a..57a1c9d4 100644
--- a/benches/Cargo.toml
+++ b/benches/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "juniper_benchmarks"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 authors = ["Christoph Herzog <chris@theduke.at>"]
 publish = false
 
diff --git a/benches/benches/benchmark.rs b/benches/benches/benchmark.rs
index 7aa5da65..c2ba501c 100644
--- a/benches/benches/benchmark.rs
+++ b/benches/benches/benchmark.rs
@@ -38,7 +38,7 @@ fn bench_sync_vs_async_users_flat_instant(c: &mut Criterion) {
                 b.iter(|| {
                     j::execute_sync(
                         SYNC_QUERY,
-                        vec![("ids".to_string(), ids.clone())].into_iter().collect(),
+                        vec![("ids".to_owned(), ids.clone())].into_iter().collect(),
                     )
                 })
             },
@@ -58,7 +58,7 @@ fn bench_sync_vs_async_users_flat_instant(c: &mut Criterion) {
             b.iter(|| {
                 let f = j::execute(
                     ASYNC_QUERY,
-                    vec![("ids".to_string(), ids.clone())].into_iter().collect(),
+                    vec![("ids".to_owned(), ids.clone())].into_iter().collect(),
                 );
                 rt.block_on(f)
             })
@@ -77,7 +77,7 @@ fn bench_sync_vs_async_users_flat_instant(c: &mut Criterion) {
             b.iter(|| {
                 let f = j::execute(
                     ASYNC_QUERY,
-                    vec![("ids".to_string(), ids.clone())].into_iter().collect(),
+                    vec![("ids".to_owned(), ids.clone())].into_iter().collect(),
                 );
                 rt.block_on(f)
             })
diff --git a/benches/src/lib.rs b/benches/src/lib.rs
index 526d0043..c8ad5b51 100644
--- a/benches/src/lib.rs
+++ b/benches/src/lib.rs
@@ -11,11 +11,11 @@ pub type QueryResult = Result<
     String,
 >;
 
-pub struct Context {}
+pub struct Context;
 
 impl Context {
     fn new() -> Self {
-        Self {}
+        Self
     }
 }
 
@@ -51,8 +51,8 @@ impl User {
         Self {
             id,
             kind: UserKind::Admin,
-            username: "userx".to_string(),
-            email: "userx@domain.com".to_string(),
+            username: "userx".into(),
+            email: "userx@domain.com".into(),
             gender: Some(Gender::Female),
         }
     }
@@ -97,7 +97,7 @@ pub fn new_schema() -> RootNode<'static, Query, EmptyMutation<Context>, EmptySub
 pub fn execute_sync(query: &str, vars: Variables) -> QueryResult {
     let root = new_schema();
     let ctx = Context::new();
-    juniper::execute_sync(query, None, &root, &vars, &ctx).map_err(|e| format!("{:?}", e))
+    juniper::execute_sync(query, None, &root, &vars, &ctx).map_err(|e| format!("{e:?}"))
 }
 
 pub async fn execute(query: &str, vars: Variables) -> QueryResult {
@@ -105,5 +105,5 @@ pub async fn execute(query: &str, vars: Variables) -> QueryResult {
     let ctx = Context::new();
     juniper::execute(query, None, &root, &vars, &ctx)
         .await
-        .map_err(|e| format!("{:?}", e))
+        .map_err(|e| format!("{e:?}"))
 }
diff --git a/book/book.toml b/book/book.toml
index 9fc67124..9dad3932 100644
--- a/book/book.toml
+++ b/book/book.toml
@@ -13,4 +13,4 @@ create-missing = false
 git_repository_url = "https://github.com/graphql-rs/juniper"
 
 [rust]
-edition = "2018"
+edition = "2021"
diff --git a/book/src/advanced/dataloaders.md b/book/src/advanced/dataloaders.md
index 560f6048..ef03afc1 100644
--- a/book/src/advanced/dataloaders.md
+++ b/book/src/advanced/dataloaders.md
@@ -68,7 +68,7 @@ use std::env;
 
 pub fn get_db_conn() -> Connection {
     let pg_connection_string = env::var("DATABASE_URI").expect("need a db uri");
-    println!("Connecting to {}", pg_connection_string);
+    println!("Connecting to {pg_connection_string}");
     let conn = Connection::connect(&pg_connection_string[..], TlsMode::None).unwrap();
     println!("Connection is fine");
     conn
@@ -101,7 +101,7 @@ impl BatchFn<i32, Cult> for CultBatcher {
 
     // A hashmap is used, as we need to return an array which maps each original key to a Cult.
     async fn load(&self, keys: &[i32]) -> HashMap<i32, Cult> {
-        println!("load cult batch {:?}", keys);
+        println!("load cult batch {keys:?}");
         let mut cult_hashmap = HashMap::new();
         get_cult_by_ids(&mut cult_hashmap, keys.to_vec());
         cult_hashmap
diff --git a/book/src/advanced/introspection.md b/book/src/advanced/introspection.md
index 3fabcb73..d7bc7c2f 100644
--- a/book/src/advanced/introspection.md
+++ b/book/src/advanced/introspection.md
@@ -66,7 +66,7 @@ type Schema = juniper::RootNode<
 
 fn main() {
     // Create a context object.
-    let ctx = Context{};
+    let ctx = Context;
 
     // Run the built-in introspection query.
     let (res, _errors) = juniper::introspect(
diff --git a/book/src/advanced/subscriptions.md b/book/src/advanced/subscriptions.md
index 90877c42..89ce7bf4 100644
--- a/book/src/advanced/subscriptions.md
+++ b/book/src/advanced/subscriptions.md
@@ -98,7 +98,7 @@ where [`Connection`][Connection] is a `Stream` of values returned by the operati
 # 
 # impl Database {
 #     fn new() -> Self {
-#         Self {}
+#         Self
 #     }
 # }
 # 
@@ -126,7 +126,7 @@ where [`Connection`][Connection] is a `Stream` of values returned by the operati
 type Schema = RootNode<'static, Query, EmptyMutation<Database>, Subscription>;
 
 fn schema() -> Schema {
-    Schema::new(Query {}, EmptyMutation::new(), Subscription {})
+    Schema::new(Query, EmptyMutation::new(), Subscription)
 }
 
 async fn run_subscription() {
diff --git a/book/src/quickstart.md b/book/src/quickstart.md
index b8ff7226..770b86a6 100644
--- a/book/src/quickstart.md
+++ b/book/src/quickstart.md
@@ -130,7 +130,7 @@ impl Mutation {
 type Schema = juniper::RootNode<'static, Query, Mutation, EmptySubscription<Context>>;
 #
 # fn main() {
-#   let _ = Schema::new(Query, Mutation{}, EmptySubscription::new());
+#   let _ = Schema::new(Query, Mutation, EmptySubscription::new());
 # }
 ```
 
diff --git a/book/src/servers/iron.md b/book/src/servers/iron.md
index 9c81fc4b..38782c36 100644
--- a/book/src/servers/iron.md
+++ b/book/src/servers/iron.md
@@ -50,7 +50,7 @@ struct Root;
 #[juniper::graphql_object]
 impl Root {
     fn foo() -> String {
-        "Bar".to_owned()
+        "Bar".into()
     }
 }
 
diff --git a/book/src/types/interfaces.md b/book/src/types/interfaces.md
index 6a394ceb..87b72348 100644
--- a/book/src/types/interfaces.md
+++ b/book/src/types/interfaces.md
@@ -227,7 +227,7 @@ impl ObjA {
 //     ^^ the evaluated program panicked at 
 //        'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` 
 //         isn't present on the interface and so has to be nullable.'        
-        is_present.then(|| self.id.as_str()).unwrap_or("missing")
+        is_present.then_some(&self.id).unwrap_or("missing")
     }
 }
 
diff --git a/book/src/types/objects/complex_fields.md b/book/src/types/objects/complex_fields.md
index 86d310ec..f8aa1399 100644
--- a/book/src/types/objects/complex_fields.md
+++ b/book/src/types/objects/complex_fields.md
@@ -157,7 +157,7 @@ They can have custom descriptions and default values.
 # extern crate juniper;
 # use juniper::graphql_object;
 #
-struct Person {}
+struct Person;
 
 #[graphql_object]
 impl Person {
@@ -177,7 +177,7 @@ impl Person {
         #[graphql(default)]
         arg2: i32,
     ) -> String {
-        format!("{} {}", arg1, arg2)
+        format!("{arg1} {arg2}")
     }
 }
 #
diff --git a/book/src/types/objects/error_handling.md b/book/src/types/objects/error_handling.md
index 1d4d8247..5404c4bf 100644
--- a/book/src/types/objects/error_handling.md
+++ b/book/src/types/objects/error_handling.md
@@ -242,15 +242,15 @@ impl Mutation {
 
         if !(10 <= name.len() && name.len() <= 100) {
             errors.push(ValidationError {
-                field: "name".to_string(),
-                message: "between 10 and 100".to_string()
+                field: "name".into(),
+                message: "between 10 and 100".into(),
             });
         }
 
         if !(1 <= quantity && quantity <= 10) {
             errors.push(ValidationError {
-                field: "quantity".to_string(),
-                message: "between 1 and 10".to_string()
+                field: "quantity".into(),
+                message: "between 1 and 10".into(),
             });
         }
 
@@ -338,11 +338,11 @@ impl Mutation {
         };
 
         if !(10 <= name.len() && name.len() <= 100) {
-            error.name = Some("between 10 and 100".to_string());
+            error.name = Some("between 10 and 100".into());
         }
 
         if !(1 <= quantity && quantity <= 10) {
-            error.quantity = Some("between 1 and 10".to_string());
+            error.quantity = Some("between 1 and 10".into());
         }
 
         if error.name.is_none() && error.quantity.is_none() {
@@ -436,11 +436,11 @@ impl Mutation {
         };
 
         if !(10 <= name.len() && name.len() <= 100) {
-            error.name = Some("between 10 and 100".to_string());
+            error.name = Some("between 10 and 100".into());
         }
 
         if !(1 <= quantity && quantity <= 10) {
-            error.quantity = Some("between 1 and 10".to_string());
+            error.quantity = Some("between 1 and 10".into());
         }
 
         if error.name.is_none() && error.quantity.is_none() {
diff --git a/book/src/types/scalars.md b/book/src/types/scalars.md
index 052fe8dc..5f2f44b0 100644
--- a/book/src/types/scalars.md
+++ b/book/src/types/scalars.md
@@ -145,14 +145,13 @@ impl UserId {
         S: ScalarValue
     {
         input.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", input))
+            .ok_or_else(|| format!("Expected `String`, found: {input}"))
             .and_then(|str| {
                 str.strip_prefix("id: ")
                     .ok_or_else(|| {
                         format!(
                             "Expected `UserId` to begin with `id: `, \
-                             found: {}",
-                            input,
+                             found: {input}",
                         )
                     })
             })
@@ -190,7 +189,7 @@ where
     S: ScalarValue
 {
     match v {
-        StringOrInt::String(str) => Value::scalar(str.to_owned()),
+        StringOrInt::String(s) => Value::scalar(s.to_owned()),
         StringOrInt::Int(i) => Value::scalar(*i),
     }
 }
@@ -200,9 +199,9 @@ where
     S: ScalarValue
 {
     v.as_string_value()
-        .map(|s| StringOrInt::String(s.to_owned()))
+        .map(|s| StringOrInt::String(s.into()))
         .or_else(|| v.as_int_value().map(|i| StringOrInt::Int(i)))
-        .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+        .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
 }
 
 fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -240,7 +239,7 @@ enum StringOrInt {
 impl StringOrInt {
     fn to_output<S: ScalarValue>(&self) -> Value<S> {
         match self {
-            Self::String(str) => Value::scalar(str.to_owned()),
+            Self::String(s) => Value::scalar(s.to_owned()),
             Self::Int(i) => Value::scalar(*i),
         }
     }
@@ -250,9 +249,9 @@ impl StringOrInt {
         S: ScalarValue,
     {
         v.as_string_value()
-            .map(|s| Self::String(s.to_owned()))
+            .map(|s| Self::String(s.into()))
             .or_else(|| v.as_int_value().map(Self::Int))
-            .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
     }
   
     fn parse_token<S>(value: ScalarToken<'_>) -> ParseScalarResult<S>
@@ -290,7 +289,7 @@ mod string_or_int {
         S: ScalarValue,
     {
         match v {
-            StringOrInt::String(str) => Value::scalar(str.to_owned()),
+            StringOrInt::String(s) => Value::scalar(s.to_owned()),
             StringOrInt::Int(i) => Value::scalar(*i),
         }
     }
@@ -300,9 +299,9 @@ mod string_or_int {
         S: ScalarValue,
     {
         v.as_string_value()
-            .map(|s| StringOrInt::String(s.to_owned()))
+            .map(|s| StringOrInt::String(s.into()))
             .or_else(|| v.as_int_value().map(StringOrInt::Int))
-            .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
     }
   
     pub(super) fn parse_token<S>(value: ScalarToken<'_>) -> ParseScalarResult<S>
@@ -335,7 +334,7 @@ impl StringOrInt {
         S: ScalarValue,
     {
         match self {
-            Self::String(str) => Value::scalar(str.to_owned()),
+            Self::String(s) => Value::scalar(s.to_owned()),
             Self::Int(i) => Value::scalar(*i),
         }
     }
@@ -345,9 +344,9 @@ impl StringOrInt {
         S: ScalarValue,
     {
         v.as_string_value()
-            .map(|s| Self::String(s.to_owned()))
+            .map(|s| Self::String(s.into()))
             .or_else(|| v.as_int_value().map(Self::Int))
-            .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
     }
 }
 #
@@ -400,8 +399,8 @@ mod date_scalar {
 
     pub(super) fn from_input(v: &InputValue<CustomScalarValue>) -> Result<Date, String> {
       v.as_string_value()
-          .ok_or_else(|| format!("Expected `String`, found: {}", v))
-          .and_then(|s| s.parse().map_err(|e| format!("Failed to parse `Date`: {}", e)))
+          .ok_or_else(|| format!("Expected `String`, found: {v}"))
+          .and_then(|s| s.parse().map_err(|e| format!("Failed to parse `Date`: {e}")))
     }
 }
 #
diff --git a/book/tests/Cargo.toml b/book/tests/Cargo.toml
index f73d6fb9..395a3d14 100644
--- a/book/tests/Cargo.toml
+++ b/book/tests/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "juniper_book_tests"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 authors = ["Magnus Hallin <mhallin@fastmail.com>"]
 publish = false
 
diff --git a/examples/actix_subscriptions/Cargo.toml b/examples/actix_subscriptions/Cargo.toml
index 9bab7b3b..9c200447 100644
--- a/examples/actix_subscriptions/Cargo.toml
+++ b/examples/actix_subscriptions/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "example_actix_subscriptions"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 authors = ["Mihai Dinculescu <mihai.dinculescu@outlook.com>"]
 publish = false
 
diff --git a/examples/actix_subscriptions/src/main.rs b/examples/actix_subscriptions/src/main.rs
index 66480242..6747105f 100644
--- a/examples/actix_subscriptions/src/main.rs
+++ b/examples/actix_subscriptions/src/main.rs
@@ -9,9 +9,9 @@ use actix_web::{
 };
 
 use juniper::{
-    graphql_object, graphql_subscription, graphql_value,
+    graphql_subscription, graphql_value,
     tests::fixtures::starwars::schema::{Database, Query},
-    EmptyMutation, FieldError, RootNode,
+    EmptyMutation, FieldError, GraphQLObject, RootNode,
 };
 use juniper_actix::{graphql_handler, playground_handler, subscriptions::subscriptions_handler};
 use juniper_graphql_ws::ConnectionConfig;
@@ -37,23 +37,12 @@ async fn graphql(
 
 struct Subscription;
 
+#[derive(GraphQLObject)]
 struct RandomHuman {
     id: String,
     name: String,
 }
 
-// TODO: remove this when async interfaces are merged
-#[graphql_object(context = Database)]
-impl RandomHuman {
-    fn id(&self) -> &str {
-        &self.id
-    }
-
-    fn name(&self) -> &str {
-        &self.name
-    }
-}
-
 type RandomHumanStream =
     Pin<Box<dyn futures::Stream<Item = Result<RandomHuman, FieldError>> + Send>>;
 
@@ -84,8 +73,8 @@ impl Subscription {
                     let human = context.get_human(&random_id).unwrap().clone();
 
                     yield Ok(RandomHuman {
-                        id: human.id().to_owned(),
-                        name: human.name().unwrap().to_owned(),
+                        id: human.id().into(),
+                        name: human.name().unwrap().into(),
                     })
                 }
             }
@@ -142,7 +131,7 @@ async fn main() -> std::io::Result<()> {
                     .finish()
             }))
     })
-    .bind(format!("{}:{}", "127.0.0.1", 8080))?
+    .bind("127.0.0.1:8080")?
     .run()
     .await
 }
diff --git a/examples/basic_subscriptions/Cargo.toml b/examples/basic_subscriptions/Cargo.toml
index f03bdef4..252bdbeb 100644
--- a/examples/basic_subscriptions/Cargo.toml
+++ b/examples/basic_subscriptions/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "example_basic_subscriptions"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 authors = ["Jordao Rosario <jordao.rosario01@gmail.com>"]
 publish = false
 
diff --git a/examples/basic_subscriptions/src/main.rs b/examples/basic_subscriptions/src/main.rs
index 82d4b46f..df523674 100644
--- a/examples/basic_subscriptions/src/main.rs
+++ b/examples/basic_subscriptions/src/main.rs
@@ -16,7 +16,7 @@ impl juniper::Context for Database {}
 
 impl Database {
     fn new() -> Self {
-        Self {}
+        Self
     }
 }
 
@@ -45,7 +45,7 @@ impl Subscription {
 type Schema = RootNode<'static, Query, EmptyMutation<Database>, Subscription>;
 
 fn schema() -> Schema {
-    Schema::new(Query {}, EmptyMutation::new(), Subscription {})
+    Schema::new(Query, EmptyMutation::new(), Subscription)
 }
 
 #[tokio::main]
diff --git a/examples/warp_async/Cargo.toml b/examples/warp_async/Cargo.toml
index 94208317..0f891304 100644
--- a/examples/warp_async/Cargo.toml
+++ b/examples/warp_async/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "example_warp_async"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 authors = ["Christoph Herzog <chris@theduke.at>"]
 publish = false
 
diff --git a/examples/warp_subscriptions/Cargo.toml b/examples/warp_subscriptions/Cargo.toml
index 6e22c5a7..da05cf99 100644
--- a/examples/warp_subscriptions/Cargo.toml
+++ b/examples/warp_subscriptions/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "example_warp_subscriptions"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 publish = false
 
 [dependencies]
diff --git a/examples/warp_subscriptions/src/main.rs b/examples/warp_subscriptions/src/main.rs
index abac06a5..4e4d4584 100644
--- a/examples/warp_subscriptions/src/main.rs
+++ b/examples/warp_subscriptions/src/main.rs
@@ -12,7 +12,7 @@ use juniper_warp::{playground_filter, subscriptions::serve_graphql_ws};
 use warp::{http::Response, Filter};
 
 #[derive(Clone)]
-struct Context {}
+struct Context;
 
 impl juniper::Context for Context {}
 
@@ -123,7 +123,7 @@ impl Subscription {
                     yield Ok(User {
                         id: counter,
                         kind: UserKind::Admin,
-                        name: "stream user".to_string(),
+                        name: "stream user".into(),
                     })
                 }
             }
@@ -149,11 +149,11 @@ async fn main() {
     let homepage = warp::path::end().map(|| {
         Response::builder()
             .header("content-type", "text/html")
-            .body("<html><h1>juniper_subscriptions demo</h1><div>visit <a href=\"/playground\">graphql playground</a></html>".to_string())
+            .body("<html><h1>juniper_subscriptions demo</h1><div>visit <a href=\"/playground\">graphql playground</a></html>")
     });
 
     let qm_schema = schema();
-    let qm_state = warp::any().map(move || Context {});
+    let qm_state = warp::any().map(|| Context);
     let qm_graphql_filter = juniper_warp::make_graphql_filter(qm_schema, qm_state.boxed());
 
     let root_node = Arc::new(schema());
@@ -165,10 +165,10 @@ async fn main() {
         .map(move |ws: warp::ws::Ws| {
             let root_node = root_node.clone();
             ws.on_upgrade(move |websocket| async move {
-                serve_graphql_ws(websocket, root_node, ConnectionConfig::new(Context {}))
+                serve_graphql_ws(websocket, root_node, ConnectionConfig::new(Context))
                     .map(|r| {
                         if let Err(e) = r {
-                            println!("Websocket error: {}", e);
+                            println!("Websocket error: {e}");
                         }
                     })
                     .await
diff --git a/juniper/Cargo.toml b/juniper/Cargo.toml
index bbf55964..6a1121aa 100644
--- a/juniper/Cargo.toml
+++ b/juniper/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper"
 version = "0.16.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "GraphQL server library."
 license = "BSD-2-Clause"
 authors = [
diff --git a/juniper/src/ast.rs b/juniper/src/ast.rs
index 2336138b..0358dd83 100644
--- a/juniper/src/ast.rs
+++ b/juniper/src/ast.rs
@@ -224,10 +224,10 @@ impl<'a> Type<'a> {
 impl<'a> fmt::Display for Type<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            Self::Named(n) => write!(f, "{}", n),
-            Self::NonNullNamed(n) => write!(f, "{}!", n),
-            Self::List(t, _) => write!(f, "[{}]", t),
-            Self::NonNullList(t, _) => write!(f, "[{}]!", t),
+            Self::Named(n) => write!(f, "{n}"),
+            Self::NonNullNamed(n) => write!(f, "{n}!"),
+            Self::List(t, _) => write!(f, "[{t}]"),
+            Self::NonNullList(t, _) => write!(f, "[{t}]!"),
         }
     }
 }
@@ -248,12 +248,12 @@ impl<S> InputValue<S> {
 
     /// Construct an enum value.
     pub fn enum_value<T: AsRef<str>>(s: T) -> Self {
-        Self::Enum(s.as_ref().to_owned())
+        Self::Enum(s.as_ref().into())
     }
 
     /// Construct a variable value.
     pub fn variable<T: AsRef<str>>(v: T) -> Self {
-        Self::Variable(v.as_ref().to_owned())
+        Self::Variable(v.as_ref().into())
     }
 
     /// Construct a [`Spanning::unlocated`] list.
@@ -282,7 +282,7 @@ impl<S> InputValue<S> {
             o.into_iter()
                 .map(|(k, v)| {
                     (
-                        Spanning::unlocated(k.as_ref().to_owned()),
+                        Spanning::unlocated(k.as_ref().into()),
                         Spanning::unlocated(v),
                     )
                 })
@@ -467,13 +467,13 @@ impl<S: ScalarValue> fmt::Display for InputValue<S> {
             Self::Null => write!(f, "null"),
             Self::Scalar(s) => {
                 if let Some(s) = s.as_str() {
-                    write!(f, "\"{}\"", s)
+                    write!(f, "\"{s}\"")
                 } else {
-                    write!(f, "{}", s)
+                    write!(f, "{s}")
                 }
             }
-            Self::Enum(v) => write!(f, "{}", v),
-            Self::Variable(v) => write!(f, "${}", v),
+            Self::Enum(v) => write!(f, "{v}"),
+            Self::Variable(v) => write!(f, "${v}"),
             Self::List(v) => {
                 write!(f, "[")?;
                 for (i, spanning) in v.iter().enumerate() {
@@ -588,30 +588,30 @@ mod tests {
     #[test]
     fn test_input_value_fmt() {
         let value: InputValue = graphql_input_value!(null);
-        assert_eq!(format!("{}", value), "null");
+        assert_eq!(value.to_string(), "null");
 
         let value: InputValue = graphql_input_value!(123);
-        assert_eq!(format!("{}", value), "123");
+        assert_eq!(value.to_string(), "123");
 
         let value: InputValue = graphql_input_value!(12.3);
-        assert_eq!(format!("{}", value), "12.3");
+        assert_eq!(value.to_string(), "12.3");
 
         let value: InputValue = graphql_input_value!("FOO");
-        assert_eq!(format!("{}", value), "\"FOO\"");
+        assert_eq!(value.to_string(), "\"FOO\"");
 
         let value: InputValue = graphql_input_value!(true);
-        assert_eq!(format!("{}", value), "true");
+        assert_eq!(value.to_string(), "true");
 
         let value: InputValue = graphql_input_value!(BAR);
-        assert_eq!(format!("{}", value), "BAR");
+        assert_eq!(value.to_string(), "BAR");
 
         let value: InputValue = graphql_input_value!(@baz);
-        assert_eq!(format!("{}", value), "$baz");
+        assert_eq!(value.to_string(), "$baz");
 
         let value: InputValue = graphql_input_value!([1, 2]);
-        assert_eq!(format!("{}", value), "[1, 2]");
+        assert_eq!(value.to_string(), "[1, 2]");
 
         let value: InputValue = graphql_input_value!({"foo": 1,"bar": 2});
-        assert_eq!(format!("{}", value), "{foo: 1, bar: 2}");
+        assert_eq!(value.to_string(), "{foo: 1, bar: 2}");
     }
 }
diff --git a/juniper/src/executor/look_ahead.rs b/juniper/src/executor/look_ahead.rs
index 41bae7ee..b12231d6 100644
--- a/juniper/src/executor/look_ahead.rs
+++ b/juniper/src/executor/look_ahead.rs
@@ -112,12 +112,11 @@ pub struct LookAheadSelection<'a, S: 'a> {
     pub(super) children: Vec<ChildSelection<'a, S>>,
 }
 
-impl<'a, S> Default for LookAheadSelection<'a, S>
-where
-    S: ScalarValue,
-{
+// Implemented manually to omit redundant `S: Default` trait bound, imposed by
+// `#[derive(Default)]`.
+impl<'a, S: 'a> Default for LookAheadSelection<'a, S> {
     fn default() -> Self {
-        LookAheadSelection {
+        Self {
             name: "",
             alias: None,
             arguments: vec![],
diff --git a/juniper/src/executor/mod.rs b/juniper/src/executor/mod.rs
index 887091c7..9ab412d4 100644
--- a/juniper/src/executor/mod.rs
+++ b/juniper/src/executor/mod.rs
@@ -304,7 +304,7 @@ where
     type Type;
 
     #[doc(hidden)]
-    fn into(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S>;
+    fn into_resolvable(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S>;
 }
 
 impl<'a, S, T, C> IntoResolvable<'a, S, T, C> for T
@@ -315,7 +315,7 @@ where
 {
     type Type = T;
 
-    fn into(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
+    fn into_resolvable(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
         Ok(Some((FromContext::from(ctx), self)))
     }
 }
@@ -328,7 +328,7 @@ where
 {
     type Type = T;
 
-    fn into(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
+    fn into_resolvable(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
         self.map(|v: T| Some((<T::Context as FromContext<C>>::from(ctx), v)))
             .map_err(IntoFieldError::into_field_error)
     }
@@ -341,7 +341,7 @@ where
 {
     type Type = T;
 
-    fn into(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
+    fn into_resolvable(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S> {
         Ok(Some(self))
     }
 }
@@ -354,7 +354,7 @@ where
     type Type = T;
 
     #[allow(clippy::type_complexity)]
-    fn into(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, Option<T>)>, S> {
+    fn into_resolvable(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, Option<T>)>, S> {
         Ok(self.map(|(ctx, v)| (ctx, Some(v))))
     }
 }
@@ -367,7 +367,7 @@ where
 {
     type Type = T;
 
-    fn into(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S2> {
+    fn into_resolvable(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S2> {
         self.map(Some).map_err(FieldError::map_scalar_value)
     }
 }
@@ -382,7 +382,7 @@ where
     type Type = T;
 
     #[allow(clippy::type_complexity)]
-    fn into(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, Option<T>)>, S2> {
+    fn into_resolvable(self, _: &'a C) -> FieldResult<Option<(&'a T::Context, Option<T>)>, S2> {
         self.map(|o| o.map(|(ctx, v)| (ctx, Some(v))))
             .map_err(FieldError::map_scalar_value)
     }
@@ -774,7 +774,7 @@ impl<'a> FieldPath<'a> {
             FieldPath::Root(_) => (),
             FieldPath::Field(name, _, parent) => {
                 parent.construct_path(acc);
-                acc.push((*name).to_owned());
+                acc.push((*name).into());
             }
         }
     }
@@ -791,7 +791,7 @@ impl<S> ExecutionError<S> {
     pub fn new(location: SourcePosition, path: &[&str], error: FieldError<S>) -> ExecutionError<S> {
         ExecutionError {
             location,
-            path: path.iter().map(|s| (*s).to_owned()).collect(),
+            path: path.iter().map(|s| (*s).into()).collect(),
             error,
         }
     }
@@ -842,10 +842,10 @@ where
         defs.item
             .items
             .iter()
-            .filter_map(|&(ref name, ref def)| {
+            .filter_map(|(name, def)| {
                 def.default_value
                     .as_ref()
-                    .map(|i| (name.item.to_owned(), i.item.clone()))
+                    .map(|i| (name.item.into(), i.item.clone()))
             })
             .collect::<HashMap<String, InputValue<S>>>()
     });
@@ -943,7 +943,7 @@ where
             .filter_map(|&(ref name, ref def)| {
                 def.default_value
                     .as_ref()
-                    .map(|i| (name.item.to_owned(), i.item.clone()))
+                    .map(|i| (name.item.into(), i.item.clone()))
             })
             .collect::<HashMap<String, InputValue<S>>>()
     });
@@ -1090,7 +1090,7 @@ where
             .filter_map(|&(ref name, ref def)| {
                 def.default_value
                     .as_ref()
-                    .map(|i| (name.item.to_owned(), i.item.clone()))
+                    .map(|i| (name.item.into(), i.item.clone()))
             })
             .collect::<HashMap<String, InputValue<S>>>()
     });
@@ -1172,7 +1172,7 @@ impl<'r, S: 'r> Registry<'r, S> {
             if !self.types.contains_key(name) {
                 self.insert_placeholder(
                     validated_name.clone(),
-                    Type::NonNullNamed(Cow::Owned(name.to_string())),
+                    Type::NonNullNamed(Cow::Owned(name.into())),
                 );
                 let meta = T::meta(info, self);
                 self.types.insert(validated_name, meta);
@@ -1209,7 +1209,7 @@ impl<'r, S: 'r> Registry<'r, S> {
         S: ScalarValue,
     {
         Field {
-            name: smartstring::SmartString::from(name),
+            name: name.into(),
             description: None,
             arguments: None,
             field_type: self.get_type::<I>(info),
@@ -1255,7 +1255,7 @@ impl<'r, S: 'r> Registry<'r, S> {
     {
         let name = T::name(info).expect("Scalar types must be named. Implement `name()`");
 
-        ScalarMeta::new::<T>(Cow::Owned(name.to_string()))
+        ScalarMeta::new::<T>(Cow::Owned(name.into()))
     }
 
     /// Creates a [`ListMeta`] type.
@@ -1299,7 +1299,7 @@ impl<'r, S: 'r> Registry<'r, S> {
 
         let mut v = fields.to_vec();
         v.push(self.field::<String>("__typename", &()));
-        ObjectMeta::new(Cow::Owned(name.to_string()), &v)
+        ObjectMeta::new(Cow::Owned(name.into()), &v)
     }
 
     /// Creates an [`EnumMeta`] type out of the provided `values`.
@@ -1315,7 +1315,7 @@ impl<'r, S: 'r> Registry<'r, S> {
     {
         let name = T::name(info).expect("Enum types must be named. Implement `name()`");
 
-        EnumMeta::new::<T>(Cow::Owned(name.to_string()), values)
+        EnumMeta::new::<T>(Cow::Owned(name.into()), values)
     }
 
     /// Creates an [`InterfaceMeta`] type with the given `fields`.
@@ -1332,7 +1332,7 @@ impl<'r, S: 'r> Registry<'r, S> {
 
         let mut v = fields.to_vec();
         v.push(self.field::<String>("__typename", &()));
-        InterfaceMeta::new(Cow::Owned(name.to_string()), &v)
+        InterfaceMeta::new(Cow::Owned(name.into()), &v)
     }
 
     /// Creates an [`UnionMeta`] type of the given `types`.
@@ -1343,7 +1343,7 @@ impl<'r, S: 'r> Registry<'r, S> {
     {
         let name = T::name(info).expect("Union types must be named. Implement name()");
 
-        UnionMeta::new(Cow::Owned(name.to_string()), types)
+        UnionMeta::new(Cow::Owned(name.into()), types)
     }
 
     /// Creates an [`InputObjectMeta`] type with the given `args`.
@@ -1359,6 +1359,6 @@ impl<'r, S: 'r> Registry<'r, S> {
     {
         let name = T::name(info).expect("Input object types must be named. Implement name()");
 
-        InputObjectMeta::new::<T>(Cow::Owned(name.to_string()), args)
+        InputObjectMeta::new::<T>(Cow::Owned(name.into()), args)
     }
 }
diff --git a/juniper/src/executor_tests/async_await/mod.rs b/juniper/src/executor_tests/async_await/mod.rs
index 277c0197..228c53d3 100644
--- a/juniper/src/executor_tests/async_await/mod.rs
+++ b/juniper/src/executor_tests/async_await/mod.rs
@@ -1,5 +1,6 @@
 use crate::{
-    graphql_object, graphql_value, EmptyMutation, EmptySubscription, GraphQLEnum, RootNode, Value,
+    graphql_object, graphql_value, graphql_vars, EmptyMutation, EmptySubscription, GraphQLEnum,
+    RootNode, Value,
 };
 
 #[derive(GraphQLEnum)]
@@ -30,7 +31,7 @@ impl User {
         (0..10)
             .map(|index| User {
                 id: index,
-                name: format!("user{}", index),
+                name: format!("user{index}"),
                 kind: UserKind::User,
             })
             .collect()
@@ -55,7 +56,7 @@ impl Query {
     }
 
     async fn field_async_plain() -> String {
-        "field_async_plain".to_string()
+        "field_async_plain".into()
     }
 
     fn user(id: String) -> User {
@@ -86,8 +87,7 @@ async fn async_simple() {
         }
     "#;
 
-    let vars = Default::default();
-    let (res, errs) = crate::execute(doc, None, &schema, &vars, &())
+    let (res, errs) = crate::execute(doc, None, &schema, &graphql_vars! {}, &())
         .await
         .unwrap();
 
diff --git a/juniper/src/executor_tests/directives.rs b/juniper/src/executor_tests/directives.rs
index adc05594..1f902e69 100644
--- a/juniper/src/executor_tests/directives.rs
+++ b/juniper/src/executor_tests/directives.rs
@@ -35,7 +35,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let obj = result.as_object_value().expect("Result is not an object");
 
diff --git a/juniper/src/executor_tests/enums.rs b/juniper/src/executor_tests/enums.rs
index 69cda71d..11fa80ae 100644
--- a/juniper/src/executor_tests/enums.rs
+++ b/juniper/src/executor_tests/enums.rs
@@ -22,7 +22,7 @@ struct TestType;
 #[crate::graphql_object]
 impl TestType {
     fn to_string(color: Color) -> String {
-        format!("Color::{:?}", color)
+        format!("Color::{color:?}")
     }
 
     fn a_color() -> Color {
@@ -46,7 +46,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let obj = result.as_object_value().expect("Result is not an object");
 
diff --git a/juniper/src/executor_tests/executor.rs b/juniper/src/executor_tests/executor.rs
index a1da0673..06d93fc0 100644
--- a/juniper/src/executor_tests/executor.rs
+++ b/juniper/src/executor_tests/executor.rs
@@ -96,7 +96,7 @@ mod field_execution {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -180,7 +180,7 @@ mod merge_parallel_fragments {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -288,7 +288,7 @@ mod merge_parallel_inline_fragments {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -355,7 +355,7 @@ mod threads_context_correctly {
             &schema,
             &vars,
             &TestContext {
-                value: "Context value".to_owned(),
+                value: "Context value".into(),
             },
         )
         .await
@@ -363,7 +363,7 @@ mod threads_context_correctly {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!({"a": "Context value"}));
     }
@@ -410,7 +410,7 @@ mod dynamic_context_switching {
             let res = context
                 .items
                 .get(&key)
-                .ok_or(format!("Could not find key {}", key))
+                .ok_or(format!("Could not find key {key}"))
                 .map(|c| (c, ItemRef))?;
             Ok(res)
         }
@@ -420,7 +420,7 @@ mod dynamic_context_switching {
             key: i32,
         ) -> FieldResult<Option<(&InnerContext, ItemRef)>> {
             if key > 100 {
-                Err(format!("Key too large: {}", key))?;
+                Err(format!("Key too large: {key}"))?;
             }
             Ok(context.items.get(&key).map(|c| (c, ItemRef)))
         }
@@ -452,13 +452,13 @@ mod dynamic_context_switching {
                 (
                     0,
                     InnerContext {
-                        value: "First value".to_owned(),
+                        value: "First value".into(),
                     },
                 ),
                 (
                     1,
                     InnerContext {
-                        value: "Second value".to_owned(),
+                        value: "Second value".into(),
                     },
                 ),
             ]
@@ -472,7 +472,7 @@ mod dynamic_context_switching {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -500,13 +500,13 @@ mod dynamic_context_switching {
                 (
                     0,
                     InnerContext {
-                        value: "First value".to_owned(),
+                        value: "First value".into(),
                     },
                 ),
                 (
                     1,
                     InnerContext {
-                        value: "Second value".to_owned(),
+                        value: "Second value".into(),
                     },
                 ),
             ]
@@ -520,7 +520,7 @@ mod dynamic_context_switching {
 
         assert_eq!(errs, vec![]);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!({"first": {"value": "First value"}}));
     }
@@ -542,13 +542,13 @@ mod dynamic_context_switching {
                 (
                     0,
                     InnerContext {
-                        value: "First value".to_owned(),
+                        value: "First value".into(),
                     },
                 ),
                 (
                     1,
                     InnerContext {
-                        value: "Second value".to_owned(),
+                        value: "Second value".into(),
                     },
                 ),
             ]
@@ -569,7 +569,7 @@ mod dynamic_context_switching {
             )],
         );
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!(null));
     }
@@ -593,13 +593,13 @@ mod dynamic_context_switching {
                 (
                     0,
                     InnerContext {
-                        value: "First value".to_owned(),
+                        value: "First value".into(),
                     },
                 ),
                 (
                     1,
                     InnerContext {
-                        value: "Second value".to_owned(),
+                        value: "Second value".into(),
                     },
                 ),
             ]
@@ -620,7 +620,7 @@ mod dynamic_context_switching {
             )],
         );
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -647,13 +647,13 @@ mod dynamic_context_switching {
                 (
                     0,
                     InnerContext {
-                        value: "First value".to_owned(),
+                        value: "First value".into(),
                     },
                 ),
                 (
                     1,
                     InnerContext {
-                        value: "Second value".to_owned(),
+                        value: "Second value".into(),
                     },
                 ),
             ]
@@ -667,7 +667,7 @@ mod dynamic_context_switching {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!({"first": {"value": "First value"}}));
     }
@@ -752,7 +752,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -783,7 +783,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!(null));
 
@@ -811,7 +811,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!(null));
 
@@ -839,7 +839,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!({"inner": {"nullableField": null}}),);
 
@@ -867,7 +867,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!(null));
 
@@ -895,7 +895,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -926,7 +926,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(result, graphql_value!(null));
 
@@ -954,7 +954,7 @@ mod propagates_errors_to_nullable_fields {
             .await
             .expect("Execution failed");
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
diff --git a/juniper/src/executor_tests/interfaces_unions.rs b/juniper/src/executor_tests/interfaces_unions.rs
index 1044baaf..10d5e088 100644
--- a/juniper/src/executor_tests/interfaces_unions.rs
+++ b/juniper/src/executor_tests/interfaces_unions.rs
@@ -42,12 +42,12 @@ mod interface {
             Schema {
                 pets: vec![
                     Dog {
-                        name: "Odie".to_owned(),
+                        name: "Odie".into(),
                         woofs: true,
                     }
                     .into(),
                     Cat {
-                        name: "Garfield".to_owned(),
+                        name: "Garfield".into(),
                         meows: false,
                     }
                     .into(),
@@ -77,7 +77,7 @@ mod interface {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
@@ -170,11 +170,11 @@ mod union {
             Schema {
                 pets: vec![
                     Box::new(Dog {
-                        name: "Odie".to_owned(),
+                        name: "Odie".into(),
                         woofs: true,
                     }),
                     Box::new(Cat {
-                        name: "Garfield".to_owned(),
+                        name: "Garfield".into(),
                         meows: false,
                     }),
                 ],
@@ -205,7 +205,7 @@ mod union {
 
         assert_eq!(errs, []);
 
-        println!("Result: {:#?}", result);
+        println!("Result: {result:#?}");
 
         assert_eq!(
             result,
diff --git a/juniper/src/executor_tests/introspection/enums.rs b/juniper/src/executor_tests/introspection/enums.rs
index 127f45ab..c70a60e9 100644
--- a/juniper/src/executor_tests/introspection/enums.rs
+++ b/juniper/src/executor_tests/introspection/enums.rs
@@ -92,7 +92,7 @@ where
     F: Fn((&Object<DefaultScalarValue>, &Vec<Value<DefaultScalarValue>>)) -> (),
 {
     let schema = RootNode::new(
-        Root {},
+        Root,
         EmptyMutation::<()>::new(),
         EmptySubscription::<()>::new(),
     );
@@ -103,7 +103,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
diff --git a/juniper/src/executor_tests/introspection/input_object.rs b/juniper/src/executor_tests/introspection/input_object.rs
index cf8c0d20..2e70d088 100644
--- a/juniper/src/executor_tests/introspection/input_object.rs
+++ b/juniper/src/executor_tests/introspection/input_object.rs
@@ -117,7 +117,7 @@ where
     F: Fn(&Object<DefaultScalarValue>, &Vec<Value<DefaultScalarValue>>) -> (),
 {
     let schema = RootNode::new(
-        Root {},
+        Root,
         EmptyMutation::<()>::new(),
         EmptySubscription::<()>::new(),
     );
@@ -128,7 +128,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
@@ -312,7 +312,7 @@ fn derive_derived() {
         format!(
             "{:?}",
             Derive {
-                field_one: "test".to_owned(),
+                field_one: "test".into(),
             },
         ),
         "Derive { field_one: \"test\" }"
diff --git a/juniper/src/executor_tests/introspection/mod.rs b/juniper/src/executor_tests/introspection/mod.rs
index e78995ec..ee2501b2 100644
--- a/juniper/src/executor_tests/introspection/mod.rs
+++ b/juniper/src/executor_tests/introspection/mod.rs
@@ -69,7 +69,7 @@ async fn test_execution() {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     assert_eq!(
         result,
@@ -114,7 +114,7 @@ async fn enum_introspection() {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
@@ -223,7 +223,7 @@ async fn interface_introspection() {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
@@ -355,7 +355,7 @@ async fn object_introspection() {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
@@ -406,7 +406,7 @@ async fn object_introspection() {
 
     assert_eq!(fields.len(), 2);
 
-    println!("Fields: {:#?}", fields);
+    println!("Fields: {fields:#?}");
 
     assert!(fields.contains(&graphql_value!({
         "name": "sampleEnum",
@@ -497,7 +497,7 @@ async fn scalar_introspection() {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
 
     let type_info = result
         .as_object_value()
diff --git a/juniper/src/executor_tests/variables.rs b/juniper/src/executor_tests/variables.rs
index 0073d0e2..f49d4a23 100644
--- a/juniper/src/executor_tests/variables.rs
+++ b/juniper/src/executor_tests/variables.rs
@@ -23,7 +23,7 @@ impl TestComplexScalar {
         v.as_string_value()
             .filter(|s| *s == "SerializedValue")
             .map(|_| Self)
-            .ok_or_else(|| format!(r#"Expected "SerializedValue" string, found: {}"#, v))
+            .ok_or_else(|| format!(r#"Expected "SerializedValue" string, found: {v}"#))
     }
 }
 
@@ -58,47 +58,47 @@ struct TestType;
 #[graphql_object]
 impl TestType {
     fn field_with_object_input(input: Option<TestInputObject>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn field_with_nullable_string_input(input: Option<String>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn field_with_non_nullable_string_input(input: String) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn field_with_default_argument_value(
         #[graphql(default = "Hello World")] input: String,
     ) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn nullable_field_with_default_argument_value(
         #[graphql(default = "Hello World".to_owned())] input: Option<String>,
     ) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn field_with_nested_object_input(input: Option<TestNestedInputObject>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn list(input: Option<Vec<Option<String>>>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn nn_list(input: Vec<Option<String>>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn list_nn(input: Option<Vec<String>>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn nn_list_nn(input: Vec<String>) -> String {
-        format!("{:?}", input)
+        format!("{input:?}")
     }
 
     fn example_input(arg: ExampleInputObject) -> String {
@@ -110,11 +110,11 @@ impl TestType {
     }
 
     fn integer_input(value: i32) -> String {
-        format!("value: {}", value)
+        format!("value: {value}")
     }
 
     fn float_input(value: f64) -> String {
-        format!("value: {}", value)
+        format!("value: {value}")
     }
 }
 
@@ -134,7 +134,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:?}", result);
+    println!("Result: {result:?}");
 
     let obj = result.as_object_value().expect("Result is not an object");
 
diff --git a/juniper/src/http/mod.rs b/juniper/src/http/mod.rs
index fe3f2d65..45e310be 100644
--- a/juniper/src/http/mod.rs
+++ b/juniper/src/http/mod.rs
@@ -60,11 +60,8 @@ where
         self.variables
             .as_ref()
             .and_then(|iv| {
-                iv.to_object_value().map(|o| {
-                    o.into_iter()
-                        .map(|(k, v)| (k.to_owned(), v.clone()))
-                        .collect()
-                })
+                iv.to_object_value()
+                    .map(|o| o.into_iter().map(|(k, v)| (k.into(), v.clone())).collect())
             })
             .unwrap_or_default()
     }
@@ -635,20 +632,20 @@ pub mod tests {
                     "type":"connection_init",
                     "payload":{}
                 }"#
-                .to_owned(),
+                .into(),
             ),
             WsIntegrationMessage::Expect(
                 r#"{
                     "type":"connection_ack"
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT,
             ),
             WsIntegrationMessage::Expect(
                 r#"{
                     "type":"ka"
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT,
             ),
             WsIntegrationMessage::Send(
@@ -662,7 +659,7 @@ pub mod tests {
                         "query":"subscription { asyncHuman { id, name, homePlanet } }"
                     }
                 }"#
-                .to_owned(),
+                .into(),
             ),
             WsIntegrationMessage::Expect(
                 r#"{
@@ -678,7 +675,7 @@ pub mod tests {
                         }
                     }
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT,
             ),
         ];
@@ -688,7 +685,7 @@ pub mod tests {
 
     async fn test_ws_invalid_json<T: WsIntegration>(integration: &T) {
         let messages = vec![
-            WsIntegrationMessage::Send("invalid json".to_owned()),
+            WsIntegrationMessage::Send("invalid json".into()),
             WsIntegrationMessage::Expect(
                 r#"{
                     "type":"connection_error",
@@ -696,7 +693,7 @@ pub mod tests {
                         "message":"serde error: expected value at line 1 column 1"
                     }
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT,
             ),
         ];
@@ -711,20 +708,20 @@ pub mod tests {
                     "type":"connection_init",
                     "payload":{}
                 }"#
-                .to_owned(),
+                .into(),
             ),
             WsIntegrationMessage::Expect(
                 r#"{
                     "type":"connection_ack"
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT
             ),
             WsIntegrationMessage::Expect(
                 r#"{
                     "type":"ka"
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT
             ),
             WsIntegrationMessage::Send(
@@ -738,7 +735,7 @@ pub mod tests {
                         "query":"subscription { asyncHuman }"
                     }
                 }"#
-                .to_owned(),
+                .into(),
             ),
             WsIntegrationMessage::Expect(
                 r#"{
@@ -752,7 +749,7 @@ pub mod tests {
                         }]
                     }]
                 }"#
-                .to_owned(),
+                .into(),
                 WS_INTEGRATION_EXPECT_DEFAULT_TIMEOUT
             )
         ];
diff --git a/juniper/src/integrations/bigdecimal.rs b/juniper/src/integrations/bigdecimal.rs
index a1635fcc..3715536c 100644
--- a/juniper/src/integrations/bigdecimal.rs
+++ b/juniper/src/integrations/bigdecimal.rs
@@ -32,8 +32,6 @@ use crate::{graphql_scalar, InputValue, ScalarValue, Value};
 type BigDecimal = bigdecimal::BigDecimal;
 
 mod bigdecimal_scalar {
-    use std::convert::TryFrom as _;
-
     use super::*;
 
     pub(super) fn to_output<S: ScalarValue>(v: &BigDecimal) -> Value<S> {
@@ -45,13 +43,13 @@ mod bigdecimal_scalar {
             Ok(BigDecimal::from(i))
         } else if let Some(f) = v.as_float_value() {
             BigDecimal::try_from(f)
-                .map_err(|e| format!("Failed to parse `BigDecimal` from `Float`: {}", e))
+                .map_err(|e| format!("Failed to parse `BigDecimal` from `Float`: {e}"))
         } else {
             v.as_string_value()
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
                 .and_then(|s| {
                     BigDecimal::from_str(s)
-                        .map_err(|e| format!("Failed to parse `BigDecimal` from `String`: {}", e))
+                        .map_err(|e| format!("Failed to parse `BigDecimal` from `String`: {e}"))
                 })
         }
     }
@@ -88,11 +86,10 @@ mod test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{:?}`: {:?}",
-                input,
+                "failed to parse `{input:?}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {:?}", input);
+            assert_eq!(parsed.unwrap(), expected, "input: {input:?}");
         }
     }
 
@@ -110,7 +107,7 @@ mod test {
             let input: InputValue = input;
             let parsed = BigDecimal::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -126,7 +123,7 @@ mod test {
         ] {
             let actual: InputValue = BigDecimal::from_str(raw).unwrap().to_input_value();
 
-            assert_eq!(actual, graphql_input_value!((raw)), "on value: {}", raw);
+            assert_eq!(actual, graphql_input_value!((raw)), "on value: {raw}");
         }
     }
 }
diff --git a/juniper/src/integrations/bson.rs b/juniper/src/integrations/bson.rs
index 8d904025..20c88fbe 100644
--- a/juniper/src/integrations/bson.rs
+++ b/juniper/src/integrations/bson.rs
@@ -14,9 +14,9 @@ mod object_id {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<ObjectId, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
-                ObjectId::parse_str(s).map_err(|e| format!("Failed to parse `ObjectId`: {}", e))
+                ObjectId::parse_str(s).map_err(|e| format!("Failed to parse `ObjectId`: {e}"))
             })
     }
 }
@@ -30,16 +30,16 @@ mod utc_date_time {
     pub(super) fn to_output<S: ScalarValue>(v: &UtcDateTime) -> Value<S> {
         Value::scalar(
             (*v).try_to_rfc3339_string()
-                .unwrap_or_else(|e| panic!("failed to format `UtcDateTime` as RFC3339: {}", e)),
+                .unwrap_or_else(|e| panic!("failed to format `UtcDateTime` as RFC3339: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<UtcDateTime, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 UtcDateTime::parse_rfc3339_str(s)
-                    .map_err(|e| format!("Failed to parse `UtcDateTime`: {}", e))
+                    .map_err(|e| format!("Failed to parse `UtcDateTime`: {e}"))
             })
     }
 }
diff --git a/juniper/src/integrations/chrono.rs b/juniper/src/integrations/chrono.rs
index a0c6edc4..b1fb3a48 100644
--- a/juniper/src/integrations/chrono.rs
+++ b/juniper/src/integrations/chrono.rs
@@ -62,9 +62,9 @@ mod date {
         S: ScalarValue,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
-                Date::parse_from_str(s, FORMAT).map_err(|e| format!("Invalid `Date`: {}", e))
+                Date::parse_from_str(s, FORMAT).map_err(|e| format!("Invalid `Date`: {e}"))
             })
     }
 }
@@ -127,7 +127,7 @@ mod local_time {
         S: ScalarValue,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 // First, try to parse the most used format.
                 // At the end, try to parse the full format for the parsing
@@ -135,7 +135,7 @@ mod local_time {
                 LocalTime::parse_from_str(s, FORMAT_NO_MILLIS)
                     .or_else(|_| LocalTime::parse_from_str(s, FORMAT_NO_SECS))
                     .or_else(|_| LocalTime::parse_from_str(s, FORMAT))
-                    .map_err(|e| format!("Invalid `LocalTime`: {}", e))
+                    .map_err(|e| format!("Invalid `LocalTime`: {e}"))
             })
     }
 }
@@ -166,10 +166,10 @@ mod local_date_time {
         S: ScalarValue,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 LocalDateTime::parse_from_str(s, FORMAT)
-                    .map_err(|e| format!("Invalid `LocalDateTime`: {}", e))
+                    .map_err(|e| format!("Invalid `LocalDateTime`: {e}"))
             })
     }
 }
@@ -219,10 +219,10 @@ mod date_time {
         Tz: TimeZone + FromFixedOffset,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 DateTime::<FixedOffset>::parse_from_rfc3339(s)
-                    .map_err(|e| format!("Invalid `DateTime`: {}", e))
+                    .map_err(|e| format!("Invalid `DateTime`: {e}"))
                     .map(FromFixedOffset::from_fixed_offset)
             })
     }
@@ -345,11 +345,10 @@ mod date_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -372,7 +371,7 @@ mod date_test {
             let input: InputValue = input;
             let parsed = Date::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -394,7 +393,7 @@ mod date_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -420,11 +419,10 @@ mod local_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -451,7 +449,7 @@ mod local_time_test {
             let input: InputValue = input;
             let parsed = LocalTime::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -477,7 +475,7 @@ mod local_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -513,11 +511,10 @@ mod local_date_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -546,7 +543,7 @@ mod local_date_time_test {
             let input: InputValue = input;
             let parsed = LocalDateTime::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -570,7 +567,7 @@ mod local_date_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -635,11 +632,10 @@ mod date_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -673,7 +669,7 @@ mod date_time_test {
             let input: InputValue = input;
             let parsed = DateTime::<FixedOffset>::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -703,7 +699,7 @@ mod date_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
diff --git a/juniper/src/integrations/chrono_tz.rs b/juniper/src/integrations/chrono_tz.rs
index b6fa5732..8950f97f 100644
--- a/juniper/src/integrations/chrono_tz.rs
+++ b/juniper/src/integrations/chrono_tz.rs
@@ -34,10 +34,10 @@ mod tz {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<TimeZone, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 s.parse::<TimeZone>()
-                    .map_err(|e| format!("Failed to parse `TimeZone`: {}", e))
+                    .map_err(|e| format!("Failed to parse `TimeZone`: {e}"))
             })
     }
 }
diff --git a/juniper/src/integrations/rust_decimal.rs b/juniper/src/integrations/rust_decimal.rs
index 2e74db32..52a6d20c 100644
--- a/juniper/src/integrations/rust_decimal.rs
+++ b/juniper/src/integrations/rust_decimal.rs
@@ -34,8 +34,6 @@ use crate::{graphql_scalar, InputValue, ScalarValue, Value};
 type Decimal = rust_decimal::Decimal;
 
 mod rust_decimal_scalar {
-    use std::convert::TryFrom as _;
-
     use super::*;
 
     pub(super) fn to_output<S: ScalarValue>(v: &Decimal) -> Value<S> {
@@ -46,14 +44,13 @@ mod rust_decimal_scalar {
         if let Some(i) = v.as_int_value() {
             Ok(Decimal::from(i))
         } else if let Some(f) = v.as_float_value() {
-            Decimal::try_from(f)
-                .map_err(|e| format!("Failed to parse `Decimal` from `Float`: {}", e))
+            Decimal::try_from(f).map_err(|e| format!("Failed to parse `Decimal` from `Float`: {e}"))
         } else {
             v.as_string_value()
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
                 .and_then(|s| {
                     Decimal::from_str(s)
-                        .map_err(|e| format!("Failed to parse `Decimal` from `String`: {}", e))
+                        .map_err(|e| format!("Failed to parse `Decimal` from `String`: {e}"))
                 })
         }
     }
@@ -84,11 +81,10 @@ mod test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{:?}`: {:?}",
-                input,
+                "failed to parse `{input:?}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {:?}", input);
+            assert_eq!(parsed.unwrap(), expected, "input: {input:?}");
         }
     }
 
@@ -108,7 +104,7 @@ mod test {
             let input: InputValue = input;
             let parsed = Decimal::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -117,7 +113,7 @@ mod test {
         for raw in ["4.20", "0", "999.999999999", "875533788", "123", "43.44"] {
             let actual: InputValue = Decimal::from_str(raw).unwrap().to_input_value();
 
-            assert_eq!(actual, graphql_input_value!((raw)), "on value: {}", raw);
+            assert_eq!(actual, graphql_input_value!((raw)), "on value: {raw}");
         }
     }
 }
diff --git a/juniper/src/integrations/serde.rs b/juniper/src/integrations/serde.rs
index 64b5018f..38779964 100644
--- a/juniper/src/integrations/serde.rs
+++ b/juniper/src/integrations/serde.rs
@@ -1,8 +1,4 @@
-use std::{
-    convert::{TryFrom as _, TryInto as _},
-    fmt,
-    marker::PhantomData,
-};
+use std::{fmt, marker::PhantomData};
 
 use indexmap::IndexMap;
 use serde::{
@@ -251,7 +247,7 @@ impl Serialize for Spanning<ParseError> {
     fn serialize<S: Serializer>(&self, ser: S) -> Result<S::Ok, S::Error> {
         let mut map = ser.serialize_map(Some(2))?;
 
-        let msg = format!("{}", self.item);
+        let msg = self.item.to_string();
         map.serialize_key("message")?;
         map.serialize_value(&msg)?;
 
@@ -396,7 +392,7 @@ mod tests {
     #[test]
     fn error_extensions() {
         let mut obj: Object<DefaultScalarValue> = Object::with_capacity(1);
-        obj.add_field("foo".to_string(), Value::scalar("bar"));
+        obj.add_field("foo", Value::scalar("bar"));
         assert_eq!(
             to_string(&ExecutionError::at_origin(FieldError::new(
                 "foo error",
diff --git a/juniper/src/integrations/time.rs b/juniper/src/integrations/time.rs
index e05bf535..d2c88529 100644
--- a/juniper/src/integrations/time.rs
+++ b/juniper/src/integrations/time.rs
@@ -57,14 +57,14 @@ mod date {
     pub(super) fn to_output<S: ScalarValue>(v: &Date) -> Value<S> {
         Value::scalar(
             v.format(FORMAT)
-                .unwrap_or_else(|e| panic!("Failed to format `Date`: {}", e)),
+                .unwrap_or_else(|e| panic!("Failed to format `Date`: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Date, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
-            .and_then(|s| Date::parse(s, FORMAT).map_err(|e| format!("Invalid `Date`: {}", e)))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
+            .and_then(|s| Date::parse(s, FORMAT).map_err(|e| format!("Invalid `Date`: {e}")))
     }
 }
 
@@ -109,13 +109,13 @@ mod local_time {
             } else {
                 v.format(FORMAT)
             }
-            .unwrap_or_else(|e| panic!("Failed to format `LocalTime`: {}", e)),
+            .unwrap_or_else(|e| panic!("Failed to format `LocalTime`: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<LocalTime, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 // First, try to parse the most used format.
                 // At the end, try to parse the full format for the parsing
@@ -123,7 +123,7 @@ mod local_time {
                 LocalTime::parse(s, FORMAT_NO_MILLIS)
                     .or_else(|_| LocalTime::parse(s, FORMAT_NO_SECS))
                     .or_else(|_| LocalTime::parse(s, FORMAT))
-                    .map_err(|e| format!("Invalid `LocalTime`: {}", e))
+                    .map_err(|e| format!("Invalid `LocalTime`: {e}"))
             })
     }
 }
@@ -146,16 +146,15 @@ mod local_date_time {
     pub(super) fn to_output<S: ScalarValue>(v: &LocalDateTime) -> Value<S> {
         Value::scalar(
             v.format(FORMAT)
-                .unwrap_or_else(|e| panic!("Failed to format `LocalDateTime`: {}", e)),
+                .unwrap_or_else(|e| panic!("Failed to format `LocalDateTime`: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<LocalDateTime, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
-                LocalDateTime::parse(s, FORMAT)
-                    .map_err(|e| format!("Invalid `LocalDateTime`: {}", e))
+                LocalDateTime::parse(s, FORMAT).map_err(|e| format!("Invalid `LocalDateTime`: {e}"))
             })
     }
 }
@@ -186,15 +185,15 @@ mod date_time {
         Value::scalar(
             v.to_offset(UtcOffset::UTC)
                 .format(&Rfc3339)
-                .unwrap_or_else(|e| panic!("Failed to format `DateTime`: {}", e)),
+                .unwrap_or_else(|e| panic!("Failed to format `DateTime`: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<DateTime, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
-                DateTime::parse(s, &Rfc3339).map_err(|e| format!("Invalid `DateTime`: {}", e))
+                DateTime::parse(s, &Rfc3339).map_err(|e| format!("Invalid `DateTime`: {e}"))
             })
             .map(|dt| dt.to_offset(UtcOffset::UTC))
     }
@@ -228,16 +227,16 @@ mod utc_offset {
     pub(super) fn to_output<S: ScalarValue>(v: &UtcOffset) -> Value<S> {
         Value::scalar(
             v.format(UTC_OFFSET_FORMAT)
-                .unwrap_or_else(|e| panic!("Failed to format `UtcOffset`: {}", e)),
+                .unwrap_or_else(|e| panic!("Failed to format `UtcOffset`: {e}")),
         )
     }
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<UtcOffset, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 UtcOffset::parse(s, UTC_OFFSET_FORMAT)
-                    .map_err(|e| format!("Invalid `UtcOffset`: {}", e))
+                    .map_err(|e| format!("Invalid `UtcOffset`: {e}"))
             })
     }
 }
@@ -261,11 +260,10 @@ mod date_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -288,7 +286,7 @@ mod date_test {
             let input: InputValue = input;
             let parsed = Date::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -302,7 +300,7 @@ mod date_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -330,11 +328,10 @@ mod local_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -364,7 +361,7 @@ mod local_time_test {
             let input: InputValue = input;
             let parsed = LocalTime::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -378,7 +375,7 @@ mod local_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -402,11 +399,10 @@ mod local_date_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -437,7 +433,7 @@ mod local_date_time_test {
             let input: InputValue = input;
             let parsed = LocalDateTime::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -455,7 +451,7 @@ mod local_date_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -490,11 +486,10 @@ mod date_time_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -528,7 +523,7 @@ mod date_time_test {
             let input: InputValue = input;
             let parsed = DateTime::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -546,7 +541,7 @@ mod date_time_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
@@ -574,11 +569,10 @@ mod utc_offset_test {
 
             assert!(
                 parsed.is_ok(),
-                "failed to parse `{}`: {:?}",
-                raw,
+                "failed to parse `{raw}`: {:?}",
                 parsed.unwrap_err(),
             );
-            assert_eq!(parsed.unwrap(), expected, "input: {}", raw);
+            assert_eq!(parsed.unwrap(), expected, "input: {raw}");
         }
     }
 
@@ -607,7 +601,7 @@ mod utc_offset_test {
             let input: InputValue = input;
             let parsed = UtcOffset::from_input_value(&input);
 
-            assert!(parsed.is_err(), "allows input: {:?}", input);
+            assert!(parsed.is_err(), "allows input: {input:?}");
         }
     }
 
@@ -620,7 +614,7 @@ mod utc_offset_test {
         ] {
             let actual: InputValue = val.to_input_value();
 
-            assert_eq!(actual, expected, "on value: {}", val);
+            assert_eq!(actual, expected, "on value: {val}");
         }
     }
 }
diff --git a/juniper/src/integrations/url.rs b/juniper/src/integrations/url.rs
index e3764c6b..6121ac56 100644
--- a/juniper/src/integrations/url.rs
+++ b/juniper/src/integrations/url.rs
@@ -14,8 +14,8 @@ mod url_scalar {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Url, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
-            .and_then(|s| Url::parse(s).map_err(|e| format!("Failed to parse `Url`: {}", e)))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
+            .and_then(|s| Url::parse(s).map_err(|e| format!("Failed to parse `Url`: {e}")))
     }
 }
 
diff --git a/juniper/src/integrations/uuid.rs b/juniper/src/integrations/uuid.rs
index 37f71042..4fed7f5f 100644
--- a/juniper/src/integrations/uuid.rs
+++ b/juniper/src/integrations/uuid.rs
@@ -16,8 +16,8 @@ mod uuid_scalar {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Uuid, String> {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
-            .and_then(|s| Uuid::parse_str(s).map_err(|e| format!("Failed to parse `Uuid`: {}", e)))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
+            .and_then(|s| Uuid::parse_str(s).map_err(|e| format!("Failed to parse `Uuid`: {e}")))
     }
 }
 
diff --git a/juniper/src/introspection/mod.rs b/juniper/src/introspection/mod.rs
index aedd4ef9..e59a492e 100644
--- a/juniper/src/introspection/mod.rs
+++ b/juniper/src/introspection/mod.rs
@@ -5,15 +5,12 @@ pub(crate) const INTROSPECTION_QUERY_WITHOUT_DESCRIPTIONS: &str =
 
 /// The desired GraphQL introspection format for the canonical query
 /// (<https://github.com/graphql/graphql-js/blob/90bd6ff72625173dd39a1f82cfad9336cfad8f65/src/utilities/getIntrospectionQuery.ts#L62>)
+#[derive(Clone, Copy, Debug, Default)]
 pub enum IntrospectionFormat {
     /// The canonical GraphQL introspection query.
+    #[default]
     All,
+
     /// The canonical GraphQL introspection query without descriptions.
     WithoutDescriptions,
 }
-
-impl Default for IntrospectionFormat {
-    fn default() -> Self {
-        IntrospectionFormat::All
-    }
-}
diff --git a/juniper/src/lib.rs b/juniper/src/lib.rs
index e113fcd9..ae753c8e 100644
--- a/juniper/src/lib.rs
+++ b/juniper/src/lib.rs
@@ -6,6 +6,7 @@
 
 // Required for using `juniper_codegen` macros inside this crate to resolve
 // absolute `::juniper` path correctly, without errors.
+extern crate core;
 extern crate self as juniper;
 
 use std::fmt;
@@ -108,10 +109,10 @@ pub enum GraphQLError {
 impl fmt::Display for GraphQLError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            Self::ParseError(e) => write!(f, "{}", e),
+            Self::ParseError(e) => write!(f, "{e}"),
             Self::ValidationError(errs) => {
                 for e in errs {
-                    writeln!(f, "{}", e)?;
+                    writeln!(f, "{e}")?;
                 }
                 Ok(())
             }
diff --git a/juniper/src/macros/graphql_vars.rs b/juniper/src/macros/graphql_vars.rs
index 56bff3b3..5d0f5562 100644
--- a/juniper/src/macros/graphql_vars.rs
+++ b/juniper/src/macros/graphql_vars.rs
@@ -217,37 +217,35 @@ mod tests {
 
         assert_eq!(
             graphql_vars! {"key": 123},
-            vec![("key".to_owned(), IV::scalar(123))]
+            vec![("key".into(), IV::scalar(123))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": "val"},
-            vec![("key".to_owned(), IV::scalar("val"))]
+            vec![("key".into(), IV::scalar("val"))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": 1.23},
-            vec![("key".to_owned(), IV::scalar(1.23))]
+            vec![("key".into(), IV::scalar(1.23))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": 1 + 2},
-            vec![("key".to_owned(), IV::scalar(3))]
-                .into_iter()
-                .collect(),
+            vec![("key".into(), IV::scalar(3))].into_iter().collect(),
         );
         assert_eq!(
             graphql_vars! {"key": false},
-            vec![("key".to_owned(), IV::scalar(false))]
+            vec![("key".into(), IV::scalar(false))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": (val)},
-            vec![("key".to_owned(), IV::scalar(42))]
+            vec![("key".into(), IV::scalar(42))]
                 .into_iter()
                 .collect::<V>(),
         );
@@ -257,13 +255,13 @@ mod tests {
     fn r#enum() {
         assert_eq!(
             graphql_vars! {"key": ENUM},
-            vec![("key".to_owned(), IV::enum_value("ENUM"))]
+            vec![("key".into(), IV::enum_value("ENUM"))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": lowercase},
-            vec![("key".to_owned(), IV::enum_value("lowercase"))]
+            vec![("key".into(), IV::enum_value("lowercase"))]
                 .into_iter()
                 .collect::<V>(),
         );
@@ -273,19 +271,19 @@ mod tests {
     fn variable() {
         assert_eq!(
             graphql_vars! {"key": @var},
-            vec![("key".to_owned(), IV::variable("var"))]
+            vec![("key".into(), IV::variable("var"))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": @array},
-            vec![("key".to_owned(), IV::variable("array"))]
+            vec![("key".into(), IV::variable("array"))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": @object},
-            vec![("key".to_owned(), IV::variable("object"))]
+            vec![("key".into(), IV::variable("object"))]
                 .into_iter()
                 .collect::<V>(),
         );
@@ -297,68 +295,65 @@ mod tests {
 
         assert_eq!(
             graphql_vars! {"key": []},
-            vec![("key".to_owned(), IV::list(vec![]))]
+            vec![("key".into(), IV::list(vec![]))]
                 .into_iter()
                 .collect::<V>(),
         );
 
         assert_eq!(
             graphql_vars! {"key": [null]},
-            vec![("key".to_owned(), IV::list(vec![IV::Null]))]
+            vec![("key".into(), IV::list(vec![IV::Null]))]
                 .into_iter()
                 .collect::<V>(),
         );
 
         assert_eq!(
             graphql_vars! {"key": [1]},
-            vec![("key".to_owned(), IV::list(vec![IV::scalar(1)]))]
+            vec![("key".into(), IV::list(vec![IV::scalar(1)]))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": [1 + 2]},
-            vec![("key".to_owned(), IV::list(vec![IV::scalar(3)]))]
+            vec![("key".into(), IV::list(vec![IV::scalar(3)]))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": [(val)]},
-            vec![("key".to_owned(), IV::list(vec![IV::scalar(42)]))]
+            vec![("key".into(), IV::list(vec![IV::scalar(42)]))]
                 .into_iter()
                 .collect::<V>(),
         );
 
         assert_eq!(
             graphql_vars! {"key": [ENUM]},
-            vec![("key".to_owned(), IV::list(vec![IV::enum_value("ENUM")]))]
+            vec![("key".into(), IV::list(vec![IV::enum_value("ENUM")]))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": [lowercase]},
-            vec![(
-                "key".to_owned(),
-                IV::list(vec![IV::enum_value("lowercase")])
-            )]
-            .into_iter()
-            .collect::<V>(),
+            vec![("key".into(), IV::list(vec![IV::enum_value("lowercase")]))]
+                .into_iter()
+                .collect::<V>(),
         );
 
         assert_eq!(
             graphql_vars! {"key": [@var]},
-            vec![("key".to_owned(), IV::list(vec![IV::variable("var")]))]
+            vec![("key".into(), IV::list(vec![IV::variable("var")]))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": [@array]},
-            vec![("key".to_owned(), IV::list(vec![IV::variable("array")]))]
+            vec![("key".into(), IV::list(vec![IV::variable("array")]))]
                 .into_iter()
                 .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": [@object]},
-            vec![("key".to_owned(), IV::list(vec![IV::variable("object")]))]
+            vec![("key".into(), IV::list(vec![IV::variable("object")]))]
                 .into_iter()
                 .collect::<V>(),
         );
@@ -366,7 +361,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": [1, [2], 3]},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::list(vec![
                     IV::scalar(1),
                     IV::list(vec![IV::scalar(2)]),
@@ -379,7 +374,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": [1, [2 + 3], 3]},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::list(vec![
                     IV::scalar(1),
                     IV::list(vec![IV::scalar(5)]),
@@ -392,7 +387,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": [1, [ENUM], (val)]},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::list(vec![
                     IV::scalar(1),
                     IV::list(vec![IV::enum_value("ENUM")]),
@@ -405,7 +400,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": [1 + 2, [(val)], @val]},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::list(vec![
                     IV::scalar(3),
                     IV::list(vec![IV::scalar(42)]),
@@ -418,7 +413,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": [1, [@val], ENUM]},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::list(vec![
                     IV::scalar(1),
                     IV::list(vec![IV::variable("val")]),
@@ -436,14 +431,14 @@ mod tests {
 
         assert_eq!(
             graphql_vars! {"key": {}},
-            vec![("key".to_owned(), IV::object(IndexMap::<String, _>::new()))]
+            vec![("key".into(), IV::object(IndexMap::<String, _>::new()))]
                 .into_iter()
                 .collect::<V>(),
         );
 
         assert_eq!(
             graphql_vars! {"key": {"key": null}},
-            vec![("key".to_owned(), IV::object(indexmap! {"key" => IV::Null}))]
+            vec![("key".into(), IV::object(indexmap! {"key" => IV::Null}))]
                 .into_iter()
                 .collect::<V>(),
         );
@@ -451,7 +446,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": 123}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::scalar(123)}),
             )]
             .into_iter()
@@ -459,17 +454,14 @@ mod tests {
         );
         assert_eq!(
             graphql_vars! {"key": {"key": 1 + 2}},
-            vec![(
-                "key".to_owned(),
-                IV::object(indexmap! {"key" => IV::scalar(3)}),
-            )]
-            .into_iter()
-            .collect::<V>(),
+            vec![("key".into(), IV::object(indexmap! {"key" => IV::scalar(3)}),)]
+                .into_iter()
+                .collect::<V>(),
         );
         assert_eq!(
             graphql_vars! {"key": {"key": (val)}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::scalar(42)}),
             )]
             .into_iter()
@@ -479,7 +471,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": []}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::list(vec![])}),
             )]
             .into_iter()
@@ -488,7 +480,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": [null]}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::list(vec![IV::Null])}),
             )]
             .into_iter()
@@ -497,7 +489,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": [1]}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::list(vec![IV::scalar(1)])}),
             )]
             .into_iter()
@@ -506,7 +498,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": [1 + 2]}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::list(vec![IV::scalar(3)])}),
             )]
             .into_iter()
@@ -515,7 +507,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": [(val)]}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::list(vec![IV::scalar(42)])}),
             )]
             .into_iter()
@@ -524,7 +516,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": ENUM}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::enum_value("ENUM")}),
             )]
             .into_iter()
@@ -533,7 +525,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": lowercase}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::enum_value("lowercase")}),
             )]
             .into_iter()
@@ -542,7 +534,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": @val}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::variable("val")}),
             )]
             .into_iter()
@@ -551,7 +543,7 @@ mod tests {
         assert_eq!(
             graphql_vars! {"key": {"key": @array}},
             vec![(
-                "key".to_owned(),
+                "key".into(),
                 IV::object(indexmap! {"key" => IV::variable("array")}),
             )]
             .into_iter()
@@ -576,7 +568,7 @@ mod tests {
             },
             vec![
                 (
-                    "inner".to_owned(),
+                    "inner".into(),
                     IV::object(indexmap! {
                         "key1" => IV::scalar(42),
                         "key2" => IV::scalar("val"),
@@ -602,7 +594,7 @@ mod tests {
                         ]),
                     }),
                 ),
-                ("more".to_owned(), IV::variable("var")),
+                ("more".into(), IV::variable("var")),
             ]
             .into_iter()
             .collect::<V>(),
diff --git a/juniper/src/macros/helper/mod.rs b/juniper/src/macros/helper/mod.rs
index f6565e03..e3e31926 100644
--- a/juniper/src/macros/helper/mod.rs
+++ b/juniper/src/macros/helper/mod.rs
@@ -41,8 +41,7 @@ where
 /// [`GraphQLType::name`]: crate::GraphQLType::name
 pub fn err_unnamed_type<S>(name: &str) -> FieldError<S> {
     FieldError::from(format!(
-        "Expected `{}` type to implement `GraphQLType::name`",
-        name,
+        "Expected `{name}` type to implement `GraphQLType::name`",
     ))
 }
 
diff --git a/juniper/src/parser/lexer.rs b/juniper/src/parser/lexer.rs
index be76e6ea..3dd4a0e5 100644
--- a/juniper/src/parser/lexer.rs
+++ b/juniper/src/parser/lexer.rs
@@ -239,7 +239,7 @@ impl<'a> Lexer<'a> {
                 c if escaped => {
                     return Err(Spanning::zero_width(
                         &old_pos,
-                        LexerError::UnknownEscapeSequence(format!("\\{}", c)),
+                        LexerError::UnknownEscapeSequence(format!("\\{c}")),
                     ));
                 }
                 '\\' => escaped = true,
@@ -305,14 +305,14 @@ impl<'a> Lexer<'a> {
         if len != 4 {
             return Err(Spanning::zero_width(
                 start_pos,
-                LexerError::UnknownEscapeSequence("\\u".to_owned() + escape),
+                LexerError::UnknownEscapeSequence(format!("\\u{escape}")),
             ));
         }
 
         let code_point = u32::from_str_radix(escape, 16).map_err(|_| {
             Spanning::zero_width(
                 start_pos,
-                LexerError::UnknownEscapeSequence("\\u".to_owned() + escape),
+                LexerError::UnknownEscapeSequence(format!("\\u{escape}")),
             )
         })?;
 
@@ -485,9 +485,9 @@ impl<'a> Iterator for Lexer<'a> {
 impl<'a> fmt::Display for Token<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Token::Name(name) => write!(f, "{}", name),
+            Token::Name(name) => write!(f, "{name}"),
             Token::Scalar(ScalarToken::Int(s)) | Token::Scalar(ScalarToken::Float(s)) => {
-                write!(f, "{}", s)
+                write!(f, "{s}")
             }
             Token::Scalar(ScalarToken::String(s)) => {
                 write!(f, "\"{}\"", s.replace('\\', "\\\\").replace('"', "\\\""))
@@ -529,15 +529,15 @@ fn is_number_start(c: char) -> bool {
 impl fmt::Display for LexerError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            LexerError::UnknownCharacter(c) => write!(f, "Unknown character \"{}\"", c),
+            LexerError::UnknownCharacter(c) => write!(f, "Unknown character \"{c}\""),
             LexerError::UnterminatedString => write!(f, "Unterminated string literal"),
             LexerError::UnknownCharacterInString(c) => {
-                write!(f, "Unknown character \"{}\" in string literal", c)
+                write!(f, "Unknown character \"{c}\" in string literal")
             }
             LexerError::UnknownEscapeSequence(ref s) => {
-                write!(f, "Unknown escape sequence \"{}\" in string", s)
+                write!(f, "Unknown escape sequence \"{s}\" in string")
             }
-            LexerError::UnexpectedCharacter(c) => write!(f, "Unexpected character \"{}\"", c),
+            LexerError::UnexpectedCharacter(c) => write!(f, "Unexpected character \"{c}\""),
             LexerError::UnexpectedEndOfFile => write!(f, "Unexpected end of input"),
             LexerError::InvalidNumber => write!(f, "Invalid number literal"),
         }
diff --git a/juniper/src/parser/parser.rs b/juniper/src/parser/parser.rs
index 6ee6e758..89ab697b 100644
--- a/juniper/src/parser/parser.rs
+++ b/juniper/src/parser/parser.rs
@@ -25,7 +25,7 @@ pub enum ParseError {
 impl fmt::Display for ParseError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            Self::UnexpectedToken(token) => write!(f, "Unexpected \"{}\"", token),
+            Self::UnexpectedToken(token) => write!(f, "Unexpected \"{token}\""),
             Self::UnexpectedEndOfFile => write!(f, "Unexpected end of input"),
             Self::LexerError(e) => e.fmt(f),
             Self::ExpectedScalarError(e) => e.fmt(f),
@@ -53,7 +53,7 @@ impl ParseError {
         let mut s = String::new();
         // PANIC: Unwrapping is OK here, as it may panic only on allocation
         //        error.
-        write!(s, "{}", token).unwrap();
+        write!(s, "{token}").unwrap();
 
         Self::UnexpectedToken(s)
     }
diff --git a/juniper/src/parser/tests/document.rs b/juniper/src/parser/tests/document.rs
index 55ae6230..65018a3d 100644
--- a/juniper/src/parser/tests/document.rs
+++ b/juniper/src/parser/tests/document.rs
@@ -16,7 +16,7 @@ where
         s,
         &SchemaType::new::<QueryRoot, MutationRoot, SubscriptionRoot>(&(), &(), &()),
     )
-    .expect(&format!("Parse error on input {:#?}", s))
+    .expect(&format!("Parse error on input {s:#?}"))
 }
 
 fn parse_document_error<S: ScalarValue>(s: &str) -> Spanning<ParseError> {
@@ -24,7 +24,7 @@ fn parse_document_error<S: ScalarValue>(s: &str) -> Spanning<ParseError> {
         s,
         &SchemaType::new::<QueryRoot, MutationRoot, SubscriptionRoot>(&(), &(), &()),
     ) {
-        Ok(doc) => panic!("*No* parse error on input {:#?} =>\n{:#?}", s, doc),
+        Ok(doc) => panic!("*No* parse error on input {s:#?} =>\n{doc:#?}"),
         Err(err) => err,
     }
 }
diff --git a/juniper/src/parser/tests/lexer.rs b/juniper/src/parser/tests/lexer.rs
index a08dbfaa..7b295270 100644
--- a/juniper/src/parser/tests/lexer.rs
+++ b/juniper/src/parser/tests/lexer.rs
@@ -13,8 +13,8 @@ fn tokenize_to_vec<'a>(s: &'a str) -> Vec<Spanning<Token<'a>>> {
                     break;
                 }
             }
-            Some(Err(e)) => panic!("Error in input stream: {:#?} for {:#?}", e, s),
-            None => panic!("EOF before EndOfFile token in {:#?}", s),
+            Some(Err(e)) => panic!("Error in input stream: {e:#?} for {s:#?}"),
+            None => panic!("EOF before EndOfFile token in {s:#?}"),
         }
     }
 
@@ -37,13 +37,13 @@ fn tokenize_error(s: &str) -> Spanning<LexerError> {
         match lexer.next() {
             Some(Ok(t)) => {
                 if t.item == Token::EndOfFile {
-                    panic!("Tokenizer did not return error for {:#?}", s);
+                    panic!("Tokenizer did not return error for {s:#?}");
                 }
             }
             Some(Err(e)) => {
                 return e;
             }
-            None => panic!("Tokenizer did not return error for {:#?}", s),
+            None => panic!("Tokenizer did not return error for {s:#?}"),
         }
     }
 }
@@ -196,7 +196,7 @@ fn strings() {
         Spanning::start_end(
             &SourcePosition::new(0, 0, 0),
             &SourcePosition::new(34, 0, 34),
-            Token::Scalar(ScalarToken::String(r#"unicode \u1234\u5678\u90AB\uCDEF"#))
+            Token::Scalar(ScalarToken::String(r#"unicode \u1234\u5678\u90AB\uCDEF"#)),
         )
     );
 }
@@ -207,7 +207,7 @@ fn string_errors() {
         tokenize_error("\""),
         Spanning::zero_width(
             &SourcePosition::new(1, 0, 1),
-            LexerError::UnterminatedString
+            LexerError::UnterminatedString,
         )
     );
 
@@ -215,7 +215,7 @@ fn string_errors() {
         tokenize_error("\"no end quote"),
         Spanning::zero_width(
             &SourcePosition::new(13, 0, 13),
-            LexerError::UnterminatedString
+            LexerError::UnterminatedString,
         )
     );
 
@@ -223,7 +223,7 @@ fn string_errors() {
         tokenize_error("\"contains unescaped \u{0007} control char\""),
         Spanning::zero_width(
             &SourcePosition::new(20, 0, 20),
-            LexerError::UnknownCharacterInString('\u{0007}')
+            LexerError::UnknownCharacterInString('\u{0007}'),
         )
     );
 
@@ -231,7 +231,7 @@ fn string_errors() {
         tokenize_error("\"null-byte is not \u{0000} end of file\""),
         Spanning::zero_width(
             &SourcePosition::new(18, 0, 18),
-            LexerError::UnknownCharacterInString('\u{0000}')
+            LexerError::UnknownCharacterInString('\u{0000}'),
         )
     );
 
@@ -239,7 +239,7 @@ fn string_errors() {
         tokenize_error("\"multi\nline\""),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnterminatedString
+            LexerError::UnterminatedString,
         )
     );
 
@@ -247,7 +247,7 @@ fn string_errors() {
         tokenize_error("\"multi\rline\""),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnterminatedString
+            LexerError::UnterminatedString,
         )
     );
 
@@ -255,7 +255,7 @@ fn string_errors() {
         tokenize_error(r#""bad \z esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\z".to_owned())
+            LexerError::UnknownEscapeSequence("\\z".into()),
         )
     );
 
@@ -263,7 +263,7 @@ fn string_errors() {
         tokenize_error(r#""bad \x esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\x".to_owned())
+            LexerError::UnknownEscapeSequence("\\x".into()),
         )
     );
 
@@ -271,7 +271,7 @@ fn string_errors() {
         tokenize_error(r#""bad \u1 esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\u1".to_owned())
+            LexerError::UnknownEscapeSequence("\\u1".into()),
         )
     );
 
@@ -279,7 +279,7 @@ fn string_errors() {
         tokenize_error(r#""bad \u0XX1 esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\u0XX1".to_owned())
+            LexerError::UnknownEscapeSequence("\\u0XX1".into()),
         )
     );
 
@@ -287,7 +287,7 @@ fn string_errors() {
         tokenize_error(r#""bad \uXXXX esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\uXXXX".to_owned())
+            LexerError::UnknownEscapeSequence("\\uXXXX".into()),
         )
     );
 
@@ -295,7 +295,7 @@ fn string_errors() {
         tokenize_error(r#""bad \uFXXX esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\uFXXX".to_owned())
+            LexerError::UnknownEscapeSequence("\\uFXXX".into()),
         )
     );
 
@@ -303,7 +303,7 @@ fn string_errors() {
         tokenize_error(r#""bad \uXXXF esc""#),
         Spanning::zero_width(
             &SourcePosition::new(6, 0, 6),
-            LexerError::UnknownEscapeSequence("\\uXXXF".to_owned())
+            LexerError::UnknownEscapeSequence("\\uXXXF".into()),
         )
     );
 
@@ -349,9 +349,7 @@ fn numbers() {
             Token::Scalar(ScalarToken::Float(actual)) => {
                 assert!(
                     expected == actual,
-                    "[expected] {} != {} [actual]",
-                    expected,
-                    actual
+                    "[expected] {expected} != {actual} [actual]",
                 );
             }
             _ => assert!(false),
@@ -662,39 +660,32 @@ fn punctuation_error() {
 
 #[test]
 fn display() {
-    assert_eq!(format!("{}", Token::Name("identifier")), "identifier");
-
-    assert_eq!(format!("{}", Token::Scalar(ScalarToken::Int("123"))), "123");
-
-    assert_eq!(
-        format!("{}", Token::Scalar(ScalarToken::Float("4.5"))),
-        "4.5"
-    );
-
-    assert_eq!(
-        format!("{}", Token::Scalar(ScalarToken::String("some string"))),
-        "\"some string\""
-    );
-
-    assert_eq!(
-        format!(
-            "{}",
-            Token::Scalar(ScalarToken::String("string with \\ escape and \" quote"))
+    for (input, expected) in [
+        (Token::Name("identifier"), "identifier"),
+        (Token::Scalar(ScalarToken::Int("123")), "123"),
+        (Token::Scalar(ScalarToken::Float("4.5")), "4.5"),
+        (
+            Token::Scalar(ScalarToken::String("some string")),
+            "\"some string\"",
         ),
-        "\"string with \\\\ escape and \\\" quote\""
-    );
-
-    assert_eq!(format!("{}", Token::ExclamationMark), "!");
-    assert_eq!(format!("{}", Token::Dollar), "$");
-    assert_eq!(format!("{}", Token::ParenOpen), "(");
-    assert_eq!(format!("{}", Token::ParenClose), ")");
-    assert_eq!(format!("{}", Token::BracketOpen), "[");
-    assert_eq!(format!("{}", Token::BracketClose), "]");
-    assert_eq!(format!("{}", Token::CurlyOpen), "{");
-    assert_eq!(format!("{}", Token::CurlyClose), "}");
-    assert_eq!(format!("{}", Token::Ellipsis), "...");
-    assert_eq!(format!("{}", Token::Colon), ":");
-    assert_eq!(format!("{}", Token::Equals), "=");
-    assert_eq!(format!("{}", Token::At), "@");
-    assert_eq!(format!("{}", Token::Pipe), "|");
+        (
+            Token::Scalar(ScalarToken::String("string with \\ escape and \" quote")),
+            "\"string with \\\\ escape and \\\" quote\"",
+        ),
+        (Token::ExclamationMark, "!"),
+        (Token::Dollar, "$"),
+        (Token::ParenOpen, "("),
+        (Token::ParenClose, ")"),
+        (Token::BracketOpen, "["),
+        (Token::BracketClose, "]"),
+        (Token::CurlyOpen, "{"),
+        (Token::CurlyClose, "}"),
+        (Token::Ellipsis, "..."),
+        (Token::Colon, ":"),
+        (Token::Equals, "="),
+        (Token::At, "@"),
+        (Token::Pipe, "|"),
+    ] {
+        assert_eq!(input.to_string(), expected);
+    }
 }
diff --git a/juniper/src/parser/tests/value.rs b/juniper/src/parser/tests/value.rs
index 8dbe78bd..e10a4ab3 100644
--- a/juniper/src/parser/tests/value.rs
+++ b/juniper/src/parser/tests/value.rs
@@ -65,11 +65,11 @@ where
     S: ScalarValue,
 {
     let mut lexer = Lexer::new(s);
-    let mut parser = Parser::new(&mut lexer).expect(&format!("Lexer error on input {:#?}", s));
+    let mut parser = Parser::new(&mut lexer).expect(&format!("Lexer error on input {s:#?}"));
     let schema = SchemaType::new::<Query, EmptyMutation<()>, EmptySubscription<()>>(&(), &(), &());
 
     parse_value_literal(&mut parser, false, &schema, Some(meta))
-        .expect(&format!("Parse error on input {:#?}", s))
+        .expect(&format!("Parse error on input {s:#?}"))
 }
 
 #[test]
diff --git a/juniper/src/schema/meta.rs b/juniper/src/schema/meta.rs
index a7d81a8a..1c11d853 100644
--- a/juniper/src/schema/meta.rs
+++ b/juniper/src/schema/meta.rs
@@ -455,7 +455,7 @@ impl<'a, S> ScalarMeta<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -525,7 +525,7 @@ impl<'a, S> ObjectMeta<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -536,7 +536,7 @@ impl<'a, S> ObjectMeta<'a, S> {
     pub fn interfaces(mut self, interfaces: &[Type<'a>]) -> Self {
         self.interface_names = interfaces
             .iter()
-            .map(|t| t.innermost_name().to_owned())
+            .map(|t| t.innermost_name().into())
             .collect();
         self
     }
@@ -568,7 +568,7 @@ impl<'a, S> EnumMeta<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -598,7 +598,7 @@ impl<'a, S> InterfaceMeta<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -609,7 +609,7 @@ impl<'a, S> InterfaceMeta<'a, S> {
     pub fn interfaces(mut self, interfaces: &[Type<'a>]) -> Self {
         self.interface_names = interfaces
             .iter()
-            .map(|t| t.innermost_name().to_owned())
+            .map(|t| t.innermost_name().into())
             .collect();
         self
     }
@@ -627,10 +627,7 @@ impl<'a> UnionMeta<'a> {
         Self {
             name,
             description: None,
-            of_type_names: of_types
-                .iter()
-                .map(|t| t.innermost_name().to_owned())
-                .collect(),
+            of_type_names: of_types.iter().map(|t| t.innermost_name().into()).collect(),
         }
     }
 
@@ -639,7 +636,7 @@ impl<'a> UnionMeta<'a> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -671,7 +668,7 @@ impl<'a, S> InputObjectMeta<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -687,7 +684,7 @@ impl<'a, S> Field<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -712,7 +709,7 @@ impl<'a, S> Field<'a, S> {
     /// Overwrites any previously set deprecation reason.
     #[must_use]
     pub fn deprecated(mut self, reason: Option<&str>) -> Self {
-        self.deprecation_status = DeprecationStatus::Deprecated(reason.map(ToOwned::to_owned));
+        self.deprecation_status = DeprecationStatus::Deprecated(reason.map(Into::into));
         self
     }
 }
@@ -721,7 +718,7 @@ impl<'a, S> Argument<'a, S> {
     /// Builds a new [`Argument`] of the given [`Type`] with the given `name`.
     pub fn new(name: &str, arg_type: Type<'a>) -> Self {
         Self {
-            name: name.to_owned(),
+            name: name.into(),
             description: None,
             arg_type,
             default_value: None,
@@ -733,7 +730,7 @@ impl<'a, S> Argument<'a, S> {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -751,7 +748,7 @@ impl EnumValue {
     /// Constructs a new [`EnumValue`] with the provided `name`.
     pub fn new(name: &str) -> Self {
         Self {
-            name: name.to_owned(),
+            name: name.into(),
             description: None,
             deprecation_status: DeprecationStatus::Current,
         }
@@ -762,7 +759,7 @@ impl EnumValue {
     /// Overwrites any previously set description.
     #[must_use]
     pub fn description(mut self, description: &str) -> Self {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 
@@ -771,7 +768,7 @@ impl EnumValue {
     /// Overwrites any previously set deprecation reason.
     #[must_use]
     pub fn deprecated(mut self, reason: Option<&str>) -> Self {
-        self.deprecation_status = DeprecationStatus::Deprecated(reason.map(ToOwned::to_owned));
+        self.deprecation_status = DeprecationStatus::Deprecated(reason.map(Into::into));
         self
     }
 }
diff --git a/juniper/src/schema/model.rs b/juniper/src/schema/model.rs
index 5544fbbd..e7cba411 100644
--- a/juniper/src/schema/model.rs
+++ b/juniper/src/schema/model.rs
@@ -167,8 +167,7 @@ where
     /// [GraphQL Schema Language](https://graphql.org/learn/schema/#type-language)
     /// format.
     pub fn as_schema_language(&self) -> String {
-        let doc = self.as_parser_document();
-        format!("{}", doc)
+        self.as_parser_document().to_string()
     }
 
     #[cfg(feature = "graphql-parser")]
@@ -210,17 +209,14 @@ impl<'a, S> SchemaType<'a, S> {
 
         registry.get_type::<SchemaType<S>>(&());
 
-        directives.insert("skip".to_owned(), DirectiveType::new_skip(&mut registry));
+        directives.insert("skip".into(), DirectiveType::new_skip(&mut registry));
+        directives.insert("include".into(), DirectiveType::new_include(&mut registry));
         directives.insert(
-            "include".to_owned(),
-            DirectiveType::new_include(&mut registry),
-        );
-        directives.insert(
-            "deprecated".to_owned(),
+            "deprecated".into(),
             DirectiveType::new_deprecated(&mut registry),
         );
         directives.insert(
-            "specifiedBy".to_owned(),
+            "specifiedBy".into(),
             DirectiveType::new_specified_by(&mut registry),
         );
 
@@ -243,7 +239,7 @@ impl<'a, S> SchemaType<'a, S> {
 
         for meta_type in registry.types.values() {
             if let MetaType::Placeholder(PlaceholderMeta { ref of_type }) = *meta_type {
-                panic!("Type {:?} is still a placeholder type", of_type);
+                panic!("Type {of_type:?} is still a placeholder type");
             }
         }
         SchemaType {
@@ -508,9 +504,9 @@ where
         locations: &[DirectiveLocation],
         arguments: &[Argument<'a, S>],
         is_repeatable: bool,
-    ) -> DirectiveType<'a, S> {
-        DirectiveType {
-            name: name.to_owned(),
+    ) -> Self {
+        Self {
+            name: name.into(),
             description: None,
             locations: locations.to_vec(),
             arguments: arguments.to_vec(),
@@ -578,7 +574,7 @@ where
     }
 
     pub fn description(mut self, description: &str) -> DirectiveType<'a, S> {
-        self.description = Some(description.to_owned());
+        self.description = Some(description.into());
         self
     }
 }
@@ -605,8 +601,8 @@ impl<'a, S> fmt::Display for TypeType<'a, S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             Self::Concrete(t) => f.write_str(t.name().unwrap()),
-            Self::List(i, _) => write!(f, "[{}]", i),
-            Self::NonNull(i) => write!(f, "{}!", i),
+            Self::List(i, _) => write!(f, "[{i}]"),
+            Self::NonNull(i) => write!(f, "{i}!"),
         }
     }
 }
@@ -644,10 +640,7 @@ mod test {
             "#,
             )
             .unwrap();
-            assert_eq!(
-                format!("{}", ast),
-                format!("{}", schema.as_parser_document()),
-            );
+            assert_eq!(ast.to_string(), schema.as_parser_document().to_string());
         }
     }
 
@@ -691,10 +684,10 @@ mod test {
                 }
                 /// This is whatever's description.
                 fn whatever() -> String {
-                    "foo".to_string()
+                    "foo".into()
                 }
                 fn arr(stuff: Vec<Coordinate>) -> Option<&'static str> {
-                    (!stuff.is_empty()).then(|| "stuff")
+                    (!stuff.is_empty()).then_some("stuff")
                 }
                 fn fruit() -> Fruit {
                     Fruit::Apple
@@ -754,7 +747,7 @@ mod test {
             "#,
             )
             .unwrap();
-            assert_eq!(format!("{}", ast), schema.as_schema_language());
+            assert_eq!(ast.to_string(), schema.as_schema_language());
         }
     }
 }
diff --git a/juniper/src/schema/schema.rs b/juniper/src/schema/schema.rs
index 09f10bbd..bf48ea37 100644
--- a/juniper/src/schema/schema.rs
+++ b/juniper/src/schema/schema.rs
@@ -288,16 +288,16 @@ impl<'a, S: ScalarValue + 'a> TypeType<'a, S> {
                     .iter()
                     .filter_map(|&ct| {
                         if let MetaType::Object(ObjectMeta {
-                            ref name,
-                            ref interface_names,
+                            name,
+                            interface_names,
                             ..
-                        }) = *ct
+                        }) = ct
                         {
-                            if interface_names.contains(&iface_name.to_string()) {
-                                context.type_by_name(name)
-                            } else {
-                                None
-                            }
+                            interface_names
+                                .iter()
+                                .any(|name| name == iface_name)
+                                .then(|| context.type_by_name(name))
+                                .flatten()
                         } else {
                             None
                         }
diff --git a/juniper/src/schema/translate/graphql_parser.rs b/juniper/src/schema/translate/graphql_parser.rs
index 5532c0fb..6051965b 100644
--- a/juniper/src/schema/translate/graphql_parser.rs
+++ b/juniper/src/schema/translate/graphql_parser.rs
@@ -285,15 +285,11 @@ where
         DeprecationStatus::Current => None,
         DeprecationStatus::Deprecated(reason) => Some(ExternalDirective {
             position: Pos::default(),
-            name: From::from("deprecated"),
-            arguments: if let Some(reason) = reason {
-                vec![(
-                    From::from("reason"),
-                    ExternalValue::String(reason.to_string()),
-                )]
-            } else {
-                vec![]
-            },
+            name: "deprecated".into(),
+            arguments: reason
+                .as_ref()
+                .map(|rsn| vec![(From::from("reason"), ExternalValue::String(rsn.into()))])
+                .unwrap_or_default(),
         }),
     }
 }
diff --git a/juniper/src/tests/fixtures/starwars/schema.rs b/juniper/src/tests/fixtures/starwars/schema.rs
index d9c795de..d89af6bc 100644
--- a/juniper/src/tests/fixtures/starwars/schema.rs
+++ b/juniper/src/tests/fixtures/starwars/schema.rs
@@ -93,12 +93,12 @@ impl Human {
         home_planet: Option<&str>,
     ) -> Self {
         Self {
-            id: id.to_owned(),
-            name: name.to_owned(),
-            friend_ids: friend_ids.iter().copied().map(ToOwned::to_owned).collect(),
+            id: id.into(),
+            name: name.into(),
+            friend_ids: friend_ids.iter().copied().map(Into::into).collect(),
             appears_in: appears_in.to_vec(),
-            secret_backstory: secret_backstory.map(ToOwned::to_owned),
-            home_planet: home_planet.map(|p| p.to_owned()),
+            secret_backstory: secret_backstory.map(Into::into),
+            home_planet: home_planet.map(Into::into),
         }
     }
 }
@@ -153,12 +153,12 @@ impl Droid {
         primary_function: Option<&str>,
     ) -> Self {
         Self {
-            id: id.to_owned(),
-            name: name.to_owned(),
-            friend_ids: friend_ids.iter().copied().map(ToOwned::to_owned).collect(),
+            id: id.into(),
+            name: name.into(),
+            friend_ids: friend_ids.iter().copied().map(Into::into).collect(),
             appears_in: appears_in.to_vec(),
-            secret_backstory: secret_backstory.map(ToOwned::to_owned),
-            primary_function: primary_function.map(ToOwned::to_owned),
+            secret_backstory: secret_backstory.map(Into::into),
+            primary_function: primary_function.map(Into::into),
         }
     }
 }
@@ -192,7 +192,7 @@ impl Droid {
     }
 }
 
-#[derive(Default, Clone)]
+#[derive(Clone, Default)]
 pub struct Database {
     humans: HashMap<String, Human>,
     droids: HashMap<String, Droid>,
@@ -206,7 +206,7 @@ impl Database {
         let mut droids = HashMap::new();
 
         humans.insert(
-            "1000".to_owned(),
+            "1000".into(),
             Human::new(
                 "1000",
                 "Luke Skywalker",
@@ -218,7 +218,7 @@ impl Database {
         );
 
         humans.insert(
-            "1001".to_owned(),
+            "1001".into(),
             Human::new(
                 "1001",
                 "Darth Vader",
@@ -230,7 +230,7 @@ impl Database {
         );
 
         humans.insert(
-            "1002".to_owned(),
+            "1002".into(),
             Human::new(
                 "1002",
                 "Han Solo",
@@ -242,7 +242,7 @@ impl Database {
         );
 
         humans.insert(
-            "1003".to_owned(),
+            "1003".into(),
             Human::new(
                 "1003",
                 "Leia Organa",
@@ -254,7 +254,7 @@ impl Database {
         );
 
         humans.insert(
-            "1004".to_owned(),
+            "1004".into(),
             Human::new(
                 "1004",
                 "Wilhuff Tarkin",
@@ -266,7 +266,7 @@ impl Database {
         );
 
         droids.insert(
-            "2000".to_owned(),
+            "2000".into(),
             Droid::new(
                 "2000",
                 "C-3PO",
@@ -278,7 +278,7 @@ impl Database {
         );
 
         droids.insert(
-            "2001".to_owned(),
+            "2001".into(),
             Droid::new(
                 "2001",
                 "R2-D2",
diff --git a/juniper/src/tests/subscriptions.rs b/juniper/src/tests/subscriptions.rs
index 6ba01a76..8c73486b 100644
--- a/juniper/src/tests/subscriptions.rs
+++ b/juniper/src/tests/subscriptions.rs
@@ -1,4 +1,4 @@
-use std::{iter, iter::FromIterator as _, pin::Pin};
+use std::{iter, pin::Pin};
 
 use futures::{stream, StreamExt as _};
 
@@ -48,9 +48,9 @@ impl MySubscription {
     async fn async_human() -> HumanStream {
         Box::pin(stream::once(async {
             Human {
-                id: "stream id".to_string(),
-                name: "stream name".to_string(),
-                home_planet: "stream home planet".to_string(),
+                id: "stream id".into(),
+                name: "stream name".into(),
+                home_planet: "stream home planet".into(),
             }
         }))
     }
@@ -78,7 +78,7 @@ impl MySubscription {
             Human {
                 id,
                 name,
-                home_planet: "default home planet".to_string(),
+                home_planet: "default home planet".into(),
             }
         }))
     }
@@ -154,10 +154,10 @@ fn returns_requested_object() {
             id
             name
         }
-    }"#
-    .to_string();
+    }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(
@@ -182,10 +182,9 @@ fn returns_error() {
             id
             name
         }
-    }"#
-    .to_string();
+    }"#;
 
-    let response = create_and_execute(query);
+    let response = create_and_execute(query.into());
 
     assert!(response.is_err());
 
@@ -206,10 +205,10 @@ fn can_access_context() {
             humanWithContext {
                 id
               }
-        }"#
-    .to_string();
+        }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(iter::from_fn(
@@ -234,10 +233,10 @@ fn resolves_typed_inline_fragments() {
                   id
                 }
              }
-           }"#
-    .to_string();
+           }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(iter::from_fn(
@@ -262,10 +261,10 @@ fn resolves_nontyped_inline_fragments() {
                   id
                 }
              }
-           }"#
-    .to_string();
+           }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(iter::from_fn(
@@ -289,10 +288,10 @@ fn can_access_arguments() {
                 id
                 name
               }
-        }"#
-    .to_string();
+        }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(iter::from_fn(
@@ -317,10 +316,10 @@ fn type_alias() {
             id
             name
         }
-    }"#
-    .to_string();
+    }"#;
 
-    let (names, collected_values) = create_and_execute(query).expect("Got error from stream");
+    let (names, collected_values) =
+        create_and_execute(query.into()).expect("Got error from stream");
 
     let mut iterator_count = 0;
     let expected_values = vec![vec![Ok(Value::Object(Object::from_iter(iter::from_fn(
diff --git a/juniper/src/tests/type_info_tests.rs b/juniper/src/tests/type_info_tests.rs
index 61e7662b..6b43a7ef 100644
--- a/juniper/src/tests/type_info_tests.rs
+++ b/juniper/src/tests/type_info_tests.rs
@@ -75,15 +75,15 @@ fn test_node() {
             baz
         }"#;
     let node_info = NodeTypeInfo {
-        name: "MyNode".to_string(),
-        attribute_names: vec!["foo".to_string(), "bar".to_string(), "baz".to_string()],
+        name: "MyNode".into(),
+        attribute_names: vec!["foo".into(), "bar".into(), "baz".into()],
     };
     let mut node = Node {
         attributes: IndexMap::new(),
     };
-    node.attributes.insert("foo".to_string(), "1".to_string());
-    node.attributes.insert("bar".to_string(), "2".to_string());
-    node.attributes.insert("baz".to_string(), "3".to_string());
+    node.attributes.insert("foo".into(), "1".into());
+    node.attributes.insert("bar".into(), "2".into());
+    node.attributes.insert("baz".into(), "3".into());
     let schema: RootNode<_, _, _> = RootNode::new_with_info(
         node,
         EmptyMutation::new(),
diff --git a/juniper/src/types/async_await.rs b/juniper/src/types/async_await.rs
index ebb948ca..562bff7c 100644
--- a/juniper/src/types/async_await.rs
+++ b/juniper/src/types/async_await.rs
@@ -226,7 +226,7 @@ where
                     panic!(
                         "Field {} not found on type {:?}",
                         f.name.item,
-                        meta_type.name()
+                        meta_type.name(),
                     )
                 });
 
diff --git a/juniper/src/types/base.rs b/juniper/src/types/base.rs
index b46315b7..9d54fee0 100644
--- a/juniper/src/types/base.rs
+++ b/juniper/src/types/base.rs
@@ -377,7 +377,7 @@ where
 ///             // schema in `meta()` above, or a validation failed because of a this library bug.
 ///             //
 ///             // In either of those two cases, the only reasonable way out is to panic the thread.
-///             _ => panic!("Field {} not found on type User", field_name),
+///             _ => panic!("Field {field_name} not found on type User"),
 ///         }
 ///     }
 /// }
@@ -452,7 +452,7 @@ where
                     panic!(
                         "Field {} not found on type {:?}",
                         f.name.item,
-                        meta_type.name()
+                        meta_type.name(),
                     )
                 });
 
diff --git a/juniper/src/types/containers.rs b/juniper/src/types/containers.rs
index ab5383a4..108f0e02 100644
--- a/juniper/src/types/containers.rs
+++ b/juniper/src/types/containers.rs
@@ -522,12 +522,11 @@ where
     fn into_field_error(self) -> FieldError<S> {
         const ERROR_PREFIX: &str = "Failed to convert into exact-size array";
         match self {
-            Self::Null => format!("{}: Value cannot be `null`", ERROR_PREFIX).into(),
-            Self::WrongCount { actual, expected } => format!(
-                "{}: wrong elements count: {} instead of {}",
-                ERROR_PREFIX, actual, expected
-            )
-            .into(),
+            Self::Null => format!("{ERROR_PREFIX}: Value cannot be `null`").into(),
+            Self::WrongCount { actual, expected } => {
+                format!("{ERROR_PREFIX}: wrong elements count: {actual} instead of {expected}",)
+                    .into()
+            }
             Self::Item(s) => s.into_field_error(),
         }
     }
diff --git a/juniper/src/types/name.rs b/juniper/src/types/name.rs
index eae555d9..fbf5304d 100644
--- a/juniper/src/types/name.rs
+++ b/juniper/src/types/name.rs
@@ -50,11 +50,10 @@ impl FromStr for Name {
     type Err = NameParseError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         if Name::is_valid(s) {
-            Ok(Name(s.to_string()))
+            Ok(Name(s.into()))
         } else {
             Err(NameParseError(format!(
-                "Names must match /^[_a-zA-Z][_a-zA-Z0-9]*$/ but \"{}\" does not",
-                s
+                "Names must match /^[_a-zA-Z][_a-zA-Z0-9]*$/ but \"{s}\" does not",
             )))
         }
     }
diff --git a/juniper/src/types/nullable.rs b/juniper/src/types/nullable.rs
index 7e8d01cc..20f16708 100644
--- a/juniper/src/types/nullable.rs
+++ b/juniper/src/types/nullable.rs
@@ -32,12 +32,16 @@ use crate::{
 pub enum Nullable<T> {
     /// No value
     ImplicitNull,
+
     /// No value, explicitly specified to be null
     ExplicitNull,
+
     /// Some value `T`
     Some(T),
 }
 
+// Implemented manually to omit redundant `T: Default` trait bound, imposed by
+// `#[derive(Default)]`.
 impl<T> Default for Nullable<T> {
     fn default() -> Self {
         Self::ImplicitNull
diff --git a/juniper/src/types/scalars.rs b/juniper/src/types/scalars.rs
index 3f3422e3..54efa392 100644
--- a/juniper/src/types/scalars.rs
+++ b/juniper/src/types/scalars.rs
@@ -37,7 +37,7 @@ impl ID {
             .map(str::to_owned)
             .or_else(|| v.as_int_value().as_ref().map(ToString::to_string))
             .map(Self)
-            .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
     }
 }
 
@@ -81,7 +81,7 @@ mod impl_string_scalar {
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<String, String> {
         v.as_string_value()
             .map(str::to_owned)
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
     }
 
     pub(super) fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -120,7 +120,7 @@ mod impl_string_scalar {
                         }
                         Some(s) => {
                             return Err(ParseError::LexerError(LexerError::UnknownEscapeSequence(
-                                format!("\\{}", s),
+                                format!("\\{s}"),
                             )))
                         }
                         None => return Err(ParseError::LexerError(LexerError::UnterminatedString)),
@@ -149,19 +149,16 @@ where
         .and_then(|c1| {
             char_iter
                 .next()
-                .map(|c2| format!("{}{}", c1, c2))
+                .map(|c2| format!("{c1}{c2}"))
                 .ok_or_else(|| {
-                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!("\\u{}", c1)))
+                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!("\\u{c1}")))
                 })
         })
         .and_then(|mut s| {
             char_iter
                 .next()
                 .ok_or_else(|| {
-                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!(
-                        "\\u{}",
-                        s.clone()
-                    )))
+                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!("\\u{s}")))
                 })
                 .map(|c2| {
                     s.push(c2);
@@ -172,10 +169,7 @@ where
             char_iter
                 .next()
                 .ok_or_else(|| {
-                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!(
-                        "\\u{}",
-                        s.clone()
-                    )))
+                    ParseError::LexerError(LexerError::UnknownEscapeSequence(format!("\\u{s}")))
                 })
                 .map(|c2| {
                     s.push(c2);
@@ -184,14 +178,12 @@ where
         })?;
     let code_point = u32::from_str_radix(&escaped_code_point, 16).map_err(|_| {
         ParseError::LexerError(LexerError::UnknownEscapeSequence(format!(
-            "\\u{}",
-            escaped_code_point
+            "\\u{escaped_code_point}",
         )))
     })?;
     char::from_u32(code_point).ok_or_else(|| {
         ParseError::LexerError(LexerError::UnknownEscapeSequence(format!(
-            "\\u{}",
-            escaped_code_point
+            "\\u{escaped_code_point}",
         )))
     })
 }
@@ -282,7 +274,7 @@ mod impl_boolean_scalar {
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Boolean, String> {
         v.as_scalar_value()
             .and_then(ScalarValue::as_bool)
-            .ok_or_else(|| format!("Expected `Boolean`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Boolean`, found: {v}"))
     }
 
     pub(super) fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -303,7 +295,7 @@ mod impl_int_scalar {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Int, String> {
         v.as_int_value()
-            .ok_or_else(|| format!("Expected `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Int`, found: {v}"))
     }
 
     pub(super) fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -329,7 +321,7 @@ mod impl_float_scalar {
 
     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Float, String> {
         v.as_float_value()
-            .ok_or_else(|| format!("Expected `Float`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Float`, found: {v}"))
     }
 
     pub(super) fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -401,8 +393,9 @@ where
 {
 }
 
+// Implemented manually to omit redundant `T: Default` trait bound, imposed by
+// `#[derive(Default)]`.
 impl<T> Default for EmptyMutation<T> {
-    #[inline]
     fn default() -> Self {
         Self::new()
     }
@@ -461,8 +454,9 @@ where
 {
 }
 
+// Implemented manually to omit redundant `T: Default` trait bound, imposed by
+// `#[derive(Default)]`.
 impl<T> Default for EmptySubscription<T> {
-    #[inline]
     fn default() -> Self {
         Self::new()
     }
@@ -499,8 +493,8 @@ mod tests {
 
     #[test]
     fn test_id_display() {
-        let id = ID(String::from("foo"));
-        assert_eq!(format!("{}", id), "foo");
+        let id = ID("foo".into());
+        assert_eq!(id.to_string(), "foo");
     }
 
     #[test]
@@ -508,7 +502,7 @@ mod tests {
         fn parse_string(s: &str, expected: &str) {
             let s =
                 <String as ParseScalarValue<DefaultScalarValue>>::from_str(ScalarToken::String(s));
-            assert!(s.is_ok(), "A parsing error occurred: {:?}", s);
+            assert!(s.is_ok(), "A parsing error occurred: {s:?}");
             let s: Option<String> = s.unwrap().into();
             assert!(s.is_some(), "No string returned");
             assert_eq!(s.unwrap(), expected);
@@ -527,7 +521,7 @@ mod tests {
 
     #[test]
     fn parse_f64_from_int() {
-        for (v, expected) in &[
+        for (v, expected) in [
             ("0", 0),
             ("128", 128),
             ("1601942400", 1601942400),
@@ -538,14 +532,14 @@ mod tests {
             assert!(n.is_ok(), "A parsing error occurred: {:?}", n.unwrap_err());
 
             let n: Option<f64> = n.unwrap().into();
-            assert!(n.is_some(), "No f64 returned");
-            assert_eq!(n.unwrap(), f64::from(*expected));
+            assert!(n.is_some(), "No `f64` returned");
+            assert_eq!(n.unwrap(), f64::from(expected));
         }
     }
 
     #[test]
     fn parse_f64_from_float() {
-        for (v, expected) in &[
+        for (v, expected) in [
             ("0.", 0.),
             ("1.2", 1.2),
             ("1601942400.", 1601942400.),
@@ -556,8 +550,8 @@ mod tests {
             assert!(n.is_ok(), "A parsing error occurred: {:?}", n.unwrap_err());
 
             let n: Option<f64> = n.unwrap().into();
-            assert!(n.is_some(), "No f64 returned");
-            assert_eq!(n.unwrap(), *expected);
+            assert!(n.is_some(), "No `f64` returned");
+            assert_eq!(n.unwrap(), expected);
         }
     }
 
diff --git a/juniper/src/validation/context.rs b/juniper/src/validation/context.rs
index d90e7362..c96c0491 100644
--- a/juniper/src/validation/context.rs
+++ b/juniper/src/validation/context.rs
@@ -30,9 +30,9 @@ pub struct ValidatorContext<'a, S: Debug + 'a> {
 
 impl RuleError {
     #[doc(hidden)]
-    pub fn new(message: &str, locations: &[SourcePosition]) -> RuleError {
-        RuleError {
-            message: message.to_owned(),
+    pub fn new(message: &str, locations: &[SourcePosition]) -> Self {
+        Self {
+            message: message.into(),
             locations: locations.to_vec(),
         }
     }
@@ -53,14 +53,15 @@ impl RuleError {
 
 impl fmt::Display for RuleError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        // this is fine since all `RuleError`s should have at least one source position
+        // This is fine since all `RuleError`s should have at least one source
+        // position.
         let locations = self
             .locations
             .iter()
-            .map(|location| format!("{}", location))
+            .map(ToString::to_string)
             .collect::<Vec<_>>()
             .join(", ");
-        write!(f, "{}. At {}", self.message, locations)
+        write!(f, "{}. At {locations}", self.message)
     }
 }
 
diff --git a/juniper/src/validation/input_value.rs b/juniper/src/validation/input_value.rs
index b6238172..780a0ab3 100644
--- a/juniper/src/validation/input_value.rs
+++ b/juniper/src/validation/input_value.rs
@@ -99,7 +99,7 @@ where
                     var_name,
                     var_pos,
                     &path,
-                    &format!(r#"Expected "{}", found null"#, meta_type),
+                    format!(r#"Expected "{meta_type}", found null"#),
                 ));
             } else {
                 errors.append(&mut unify_value(
@@ -121,10 +121,10 @@ where
                                 var_name,
                                 var_pos,
                                 &path,
-                                &format!(
-                                    "Expected list of {} elements, found {} elements",
-                                    expected,
-                                    l.len()
+                                format!(
+                                    "Expected list of {expected} elements, \
+                                     found {} elements",
+                                    l.len(),
                                 ),
                             ));
                         }
@@ -168,11 +168,11 @@ where
                                 var_name,
                                 var_pos,
                                 &path,
-                                &format!(
-                                    "Expected input of type `{}`. Got: `{}`. \
+                                format!(
+                                    "Expected input of type `{}`. \
+                                     Got: `{value}`. \
                                      Details: {}",
                                     iom.name,
-                                    value,
                                     e.message(),
                                 ),
                             ));
@@ -205,10 +205,9 @@ where
             var_name,
             var_pos,
             path,
-            &format!(
-                "Expected input scalar `{}`. Got: `{}`. Details: {}",
+            format!(
+                "Expected input scalar `{}`. Got: `{value}`. Details: {}",
                 meta.name,
-                value,
                 e.message(),
             ),
         )];
@@ -219,13 +218,13 @@ where
             var_name,
             var_pos,
             path,
-            &format!(r#"Expected "{}", found list"#, meta.name),
+            format!(r#"Expected "{}", found list"#, meta.name),
         )),
         InputValue::Object(_) => errors.push(unification_error(
             var_name,
             var_pos,
             path,
-            &format!(r#"Expected "{}", found object"#, meta.name),
+            format!(r#"Expected "{}", found object"#, meta.name),
         )),
         _ => (),
     }
@@ -244,27 +243,27 @@ where
 {
     let mut errors: Vec<RuleError> = vec![];
 
-    match *value {
+    match value {
         // TODO: avoid this bad duplicate as_str() call. (value system refactor)
-        InputValue::Scalar(ref scalar) if scalar.as_str().is_some() => {
+        InputValue::Scalar(scalar) if scalar.as_str().is_some() => {
             if let Some(name) = scalar.as_str() {
                 if !meta.values.iter().any(|ev| ev.name == *name) {
                     errors.push(unification_error(
                         var_name,
                         var_pos,
                         path,
-                        &format!(r#"Invalid value for enum "{}""#, meta.name),
+                        format!(r#"Invalid value for enum "{}""#, meta.name),
                     ))
                 }
             }
         }
-        InputValue::Enum(ref name) => {
+        InputValue::Enum(name) => {
             if !meta.values.iter().any(|ev| &ev.name == name) {
                 errors.push(unification_error(
                     var_name,
                     var_pos,
                     path,
-                    &format!(r#"Invalid value for enum "{}""#, meta.name),
+                    format!(r#"Invalid value for enum "{}""#, meta.name),
                 ))
             }
         }
@@ -272,7 +271,7 @@ where
             var_name,
             var_pos,
             path,
-            &format!(r#"Expected "{}", found not a string or enum"#, meta.name),
+            format!(r#"Expected "{}", found not a string or enum"#, meta.name),
         )),
     }
     errors
@@ -318,7 +317,7 @@ where
                     var_name,
                     var_pos,
                     &Path::ObjectField(&input_field.name, path),
-                    &format!(r#"Expected "{}", found null"#, input_field.arg_type),
+                    format!(r#"Expected "{}", found null"#, input_field.arg_type),
                 ));
             }
         }
@@ -336,7 +335,7 @@ where
             var_name,
             var_pos,
             path,
-            &format!(r#"Expected "{}", found not an object"#, meta.name),
+            format!(r#"Expected "{}", found not an object"#, meta.name),
         ));
     }
     errors
@@ -349,17 +348,14 @@ where
     v.map_or(true, InputValue::is_null)
 }
 
-fn unification_error<'a>(
-    var_name: &str,
+fn unification_error(
+    var_name: impl fmt::Display,
     var_pos: &SourcePosition,
-    path: &Path<'a>,
-    message: &str,
+    path: &Path<'_>,
+    message: impl fmt::Display,
 ) -> RuleError {
     RuleError::new(
-        &format!(
-            r#"Variable "${}" got invalid value. {}{}."#,
-            var_name, path, message,
-        ),
+        &format!(r#"Variable "${var_name}" got invalid value. {path}{message}."#),
         &[*var_pos],
     )
 }
@@ -368,8 +364,8 @@ impl<'a> fmt::Display for Path<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             Path::Root => write!(f, ""),
-            Path::ArrayElement(idx, prev) => write!(f, "{}In element #{}: ", prev, idx),
-            Path::ObjectField(name, prev) => write!(f, r#"{}In field "{}": "#, prev, name),
+            Path::ArrayElement(idx, prev) => write!(f, "{prev}In element #{idx}: "),
+            Path::ObjectField(name, prev) => write!(f, r#"{prev}In field "{name}": "#),
         }
     }
 }
diff --git a/juniper/src/validation/rules/arguments_of_correct_type.rs b/juniper/src/validation/rules/arguments_of_correct_type.rs
index 495ca4f7..8230267d 100644
--- a/juniper/src/validation/rules/arguments_of_correct_type.rs
+++ b/juniper/src/validation/rules/arguments_of_correct_type.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{
     ast::{Directive, Field, InputValue},
     parser::Spanning,
@@ -6,13 +8,12 @@ use crate::{
     validation::{ValidatorContext, Visitor},
     value::ScalarValue,
 };
-use std::fmt::Debug;
 
-pub struct ArgumentsOfCorrectType<'a, S: Debug + 'a> {
+pub struct ArgumentsOfCorrectType<'a, S: fmt::Debug + 'a> {
     current_args: Option<&'a Vec<Argument<'a, S>>>,
 }
 
-pub fn factory<'a, S: Debug>() -> ArgumentsOfCorrectType<'a, S> {
+pub fn factory<'a, S: fmt::Debug>() -> ArgumentsOfCorrectType<'a, S> {
     ArgumentsOfCorrectType { current_args: None }
 }
 
@@ -59,7 +60,7 @@ where
 
             if !is_valid_literal_value(ctx.schema, &meta_type, &arg_value.item) {
                 ctx.report_error(
-                    &error_message(arg_name.item, &format!("{}", argument_meta.arg_type)),
+                    &error_message(arg_name.item, &argument_meta.arg_type),
                     &[arg_value.start],
                 );
             }
@@ -67,11 +68,8 @@ where
     }
 }
 
-fn error_message(arg_name: &str, type_name: &str) -> String {
-    format!(
-        "Invalid value for argument \"{}\", expected type \"{}\"",
-        arg_name, type_name
-    )
+fn error_message(arg_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
+    format!("Invalid value for argument \"{arg_name}\", expected type \"{type_name}\"",)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/default_values_of_correct_type.rs b/juniper/src/validation/rules/default_values_of_correct_type.rs
index 8ef4f98b..2d15f854 100644
--- a/juniper/src/validation/rules/default_values_of_correct_type.rs
+++ b/juniper/src/validation/rules/default_values_of_correct_type.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{
     ast::VariableDefinition,
     parser::Spanning,
@@ -29,7 +31,7 @@ where
         {
             if var_def.var_type.item.is_non_null() {
                 ctx.report_error(
-                    &non_null_error_message(var_name.item, &format!("{}", var_def.var_type.item)),
+                    &non_null_error_message(var_name.item, &var_def.var_type.item),
                     &[*start],
                 )
             } else {
@@ -37,7 +39,7 @@ where
 
                 if !is_valid_literal_value(ctx.schema, &meta_type, var_value) {
                     ctx.report_error(
-                        &type_error_message(var_name.item, &format!("{}", var_def.var_type.item)),
+                        &type_error_message(var_name.item, &var_def.var_type.item),
                         &[*start],
                     );
                 }
@@ -46,17 +48,14 @@ where
     }
 }
 
-fn type_error_message(arg_name: &str, type_name: &str) -> String {
-    format!(
-        "Invalid default value for argument \"{}\", expected type \"{}\"",
-        arg_name, type_name
-    )
+fn type_error_message(arg_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
+    format!("Invalid default value for argument \"{arg_name}\", expected type \"{type_name}\"")
 }
 
-fn non_null_error_message(arg_name: &str, type_name: &str) -> String {
+fn non_null_error_message(arg_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
     format!(
-        "Argument \"{}\" has type \"{}\" and is not nullable, so it can't have a default value",
-        arg_name, type_name
+        "Argument \"{arg_name}\" has type \"{type_name}\" and is not nullable, \
+         so it can't have a default value",
     )
 }
 
diff --git a/juniper/src/validation/rules/fields_on_correct_type.rs b/juniper/src/validation/rules/fields_on_correct_type.rs
index ad90cb25..b195df45 100644
--- a/juniper/src/validation/rules/fields_on_correct_type.rs
+++ b/juniper/src/validation/rules/fields_on_correct_type.rs
@@ -69,7 +69,7 @@ where
 }
 
 fn error_message(field: &str, type_name: &str) -> String {
-    format!(r#"Unknown field "{}" on type "{}""#, field, type_name)
+    format!(r#"Unknown field "{field}" on type "{type_name}""#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/fragments_on_composite_types.rs b/juniper/src/validation/rules/fragments_on_composite_types.rs
index 1d2ca75b..927f46de 100644
--- a/juniper/src/validation/rules/fragments_on_composite_types.rs
+++ b/juniper/src/validation/rules/fragments_on_composite_types.rs
@@ -59,15 +59,9 @@ where
 
 fn error_message(fragment_name: Option<&str>, on_type: &str) -> String {
     if let Some(name) = fragment_name {
-        format!(
-            r#"Fragment "{}" cannot condition non composite type "{}"#,
-            name, on_type
-        )
+        format!(r#"Fragment "{name}" cannot condition non composite type "{on_type}"#)
     } else {
-        format!(
-            r#"Fragment cannot condition on non composite type "{}""#,
-            on_type
-        )
+        format!(r#"Fragment cannot condition on non composite type "{on_type}""#)
     }
 }
 
diff --git a/juniper/src/validation/rules/known_argument_names.rs b/juniper/src/validation/rules/known_argument_names.rs
index 6e579977..d652caf3 100644
--- a/juniper/src/validation/rules/known_argument_names.rs
+++ b/juniper/src/validation/rules/known_argument_names.rs
@@ -91,17 +91,11 @@ where
 }
 
 fn field_error_message(arg_name: &str, field_name: &str, type_name: &str) -> String {
-    format!(
-        r#"Unknown argument "{}" on field "{}" of type "{}""#,
-        arg_name, field_name, type_name
-    )
+    format!(r#"Unknown argument "{arg_name}" on field "{field_name}" of type "{type_name}""#)
 }
 
 fn directive_error_message(arg_name: &str, directive_name: &str) -> String {
-    format!(
-        r#"Unknown argument "{}" on directive "{}""#,
-        arg_name, directive_name
-    )
+    format!(r#"Unknown argument "{arg_name}" on directive "{directive_name}""#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/known_directives.rs b/juniper/src/validation/rules/known_directives.rs
index 291e17db..9a2b9f5b 100644
--- a/juniper/src/validation/rules/known_directives.rs
+++ b/juniper/src/validation/rules/known_directives.rs
@@ -154,14 +154,11 @@ where
 }
 
 fn unknown_error_message(directive_name: &str) -> String {
-    format!(r#"Unknown directive "{}""#, directive_name)
+    format!(r#"Unknown directive "{directive_name}""#)
 }
 
 fn misplaced_error_message(directive_name: &str, location: &DirectiveLocation) -> String {
-    format!(
-        r#"Directive "{}" may not be used on {}"#,
-        directive_name, location
-    )
+    format!(r#"Directive "{directive_name}" may not be used on {location}"#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/known_fragment_names.rs b/juniper/src/validation/rules/known_fragment_names.rs
index 8795de4a..ac4b7b19 100644
--- a/juniper/src/validation/rules/known_fragment_names.rs
+++ b/juniper/src/validation/rules/known_fragment_names.rs
@@ -28,7 +28,7 @@ where
 }
 
 fn error_message(frag_name: &str) -> String {
-    format!(r#"Unknown fragment: "{}""#, frag_name)
+    format!(r#"Unknown fragment: "{frag_name}""#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/known_type_names.rs b/juniper/src/validation/rules/known_type_names.rs
index b5b2c936..4f2dffc2 100644
--- a/juniper/src/validation/rules/known_type_names.rs
+++ b/juniper/src/validation/rules/known_type_names.rs
@@ -56,7 +56,7 @@ fn validate_type<'a, S: Debug>(
 }
 
 fn error_message(type_name: &str) -> String {
-    format!(r#"Unknown type "{}""#, type_name)
+    format!(r#"Unknown type "{type_name}""#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/no_fragment_cycles.rs b/juniper/src/validation/rules/no_fragment_cycles.rs
index c5489e08..3a6782a7 100644
--- a/juniper/src/validation/rules/no_fragment_cycles.rs
+++ b/juniper/src/validation/rules/no_fragment_cycles.rs
@@ -126,7 +126,7 @@ impl<'a> CycleDetector<'a> {
 }
 
 fn error_message(frag_name: &str) -> String {
-    format!(r#"Cannot spread fragment "{}""#, frag_name)
+    format!(r#"Cannot spread fragment "{frag_name}""#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/no_undefined_variables.rs b/juniper/src/validation/rules/no_undefined_variables.rs
index 8f13f191..18287c49 100644
--- a/juniper/src/validation/rules/no_undefined_variables.rs
+++ b/juniper/src/validation/rules/no_undefined_variables.rs
@@ -151,12 +151,9 @@ where
 
 fn error_message(var_name: &str, op_name: Option<&str>) -> String {
     if let Some(op_name) = op_name {
-        format!(
-            r#"Variable "${}" is not defined by operation "{}""#,
-            var_name, op_name
-        )
+        format!(r#"Variable "${var_name}" is not defined by operation "{op_name}""#)
     } else {
-        format!(r#"Variable "${}" is not defined"#, var_name)
+        format!(r#"Variable "${var_name}" is not defined"#)
     }
 }
 
diff --git a/juniper/src/validation/rules/no_unused_fragments.rs b/juniper/src/validation/rules/no_unused_fragments.rs
index 97b2bcf8..38a360b5 100644
--- a/juniper/src/validation/rules/no_unused_fragments.rs
+++ b/juniper/src/validation/rules/no_unused_fragments.rs
@@ -104,7 +104,7 @@ where
 }
 
 fn error_message(frag_name: &str) -> String {
-    format!(r#"Fragment "{}" is never used"#, frag_name)
+    format!(r#"Fragment "{frag_name}" is never used"#)
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/no_unused_variables.rs b/juniper/src/validation/rules/no_unused_variables.rs
index 35e5f933..811acde5 100644
--- a/juniper/src/validation/rules/no_unused_variables.rs
+++ b/juniper/src/validation/rules/no_unused_variables.rs
@@ -142,12 +142,9 @@ where
 
 fn error_message(var_name: &str, op_name: Option<&str>) -> String {
     if let Some(op_name) = op_name {
-        format!(
-            r#"Variable "${}" is not used by operation "{}""#,
-            var_name, op_name
-        )
+        format!(r#"Variable "${var_name}" is not used by operation "{op_name}""#)
     } else {
-        format!(r#"Variable "${}" is not used"#, var_name)
+        format!(r#"Variable "${var_name}" is not used"#)
     }
 }
 
diff --git a/juniper/src/validation/rules/overlapping_fields_can_be_merged.rs b/juniper/src/validation/rules/overlapping_fields_can_be_merged.rs
index 1b13f393..5a9260b1 100644
--- a/juniper/src/validation/rules/overlapping_fields_can_be_merged.rs
+++ b/juniper/src/validation/rules/overlapping_fields_can_be_merged.rs
@@ -376,10 +376,9 @@ impl<'a, S: Debug> OverlappingFieldsCanBeMerged<'a, S> {
             if name1 != name2 {
                 return Some(Conflict(
                     ConflictReason(
-                        response_name.to_owned(),
+                        response_name.into(),
                         ConflictReasonMessage::Message(format!(
-                            "{} and {} are different fields",
-                            name1, name2
+                            "{name1} and {name2} are different fields",
                         )),
                     ),
                     vec![ast1.start],
@@ -390,8 +389,8 @@ impl<'a, S: Debug> OverlappingFieldsCanBeMerged<'a, S> {
             if !self.is_same_arguments(&ast1.item.arguments, &ast2.item.arguments) {
                 return Some(Conflict(
                     ConflictReason(
-                        response_name.to_owned(),
-                        ConflictReasonMessage::Message("they have differing arguments".to_owned()),
+                        response_name.into(),
+                        ConflictReasonMessage::Message("they have differing arguments".into()),
                     ),
                     vec![ast1.start],
                     vec![ast2.start],
@@ -406,10 +405,9 @@ impl<'a, S: Debug> OverlappingFieldsCanBeMerged<'a, S> {
             if self.is_type_conflict(ctx, t1, t2) {
                 return Some(Conflict(
                     ConflictReason(
-                        response_name.to_owned(),
+                        response_name.into(),
                         ConflictReasonMessage::Message(format!(
-                            "they return conflicting types {} and {}",
-                            t1, t2
+                            "they return conflicting types {t1} and {t2}",
                         )),
                     ),
                     vec![ast1.start],
@@ -513,7 +511,7 @@ impl<'a, S: Debug> OverlappingFieldsCanBeMerged<'a, S> {
 
         Some(Conflict(
             ConflictReason(
-                response_name.to_owned(),
+                response_name.into(),
                 ConflictReasonMessage::Nested(conflicts.iter().map(|c| c.0.clone()).collect()),
             ),
             vec![*pos1]
@@ -722,10 +720,8 @@ where
 fn error_message(reason_name: &str, reason: &ConflictReasonMessage) -> String {
     let suffix = "Use different aliases on the fields to fetch both if this was intentional";
     format!(
-        r#"Fields "{}" conflict because {}. {}"#,
-        reason_name,
+        r#"Fields "{reason_name}" conflict because {}. {suffix}"#,
         format_reason(reason),
-        suffix
     )
 }
 
@@ -736,9 +732,8 @@ fn format_reason(reason: &ConflictReasonMessage) -> String {
             .iter()
             .map(|&ConflictReason(ref name, ref subreason)| {
                 format!(
-                    r#"subfields "{}" conflict because {}"#,
-                    name,
-                    format_reason(subreason)
+                    r#"subfields "{name}" conflict because {}"#,
+                    format_reason(subreason),
                 )
             })
             .collect::<Vec<_>>()
@@ -872,7 +867,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "fido",
-                    &Message("name and nickname are different fields".to_owned()),
+                    &Message("name and nickname are different fields".into()),
                 ),
                 &[
                     SourcePosition::new(78, 2, 12),
@@ -912,7 +907,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "name",
-                    &Message("nickname and name are different fields".to_owned()),
+                    &Message("nickname and name are different fields".into()),
                 ),
                 &[
                     SourcePosition::new(71, 2, 12),
@@ -935,7 +930,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "doesKnowCommand",
-                    &Message("they have differing arguments".to_owned()),
+                    &Message("they have differing arguments".into()),
                 ),
                 &[
                     SourcePosition::new(57, 2, 12),
@@ -958,7 +953,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "doesKnowCommand",
-                    &Message("they have differing arguments".to_owned()),
+                    &Message("they have differing arguments".into()),
                 ),
                 &[
                     SourcePosition::new(57, 2, 12),
@@ -981,7 +976,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "doesKnowCommand",
-                    &Message("they have differing arguments".to_owned()),
+                    &Message("they have differing arguments".into()),
                 ),
                 &[
                     SourcePosition::new(57, 2, 12),
@@ -1025,10 +1020,7 @@ mod tests {
           }
         "#,
             &[RuleError::new(
-                &error_message(
-                    "x",
-                    &Message("name and barks are different fields".to_owned()),
-                ),
+                &error_message("x", &Message("name and barks are different fields".into())),
                 &[
                     SourcePosition::new(101, 6, 12),
                     SourcePosition::new(163, 9, 12),
@@ -1066,10 +1058,7 @@ mod tests {
         "#,
             &[
                 RuleError::new(
-                    &error_message(
-                        "x",
-                        &Message("name and barks are different fields".to_owned()),
-                    ),
+                    &error_message("x", &Message("name and barks are different fields".into())),
                     &[
                         SourcePosition::new(235, 13, 14),
                         SourcePosition::new(311, 17, 12),
@@ -1078,7 +1067,7 @@ mod tests {
                 RuleError::new(
                     &error_message(
                         "x",
-                        &Message("name and nickname are different fields".to_owned()),
+                        &Message("name and nickname are different fields".into()),
                     ),
                     &[
                         SourcePosition::new(235, 13, 14),
@@ -1088,7 +1077,7 @@ mod tests {
                 RuleError::new(
                     &error_message(
                         "x",
-                        &Message("barks and nickname are different fields".to_owned()),
+                        &Message("barks and nickname are different fields".into()),
                     ),
                     &[
                         SourcePosition::new(311, 17, 12),
@@ -1117,8 +1106,8 @@ mod tests {
                 &error_message(
                     "dog",
                     &Nested(vec![ConflictReason(
-                        "x".to_owned(),
-                        Message("name and barks are different fields".to_owned()),
+                        "x".into(),
+                        Message("name and barks are different fields".into()),
                     )]),
                 ),
                 &[
@@ -1152,12 +1141,12 @@ mod tests {
                     "dog",
                     &Nested(vec![
                         ConflictReason(
-                            "x".to_owned(),
-                            Message("barks and nickname are different fields".to_owned()),
+                            "x".into(),
+                            Message("barks and nickname are different fields".into()),
                         ),
                         ConflictReason(
-                            "y".to_owned(),
-                            Message("name and barkVolume are different fields".to_owned()),
+                            "y".into(),
+                            Message("name and barkVolume are different fields".into()),
                         ),
                     ]),
                 ),
@@ -1195,10 +1184,10 @@ mod tests {
                 &error_message(
                     "human",
                     &Nested(vec![ConflictReason(
-                        "relatives".to_owned(),
+                        "relatives".into(),
                         Nested(vec![ConflictReason(
-                            "x".to_owned(),
-                            Message("name and iq are different fields".to_owned()),
+                            "x".into(),
+                            Message("name and iq are different fields".into()),
                         )]),
                     )]),
                 ),
@@ -1239,8 +1228,8 @@ mod tests {
                 &error_message(
                     "relatives",
                     &Nested(vec![ConflictReason(
-                        "x".to_owned(),
-                        Message("iq and name are different fields".to_owned()),
+                        "x".into(),
+                        Message("iq and name are different fields".into()),
                     )]),
                 ),
                 &[
@@ -1286,8 +1275,8 @@ mod tests {
                 &error_message(
                     "relatives",
                     &Nested(vec![ConflictReason(
-                        "x".to_owned(),
-                        Message("iq and name are different fields".to_owned()),
+                        "x".into(),
+                        Message("iq and name are different fields".into()),
                     )]),
                 ),
                 &[
@@ -1333,12 +1322,12 @@ mod tests {
                     "dog",
                     &Nested(vec![
                         ConflictReason(
-                            "x".to_owned(),
-                            Message("name and barks are different fields".to_owned()),
+                            "x".into(),
+                            Message("name and barks are different fields".into()),
                         ),
                         ConflictReason(
-                            "y".to_owned(),
-                            Message("barkVolume and nickname are different fields".to_owned()),
+                            "y".into(),
+                            Message("barkVolume and nickname are different fields".into()),
                         ),
                     ]),
                 ),
@@ -1794,7 +1783,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "scalar",
-                    &Message("they return conflicting types Int and String!".to_owned()),
+                    &Message("they return conflicting types Int and String!".into()),
                 ),
                 &[
                     SourcePosition::new(88, 4, 18),
@@ -1858,7 +1847,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "scalar",
-                    &Message("they return conflicting types Int and String".to_owned()),
+                    &Message("they return conflicting types Int and String".into()),
                 ),
                 &[
                     SourcePosition::new(89, 4, 18),
@@ -1922,8 +1911,8 @@ mod tests {
                 &error_message(
                     "other",
                     &Nested(vec![ConflictReason(
-                        "otherField".to_owned(),
-                        Message("otherField and unrelatedField are different fields".to_owned()),
+                        "otherField".into(),
+                        Message("otherField and unrelatedField are different fields".into()),
                     )]),
                 ),
                 &[
@@ -1957,7 +1946,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "scalar",
-                    &Message("they return conflicting types String! and String".to_owned()),
+                    &Message("they return conflicting types String! and String".into()),
                 ),
                 &[
                     SourcePosition::new(100, 4, 18),
@@ -1992,7 +1981,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "box",
-                    &Message("they return conflicting types [StringBox] and StringBox".to_owned()),
+                    &Message("they return conflicting types [StringBox] and StringBox".into()),
                 ),
                 &[
                     SourcePosition::new(89, 4, 18),
@@ -2024,7 +2013,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "box",
-                    &Message("they return conflicting types StringBox and [StringBox]".to_owned()),
+                    &Message("they return conflicting types StringBox and [StringBox]".into()),
                 ),
                 &[
                     SourcePosition::new(89, 4, 18),
@@ -2060,7 +2049,7 @@ mod tests {
             &[RuleError::new(
                 &error_message(
                     "val",
-                    &Message("scalar and unrelatedField are different fields".to_owned()),
+                    &Message("scalar and unrelatedField are different fields".into()),
                 ),
                 &[
                     SourcePosition::new(126, 5, 20),
@@ -2096,8 +2085,8 @@ mod tests {
                 &error_message(
                     "box",
                     &Nested(vec![ConflictReason(
-                        "scalar".to_owned(),
-                        Message("they return conflicting types String and Int".to_owned()),
+                        "scalar".into(),
+                        Message("they return conflicting types String and Int".into()),
                     )]),
                 ),
                 &[
@@ -2227,10 +2216,10 @@ mod tests {
                 &error_message(
                     "edges",
                     &Nested(vec![ConflictReason(
-                        "node".to_owned(),
+                        "node".into(),
                         Nested(vec![ConflictReason(
-                            "id".to_owned(),
-                            Message("name and id are different fields".to_owned()),
+                            "id".into(),
+                            Message("name and id are different fields".into()),
                         )]),
                     )]),
                 ),
@@ -2278,7 +2267,7 @@ mod tests {
     #[test]
     fn error_message_contains_hint_for_alias_conflict() {
         assert_eq!(
-            &error_message("x", &Message("a and b are different fields".to_owned())),
+            &error_message("x", &Message("a and b are different fields".into())),
             "Fields \"x\" conflict because a and b are different fields. Use \
              different aliases on the fields to fetch both if this \
              was intentional"
diff --git a/juniper/src/validation/rules/possible_fragment_spreads.rs b/juniper/src/validation/rules/possible_fragment_spreads.rs
index 53ef05a3..c9e11f6f 100644
--- a/juniper/src/validation/rules/possible_fragment_spreads.rs
+++ b/juniper/src/validation/rules/possible_fragment_spreads.rs
@@ -119,15 +119,13 @@ where
 fn error_message(frag_name: Option<&str>, parent_type_name: &str, frag_type: &str) -> String {
     if let Some(frag_name) = frag_name {
         format!(
-            "Fragment \"{}\" cannot be spread here as objects of type \
-             \"{}\" can never be of type \"{}\"",
-            frag_name, parent_type_name, frag_type
+            "Fragment \"{frag_name}\" cannot be spread here as objects of type \
+             \"{parent_type_name}\" can never be of type \"{frag_type}\"",
         )
     } else {
         format!(
-            "Fragment cannot be spread here as objects of type \"{}\" \
-             can never be of type \"{}\"",
-            parent_type_name, frag_type
+            "Fragment cannot be spread here as objects of type \
+             \"{parent_type_name}\" can never be of type \"{frag_type}\"",
         )
     }
 }
diff --git a/juniper/src/validation/rules/provided_non_null_arguments.rs b/juniper/src/validation/rules/provided_non_null_arguments.rs
index eb76c150..35672e18 100644
--- a/juniper/src/validation/rules/provided_non_null_arguments.rs
+++ b/juniper/src/validation/rules/provided_non_null_arguments.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{
     ast::{Directive, Field},
     parser::Spanning,
@@ -35,11 +37,7 @@ where
                         .is_none()
                 {
                     ctx.report_error(
-                        &field_error_message(
-                            field_name,
-                            &meta_arg.name,
-                            &format!("{}", meta_arg.arg_type),
-                        ),
+                        &field_error_message(field_name, &meta_arg.name, &meta_arg.arg_type),
                         &[field.start],
                     );
                 }
@@ -72,7 +70,7 @@ where
                         &directive_error_message(
                             directive_name,
                             &meta_arg.name,
-                            &format!("{}", meta_arg.arg_type),
+                            &meta_arg.arg_type,
                         ),
                         &[directive.start],
                     );
@@ -82,17 +80,23 @@ where
     }
 }
 
-fn field_error_message(field_name: &str, arg_name: &str, type_name: &str) -> String {
+fn field_error_message(
+    field_name: impl fmt::Display,
+    arg_name: impl fmt::Display,
+    type_name: impl fmt::Display,
+) -> String {
     format!(
-        r#"Field "{}" argument "{}" of type "{}" is required but not provided"#,
-        field_name, arg_name, type_name
+        r#"Field "{field_name}" argument "{arg_name}" of type "{type_name}" is required but not provided"#,
     )
 }
 
-fn directive_error_message(directive_name: &str, arg_name: &str, type_name: &str) -> String {
+fn directive_error_message(
+    directive_name: impl fmt::Display,
+    arg_name: impl fmt::Display,
+    type_name: impl fmt::Display,
+) -> String {
     format!(
-        r#"Directive "@{}" argument "{}" of type "{}" is required but not provided"#,
-        directive_name, arg_name, type_name
+        r#"Directive "@{directive_name}" argument "{arg_name}" of type "{type_name}" is required but not provided"#,
     )
 }
 
diff --git a/juniper/src/validation/rules/scalar_leafs.rs b/juniper/src/validation/rules/scalar_leafs.rs
index fe5ac777..00a92dad 100644
--- a/juniper/src/validation/rules/scalar_leafs.rs
+++ b/juniper/src/validation/rules/scalar_leafs.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{
     ast::Field,
     parser::Spanning,
@@ -23,11 +25,11 @@ where
         {
             match (field_type.is_leaf(), &field.item.selection_set) {
                 (true, &Some(_)) => Some(RuleError::new(
-                    &no_allowed_error_message(field_name, &format!("{}", field_type_literal)),
+                    &no_allowed_error_message(field_name, field_type_literal),
                     &[field.start],
                 )),
                 (false, &None) => Some(RuleError::new(
-                    &required_error_message(field_name, &format!("{}", field_type_literal)),
+                    &required_error_message(field_name, field_type_literal),
                     &[field.start],
                 )),
                 _ => None,
@@ -42,17 +44,15 @@ where
     }
 }
 
-fn no_allowed_error_message(field_name: &str, type_name: &str) -> String {
+fn no_allowed_error_message(field_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
     format!(
-        r#"Field "{}" must not have a selection since type {} has no subfields"#,
-        field_name, type_name
+        r#"Field "{field_name}" must not have a selection since type {type_name} has no subfields"#,
     )
 }
 
-fn required_error_message(field_name: &str, type_name: &str) -> String {
+fn required_error_message(field_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
     format!(
-        r#"Field "{}" of type "{}" must have a selection of subfields. Did you mean "{} {{ ... }}"?"#,
-        field_name, type_name, field_name
+        r#"Field "{field_name}" of type "{type_name}" must have a selection of subfields. Did you mean "{field_name} {{ ... }}"?"#,
     )
 }
 
diff --git a/juniper/src/validation/rules/unique_argument_names.rs b/juniper/src/validation/rules/unique_argument_names.rs
index 0b6ae6d6..697e0a27 100644
--- a/juniper/src/validation/rules/unique_argument_names.rs
+++ b/juniper/src/validation/rules/unique_argument_names.rs
@@ -46,7 +46,7 @@ where
 }
 
 fn error_message(arg_name: &str) -> String {
-    format!("There can only be one argument named \"{}\"", arg_name)
+    format!("There can only be one argument named \"{arg_name}\"")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/unique_fragment_names.rs b/juniper/src/validation/rules/unique_fragment_names.rs
index 2bcbb440..f54e46d1 100644
--- a/juniper/src/validation/rules/unique_fragment_names.rs
+++ b/juniper/src/validation/rules/unique_fragment_names.rs
@@ -41,7 +41,7 @@ where
 }
 
 fn duplicate_message(frag_name: &str) -> String {
-    format!("There can only be one fragment named {}", frag_name)
+    format!("There can only be one fragment named {frag_name}")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/unique_input_field_names.rs b/juniper/src/validation/rules/unique_input_field_names.rs
index db507502..7108c767 100644
--- a/juniper/src/validation/rules/unique_input_field_names.rs
+++ b/juniper/src/validation/rules/unique_input_field_names.rs
@@ -53,7 +53,7 @@ where
 type SpannedObject<'a, S> = Spanning<&'a Vec<(Spanning<String>, Spanning<InputValue<S>>)>>;
 
 fn error_message(field_name: &str) -> String {
-    format!("There can only be one input field named \"{}\"", field_name)
+    format!("There can only be one input field named \"{field_name}\"")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/unique_operation_names.rs b/juniper/src/validation/rules/unique_operation_names.rs
index 4d7e56f1..8f693696 100644
--- a/juniper/src/validation/rules/unique_operation_names.rs
+++ b/juniper/src/validation/rules/unique_operation_names.rs
@@ -40,7 +40,7 @@ where
 }
 
 fn error_message(op_name: &str) -> String {
-    format!("There can only be one operation named {}", op_name)
+    format!("There can only be one operation named {op_name}")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/unique_variable_names.rs b/juniper/src/validation/rules/unique_variable_names.rs
index 0c32706b..738e634b 100644
--- a/juniper/src/validation/rules/unique_variable_names.rs
+++ b/juniper/src/validation/rules/unique_variable_names.rs
@@ -46,7 +46,7 @@ where
 }
 
 fn error_message(var_name: &str) -> String {
-    format!("There can only be one variable named {}", var_name)
+    format!("There can only be one variable named {var_name}")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/variables_are_input_types.rs b/juniper/src/validation/rules/variables_are_input_types.rs
index 0336b618..168119d6 100644
--- a/juniper/src/validation/rules/variables_are_input_types.rs
+++ b/juniper/src/validation/rules/variables_are_input_types.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{
     ast::VariableDefinition,
     parser::Spanning,
@@ -26,7 +28,7 @@ where
         {
             if !var_type.is_input() {
                 ctx.report_error(
-                    &error_message(var_name.item, &format!("{}", var_def.var_type.item)),
+                    &error_message(var_name.item, &var_def.var_type.item),
                     &[var_def.var_type.start],
                 );
             }
@@ -34,11 +36,8 @@ where
     }
 }
 
-fn error_message(var_name: &str, type_name: &str) -> String {
-    format!(
-        "Variable \"{}\" cannot be of non-input type \"{}\"",
-        var_name, type_name
-    )
+fn error_message(var_name: impl fmt::Display, type_name: impl fmt::Display) -> String {
+    format!("Variable \"{var_name}\" cannot be of non-input type \"{type_name}\"")
 }
 
 #[cfg(test)]
diff --git a/juniper/src/validation/rules/variables_in_allowed_position.rs b/juniper/src/validation/rules/variables_in_allowed_position.rs
index 1f3dff59..550b47a8 100644
--- a/juniper/src/validation/rules/variables_in_allowed_position.rs
+++ b/juniper/src/validation/rules/variables_in_allowed_position.rs
@@ -1,7 +1,7 @@
 use std::{
     borrow::Cow,
     collections::{HashMap, HashSet},
-    fmt::Debug,
+    fmt,
 };
 
 use crate::{
@@ -17,7 +17,7 @@ pub enum Scope<'a> {
     Fragment(&'a str),
 }
 
-pub struct VariableInAllowedPosition<'a, S: Debug + 'a> {
+pub struct VariableInAllowedPosition<'a, S: fmt::Debug + 'a> {
     spreads: HashMap<Scope<'a>, HashSet<&'a str>>,
     variable_usages: HashMap<Scope<'a>, Vec<(Spanning<&'a String>, Type<'a>)>>,
     #[allow(clippy::type_complexity)]
@@ -25,7 +25,7 @@ pub struct VariableInAllowedPosition<'a, S: Debug + 'a> {
     current_scope: Option<Scope<'a>>,
 }
 
-pub fn factory<'a, S: Debug>() -> VariableInAllowedPosition<'a, S> {
+pub fn factory<'a, S: fmt::Debug>() -> VariableInAllowedPosition<'a, S> {
     VariableInAllowedPosition {
         spreads: HashMap::new(),
         variable_usages: HashMap::new(),
@@ -34,7 +34,7 @@ pub fn factory<'a, S: Debug>() -> VariableInAllowedPosition<'a, S> {
     }
 }
 
-impl<'a, S: Debug> VariableInAllowedPosition<'a, S> {
+impl<'a, S: fmt::Debug> VariableInAllowedPosition<'a, S> {
     fn collect_incorrect_usages(
         &self,
         from: &Scope<'a>,
@@ -66,11 +66,7 @@ impl<'a, S: Debug> VariableInAllowedPosition<'a, S> {
 
                     if !ctx.schema.is_subtype(&expected_type, var_type) {
                         ctx.report_error(
-                            &error_message(
-                                var_name.item,
-                                &format!("{}", expected_type),
-                                &format!("{}", var_type),
-                            ),
+                            &error_message(var_name.item, expected_type, var_type),
                             &[var_def_name.start, var_name.start],
                         );
                     }
@@ -157,10 +153,13 @@ where
     }
 }
 
-fn error_message(var_name: &str, type_name: &str, expected_type_name: &str) -> String {
+fn error_message(
+    var_name: impl fmt::Display,
+    type_name: impl fmt::Display,
+    expected_type_name: impl fmt::Display,
+) -> String {
     format!(
-        "Variable \"{}\" of type \"{}\" used in position expecting type \"{}\"",
-        var_name, type_name, expected_type_name
+        "Variable \"{var_name}\" of type \"{type_name}\" used in position expecting type \"{expected_type_name}\"",
     )
 }
 
diff --git a/juniper/src/validation/test_harness.rs b/juniper/src/validation/test_harness.rs
index 1772b639..492e4564 100644
--- a/juniper/src/validation/test_harness.rs
+++ b/juniper/src/validation/test_harness.rs
@@ -920,7 +920,7 @@ where
     ));
 
     let doc =
-        parse_document_source(q, &root.schema).expect(&format!("Parse error on input {:#?}", q));
+        parse_document_source(q, &root.schema).expect(&format!("Parse error on input {q:#?}"));
     let mut ctx = ValidatorContext::new(unsafe { mem::transmute(&root.schema) }, &doc);
 
     visit_fn(&mut ctx, unsafe { mem::transmute(doc.as_slice()) });
diff --git a/juniper/src/value/mod.rs b/juniper/src/value/mod.rs
index e3457c8e..6a160807 100644
--- a/juniper/src/value/mod.rs
+++ b/juniper/src/value/mod.rs
@@ -196,15 +196,15 @@ impl<S: ScalarValue> fmt::Display for Value<S> {
             Self::Null => write!(f, "null"),
             Self::Scalar(s) => {
                 if let Some(string) = s.as_string() {
-                    write!(f, "\"{}\"", string)
+                    write!(f, "\"{string}\"")
                 } else {
-                    write!(f, "{}", s)
+                    write!(f, "{s}")
                 }
             }
             Self::List(list) => {
                 write!(f, "[")?;
                 for (idx, item) in list.iter().enumerate() {
-                    write!(f, "{}", item)?;
+                    write!(f, "{item}")?;
                     if idx < list.len() - 1 {
                         write!(f, ", ")?;
                     }
@@ -216,7 +216,7 @@ impl<S: ScalarValue> fmt::Display for Value<S> {
             Self::Object(obj) => {
                 write!(f, "{{")?;
                 for (idx, (key, value)) in obj.iter().enumerate() {
-                    write!(f, "\"{}\": {}", key, value)?;
+                    write!(f, "\"{key}\": {value}")?;
 
                     if idx < obj.field_count() - 1 {
                         write!(f, ", ")?;
@@ -287,52 +287,52 @@ mod tests {
     #[test]
     fn display_null() {
         let s: Value = graphql_value!(null);
-        assert_eq!("null", format!("{}", s));
+        assert_eq!(s.to_string(), "null");
     }
 
     #[test]
     fn display_int() {
         let s: Value = graphql_value!(123);
-        assert_eq!("123", format!("{}", s));
+        assert_eq!(s.to_string(), "123");
     }
 
     #[test]
     fn display_float() {
         let s: Value = graphql_value!(123.456);
-        assert_eq!("123.456", format!("{}", s));
+        assert_eq!(s.to_string(), "123.456");
     }
 
     #[test]
     fn display_string() {
         let s: Value = graphql_value!("foo");
-        assert_eq!("\"foo\"", format!("{}", s));
+        assert_eq!(s.to_string(), "\"foo\"");
     }
 
     #[test]
     fn display_bool() {
         let s: Value = graphql_value!(false);
-        assert_eq!("false", format!("{}", s));
+        assert_eq!(s.to_string(), "false");
 
         let s: Value = graphql_value!(true);
-        assert_eq!("true", format!("{}", s));
+        assert_eq!(s.to_string(), "true");
     }
 
     #[test]
     fn display_list() {
         let s: Value = graphql_value!([1, null, "foo"]);
-        assert_eq!("[1, null, \"foo\"]", format!("{}", s));
+        assert_eq!(s.to_string(), "[1, null, \"foo\"]");
     }
 
     #[test]
     fn display_list_one_element() {
         let s: Value = graphql_value!([1]);
-        assert_eq!("[1]", format!("{}", s));
+        assert_eq!(s.to_string(), "[1]");
     }
 
     #[test]
     fn display_list_empty() {
         let s: Value = graphql_value!([]);
-        assert_eq!("[]", format!("{}", s));
+        assert_eq!(s.to_string(), "[]");
     }
 
     #[test]
@@ -343,8 +343,8 @@ mod tests {
             "string": "foo",
         });
         assert_eq!(
+            s.to_string(),
             r#"{"int": 1, "null": null, "string": "foo"}"#,
-            format!("{}", s)
         );
     }
 
@@ -353,12 +353,12 @@ mod tests {
         let s: Value = graphql_value!({
             "int": 1,
         });
-        assert_eq!(r#"{"int": 1}"#, format!("{}", s));
+        assert_eq!(s.to_string(), r#"{"int": 1}"#);
     }
 
     #[test]
     fn display_object_empty() {
         let s: Value = graphql_value!({});
-        assert_eq!(r#"{}"#, format!("{}", s));
+        assert_eq!(s.to_string(), r#"{}"#);
     }
 }
diff --git a/juniper/src/value/object.rs b/juniper/src/value/object.rs
index 909abe3f..4e3deb41 100644
--- a/juniper/src/value/object.rs
+++ b/juniper/src/value/object.rs
@@ -1,4 +1,4 @@
-use std::{iter::FromIterator, mem};
+use std::mem;
 
 use super::Value;
 use indexmap::map::{IndexMap, IntoIter};
diff --git a/juniper/src/value/scalar.rs b/juniper/src/value/scalar.rs
index fa1dd441..f93e7bbf 100644
--- a/juniper/src/value/scalar.rs
+++ b/juniper/src/value/scalar.rs
@@ -34,7 +34,7 @@ pub trait ParseScalarValue<S = DefaultScalarValue> {
 /// integers.
 ///
 /// ```rust
-/// # use std::{fmt, convert::TryInto as _};
+/// # use std::fmt;
 /// #
 /// # use serde::{de, Deserialize, Deserializer, Serialize};
 /// # use juniper::ScalarValue;
diff --git a/juniper_actix/Cargo.toml b/juniper_actix/Cargo.toml
index 72127db6..17c91837 100644
--- a/juniper_actix/Cargo.toml
+++ b/juniper_actix/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_actix"
 version = "0.5.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "`juniper` GraphQL integration with `actix-web`."
 license = "BSD-2-Clause"
 authors = ["Jordao Rosario <jordao.rosario01@gmail.com>"]
diff --git a/juniper_actix/examples/actix_server.rs b/juniper_actix/examples/actix_server.rs
index 5a13b79a..ab27373d 100644
--- a/juniper_actix/examples/actix_server.rs
+++ b/juniper_actix/examples/actix_server.rs
@@ -21,7 +21,7 @@ pub struct User {
     name: String,
 }
 
-#[derive(Default, Clone)]
+#[derive(Clone, Default)]
 pub struct Database {
     ///this could be a database connection
     users: HashMap<i32, User>,
@@ -33,28 +33,28 @@ impl Database {
             1,
             User {
                 id: 1,
-                name: "Aron".to_string(),
+                name: "Aron".into(),
             },
         );
         users.insert(
             2,
             User {
                 id: 2,
-                name: "Bea".to_string(),
+                name: "Bea".into(),
             },
         );
         users.insert(
             3,
             User {
                 id: 3,
-                name: "Carl".to_string(),
+                name: "Carl".into(),
             },
         );
         users.insert(
             4,
             User {
                 id: 4,
-                name: "Dora".to_string(),
+                name: "Dora".into(),
             },
         );
         Database { users }
diff --git a/juniper_actix/src/lib.rs b/juniper_actix/src/lib.rs
index c88c1b00..3c6192e6 100644
--- a/juniper_actix/src/lib.rs
+++ b/juniper_actix/src/lib.rs
@@ -368,7 +368,7 @@ pub mod subscriptions {
                 Err(e) => {
                     let reason = ws::CloseReason {
                         code: ws::CloseCode::Error,
-                        description: Some(format!("error serializing response: {}", e)),
+                        description: Some(format!("error serializing response: {e}")),
                     };
 
                     // TODO: trace
@@ -389,7 +389,7 @@ pub mod subscriptions {
     #[derive(Debug)]
     struct Message(ws::Message);
 
-    impl<S: ScalarValue> std::convert::TryFrom<Message> for ClientMessage<S> {
+    impl<S: ScalarValue> TryFrom<Message> for ClientMessage<S> {
         type Error = Error;
 
         fn try_from(msg: Message) -> Result<Self, Self::Error> {
@@ -416,7 +416,7 @@ pub mod subscriptions {
     impl fmt::Display for Error {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             match self {
-                Self::Serde(e) => write!(f, "serde error: {}", e),
+                Self::Serde(e) => write!(f, "serde error: {e}"),
                 Self::UnexpectedClientMessage => {
                     write!(f, "unexpected message received from client")
                 }
@@ -712,7 +712,7 @@ mod tests {
             self.make_request(
                 TestRequest::post()
                     .append_header(("content-type", "application/json"))
-                    .set_payload(body.to_string())
+                    .set_payload(body.to_owned())
                     .uri(url),
             )
         }
@@ -721,7 +721,7 @@ mod tests {
             self.make_request(
                 TestRequest::post()
                     .append_header(("content-type", "application/graphql"))
-                    .set_payload(body.to_string())
+                    .set_payload(body.to_owned())
                     .uri(url),
             )
         }
@@ -735,7 +735,7 @@ mod tests {
             .unwrap()
             .to_str()
             .unwrap()
-            .to_string();
+            .into();
         let body = take_response_body_string(resp).await;
         TestResponse {
             status_code: status_code as i32,
@@ -797,29 +797,28 @@ mod subscription_tests {
                         framed
                             .send(ws::Message::Text(body.to_owned().into()))
                             .await
-                            .map_err(|e| anyhow::anyhow!("WS error: {:?}", e))?;
+                            .map_err(|e| anyhow::anyhow!("WS error: {e:?}"))?;
                     }
                     WsIntegrationMessage::Expect(body, message_timeout) => {
                         let frame = timeout(Duration::from_millis(*message_timeout), framed.next())
                             .await
                             .map_err(|_| anyhow::anyhow!("Timed-out waiting for message"))?
                             .ok_or_else(|| anyhow::anyhow!("Empty message received"))?
-                            .map_err(|e| anyhow::anyhow!("WS error: {:?}", e))?;
+                            .map_err(|e| anyhow::anyhow!("WS error: {e:?}"))?;
 
                         match frame {
                             ws::Frame::Text(ref bytes) => {
                                 let expected_value =
                                     serde_json::from_str::<serde_json::Value>(body)
-                                        .map_err(|e| anyhow::anyhow!("Serde error: {:?}", e))?;
+                                        .map_err(|e| anyhow::anyhow!("Serde error: {e:?}"))?;
 
                                 let value: serde_json::Value = serde_json::from_slice(bytes)
-                                    .map_err(|e| anyhow::anyhow!("Serde error: {:?}", e))?;
+                                    .map_err(|e| anyhow::anyhow!("Serde error: {e:?}"))?;
 
                                 if value != expected_value {
                                     return Err(anyhow::anyhow!(
-                                        "Expected message: {}. Received message: {}",
-                                        expected_value,
-                                        value,
+                                        "Expected message: {expected_value}. \
+                                         Received message: {value}",
                                     ));
                                 }
                             }
diff --git a/juniper_codegen/Cargo.toml b/juniper_codegen/Cargo.toml
index 79ba4d63..ef78a0a2 100644
--- a/juniper_codegen/Cargo.toml
+++ b/juniper_codegen/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_codegen"
 version = "0.16.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "Code generation for `juniper` crate."
 license = "BSD-2-Clause"
 authors = [
diff --git a/juniper_codegen/src/common/default.rs b/juniper_codegen/src/common/default.rs
index 2354345a..a2d00f45 100644
--- a/juniper_codegen/src/common/default.rs
+++ b/juniper_codegen/src/common/default.rs
@@ -15,9 +15,10 @@ use crate::common::parse::ParseBufferExt as _;
 /// Representation of a [GraphQL default value][0] for code generation.
 ///
 /// [0]: https://spec.graphql.org/October2021#DefaultValue
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub(crate) enum Value {
     /// [`Default`] implementation should be used.
+    #[default]
     Default,
 
     /// Explicit [`Expr`]ession to be used as the [default value][0].
@@ -27,12 +28,6 @@ pub(crate) enum Value {
     Expr(Box<syn::Expr>),
 }
 
-impl Default for Value {
-    fn default() -> Self {
-        Self::Default
-    }
-}
-
 impl From<Option<syn::Expr>> for Value {
     fn from(opt: Option<syn::Expr>) -> Self {
         match opt {
diff --git a/juniper_codegen/src/common/description.rs b/juniper_codegen/src/common/description.rs
index 6b9533e6..cd8d739e 100644
--- a/juniper_codegen/src/common/description.rs
+++ b/juniper_codegen/src/common/description.rs
@@ -150,7 +150,7 @@ mod concatenate_test {
     /// Forms a [`Vec`] of [`String`]s out of the provided [`str`]s
     /// [`Iterator`].
     fn to_strings<'i>(source: impl IntoIterator<Item = &'i str>) -> Vec<String> {
-        source.into_iter().map(ToOwned::to_owned).collect()
+        source.into_iter().map(Into::into).collect()
     }
 
     #[test]
diff --git a/juniper_codegen/src/common/diagnostic.rs b/juniper_codegen/src/common/diagnostic.rs
index 1d5ebc9c..d99bb504 100644
--- a/juniper_codegen/src/common/diagnostic.rs
+++ b/juniper_codegen/src/common/diagnostic.rs
@@ -45,22 +45,22 @@ impl fmt::Display for Scope {
             Self::ScalarValueDerive => "built-in scalars",
             Self::UnionAttr | Self::UnionDerive => "union",
         };
-        write!(f, "GraphQL {}", name)
+        write!(f, "GraphQL {name}")
     }
 }
 
 impl Scope {
     fn spec_link(&self) -> String {
-        format!("{}{}", SPEC_URL, self.spec_section())
+        format!("{SPEC_URL}{}", self.spec_section())
     }
 
     pub(crate) fn custom<S: AsRef<str>>(&self, span: Span, msg: S) -> Diagnostic {
-        Diagnostic::spanned(span, Level::Error, format!("{} {}", self, msg.as_ref()))
+        Diagnostic::spanned(span, Level::Error, format!("{self} {}", msg.as_ref()))
             .note(self.spec_link())
     }
 
     pub(crate) fn error(&self, err: syn::Error) -> Diagnostic {
-        Diagnostic::spanned(err.span(), Level::Error, format!("{} {}", self, err))
+        Diagnostic::spanned(err.span(), Level::Error, format!("{self} {err}"))
             .note(self.spec_link())
     }
 
@@ -69,7 +69,7 @@ impl Scope {
     }
 
     pub(crate) fn custom_error<S: AsRef<str>>(&self, span: Span, msg: S) -> syn::Error {
-        syn::Error::new(span, format!("{} {}", self, msg.as_ref()))
+        syn::Error::new(span, format!("{self} {}", msg.as_ref()))
     }
 
     pub(crate) fn no_double_underscore(&self, field: Span) {
@@ -81,7 +81,7 @@ impl Scope {
              system."
                 .into(),
         )
-        .note(format!("{}#sec-Schema", SPEC_URL))
+        .note(format!("{SPEC_URL}#sec-Schema"))
         .emit();
     }
 }
diff --git a/juniper_codegen/src/common/field/arg.rs b/juniper_codegen/src/common/field/arg.rs
index 1874c8ae..6de46111 100644
--- a/juniper_codegen/src/common/field/arg.rs
+++ b/juniper_codegen/src/common/field/arg.rs
@@ -195,10 +195,7 @@ impl Attr {
     fn err_disallowed<S: Spanned>(span: &S, arg: &str) -> syn::Error {
         syn::Error::new(
             span.span(),
-            format!(
-                "attribute argument `#[graphql({} = ...)]` is not allowed here",
-                arg,
-            ),
+            format!("attribute argument `#[graphql({arg} = ...)]` is not allowed here",),
         )
     }
 }
@@ -312,7 +309,7 @@ impl OnMethod {
             quote! { .arg::<#ty>(#name, info) }
         };
 
-        Some(quote! { .argument(registry#method#description) })
+        Some(quote! { .argument(registry #method #description) })
     }
 
     /// Returns generated code for the [`GraphQLValue::resolve_field`] method,
@@ -329,7 +326,7 @@ impl OnMethod {
         match self {
             Self::Regular(arg) => {
                 let (name, ty) = (&arg.name, &arg.ty);
-                let err_text = format!("Missing argument `{}`: {{}}", &name);
+                let err_text = format!("Missing argument `{name}`: {{}}");
 
                 let arg = quote! {
                     args.get::<#ty>(#name).and_then(|opt| opt.map_or_else(|| {
diff --git a/juniper_codegen/src/common/field/mod.rs b/juniper_codegen/src/common/field/mod.rs
index 4ed6d79c..8e8cd297 100644
--- a/juniper_codegen/src/common/field/mod.rs
+++ b/juniper_codegen/src/common/field/mod.rs
@@ -227,7 +227,7 @@ impl Definition {
         ty_name: &str,
     ) -> TokenStream {
         quote! {
-            return Err(::juniper::FieldError::from(format!(
+            return Err(::juniper::FieldError::from(::std::format!(
                 "Field `{}` not found on type `{}`",
                 field,
                 <Self as ::juniper::GraphQLType<#scalar>>::name(info)
@@ -350,7 +350,7 @@ impl Definition {
                     let stream = ::juniper::futures::StreamExt::then(res, move |res| {
                         let executor = executor.clone();
                         let res2: ::juniper::FieldResult<_, #scalar> =
-                            ::juniper::IntoResolvable::into(res, executor.context());
+                            ::juniper::IntoResolvable::into_resolvable(res, executor.context());
                         async move {
                             let ex = executor.as_executor();
                             match res2 {
diff --git a/juniper_codegen/src/common/gen.rs b/juniper_codegen/src/common/gen.rs
index eccd52c7..a0b5e731 100644
--- a/juniper_codegen/src/common/gen.rs
+++ b/juniper_codegen/src/common/gen.rs
@@ -11,7 +11,7 @@ use quote::quote;
 /// [1]: https://spec.graphql.org/October2021#sec-Types
 pub(crate) fn sync_resolving_code() -> TokenStream {
     quote! {
-        ::juniper::IntoResolvable::into(res, executor.context())
+        ::juniper::IntoResolvable::into_resolvable(res, executor.context())
             .and_then(|res| match res {
                 Some((ctx, r)) => executor.replaced_context(ctx).resolve_with_ctx(info, &r),
                 None => Ok(::juniper::Value::null()),
@@ -35,7 +35,7 @@ pub(crate) fn async_resolving_code(ty: Option<&syn::Type>) -> TokenStream {
 
     quote! {
         Box::pin(::juniper::futures::FutureExt::then(fut, move |res #ty| async move {
-            match ::juniper::IntoResolvable::into(res, executor.context())? {
+            match ::juniper::IntoResolvable::into_resolvable(res, executor.context())? {
                 Some((ctx, r)) => {
                     let subexec = executor.replaced_context(ctx);
                     subexec.resolve_with_ctx_async(info, &r).await
diff --git a/juniper_codegen/src/common/parse/attr.rs b/juniper_codegen/src/common/parse/attr.rs
index 03ba8d73..8b3eceec 100644
--- a/juniper_codegen/src/common/parse/attr.rs
+++ b/juniper_codegen/src/common/parse/attr.rs
@@ -49,7 +49,7 @@ pub(crate) mod err {
     pub(crate) fn unknown_arg<S: AsSpan>(span: S, name: &str) -> syn::Error {
         syn::Error::new(
             span.as_span(),
-            format!("unknown `{}` attribute argument", name),
+            format!("unknown `{name}` attribute argument"),
         )
     }
 
diff --git a/juniper_codegen/src/common/parse/mod.rs b/juniper_codegen/src/common/parse/mod.rs
index eaa946d9..53781675 100644
--- a/juniper_codegen/src/common/parse/mod.rs
+++ b/juniper_codegen/src/common/parse/mod.rs
@@ -4,11 +4,7 @@
 pub(crate) mod attr;
 pub(crate) mod downcaster;
 
-use std::{
-    any::TypeId,
-    iter::{self, FromIterator as _},
-    mem,
-};
+use std::{any::TypeId, iter, mem};
 
 use proc_macro2::Span;
 use quote::quote;
diff --git a/juniper_codegen/src/common/rename.rs b/juniper_codegen/src/common/rename.rs
index 2eda94bc..d7c0cac9 100644
--- a/juniper_codegen/src/common/rename.rs
+++ b/juniper_codegen/src/common/rename.rs
@@ -1,7 +1,7 @@
 //! Common functions, definitions and extensions for parsing and code generation
 //! of `#[graphql(rename_all = ...)]` attribute.
 
-use std::{convert::TryFrom, str::FromStr};
+use std::str::FromStr;
 
 use syn::parse::{Parse, ParseStream};
 
@@ -25,7 +25,7 @@ impl Policy {
     /// Applies this [`Policy`] to the given `name`.
     pub(crate) fn apply(&self, name: &str) -> String {
         match self {
-            Self::None => name.to_owned(),
+            Self::None => name.into(),
             Self::CamelCase => to_camel_case(name),
             Self::ScreamingSnakeCase => to_upper_snake_case(name),
         }
diff --git a/juniper_codegen/src/graphql_enum/mod.rs b/juniper_codegen/src/graphql_enum/mod.rs
index 949c7b8d..c14356f6 100644
--- a/juniper_codegen/src/graphql_enum/mod.rs
+++ b/juniper_codegen/src/graphql_enum/mod.rs
@@ -4,8 +4,6 @@
 
 pub(crate) mod derive;
 
-use std::convert::TryInto as _;
-
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
 use syn::{
@@ -407,13 +405,13 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsInputType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::marker::IsInputType<#scalar>
+                for #ident #ty_generics
                 #where_clause {}
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsOutputType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::marker::IsOutputType<#scalar>
+                for #ident #ty_generics
                 #where_clause {}
         }
     }
@@ -448,8 +446,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn name(_ : &Self::TypeInfo) -> Option<&'static str> {
@@ -464,7 +462,7 @@ impl Definition {
                 {
                     let variants = [#( #variants_meta ),*];
 
-                    registry.build_enum_type::<#ident#ty_generics>(info, &variants)
+                    registry.build_enum_type::<#ident #ty_generics>(info, &variants)
                         #description
                         .into_meta()
                 }
@@ -504,8 +502,8 @@ impl Definition {
         });
 
         quote! {
-            impl#impl_generics ::juniper::GraphQLValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 type Context = #context;
@@ -544,8 +542,8 @@ impl Definition {
         let (_, ty_generics, _) = self.generics.split_for_impl();
 
         quote! {
-            impl#impl_generics ::juniper::GraphQLValueAsync<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLValueAsync<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn resolve_async<'__a>(
@@ -584,8 +582,8 @@ impl Definition {
         });
 
         quote! {
-            impl#impl_generics ::juniper::FromInputValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::FromInputValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 type Error = ::std::string::String;
@@ -631,8 +629,8 @@ impl Definition {
         });
 
         quote! {
-            impl#impl_generics ::juniper::ToInputValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::ToInputValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn to_input_value(&self) -> ::juniper::InputValue<#scalar> {
@@ -662,23 +660,23 @@ impl Definition {
         let (_, ty_generics, _) = self.generics.split_for_impl();
 
         quote! {
-            impl#impl_generics ::juniper::macros::reflect::BaseType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const NAME: ::juniper::macros::reflect::Type = #name;
             }
 
-            impl#impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Types =
                     &[<Self as ::juniper::macros::reflect::BaseType<#scalar>>::NAME];
             }
 
-            impl#impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const VALUE: ::juniper::macros::reflect::WrappedValue = 1;
@@ -718,14 +716,14 @@ impl Definition {
                 let mut generics = self.generics.clone();
                 for lt in generics.lifetimes_mut() {
                     let ident = lt.lifetime.ident.unraw();
-                    lt.lifetime.ident = format_ident!("__fa__{}", ident);
+                    lt.lifetime.ident = format_ident!("__fa__{ident}");
                 }
 
                 let lifetimes = generics.lifetimes().map(|lt| &lt.lifetime);
                 let ident = &self.ident;
                 let (_, ty_generics, _) = generics.split_for_impl();
 
-                quote! { for<#( #lifetimes ),*> #ident#ty_generics }
+                quote! { for<#( #lifetimes ),*> #ident #ty_generics }
             } else {
                 quote! { Self }
             };
diff --git a/juniper_codegen/src/graphql_input_object/mod.rs b/juniper_codegen/src/graphql_input_object/mod.rs
index 6e0f18ae..93c21d6f 100644
--- a/juniper_codegen/src/graphql_input_object/mod.rs
+++ b/juniper_codegen/src/graphql_input_object/mod.rs
@@ -4,8 +4,6 @@
 
 pub(crate) mod derive;
 
-use std::convert::TryInto as _;
-
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
 use syn::{
@@ -431,8 +429,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsInputType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::marker::IsInputType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn mark() {
@@ -471,14 +469,14 @@ impl Definition {
                 };
                 let description = &f.description;
 
-                quote! { registry#arg#description }
+                quote! { registry #arg #description }
             })
         });
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn name(_: &Self::TypeInfo) -> Option<&'static str> {
@@ -494,7 +492,7 @@ impl Definition {
                 {
                     let fields = [#( #fields ),*];
                     registry
-                        .build_input_object_type::<#ident#ty_generics>(info, &fields)
+                        .build_input_object_type::<#ident #ty_generics>(info, &fields)
                         #description
                         .into_meta()
                 }
@@ -519,8 +517,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 type Context = #context;
@@ -550,8 +548,8 @@ impl Definition {
         quote! {
             #[allow(non_snake_case)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValueAsync<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::GraphQLValueAsync<#scalar>
+                for #ident #ty_generics
                 #where_clause {}
         }
     }
@@ -610,8 +608,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::FromInputValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::FromInputValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 type Error = ::juniper::FieldError<#scalar>;
@@ -660,8 +658,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::ToInputValue<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::ToInputValue<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 fn to_input_value(&self) -> ::juniper::InputValue<#scalar> {
@@ -694,23 +692,23 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const NAME: ::juniper::macros::reflect::Type = #name;
             }
 
-            impl#impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Types =
                     &[<Self as ::juniper::macros::reflect::BaseType<#scalar>>::NAME];
             }
 
-            impl#impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
-                for #ident#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
+                for #ident #ty_generics
                 #where_clause
             {
                 const VALUE: ::juniper::macros::reflect::WrappedValue = 1;
@@ -751,14 +749,14 @@ impl Definition {
                 let mut generics = self.generics.clone();
                 for lt in generics.lifetimes_mut() {
                     let ident = lt.lifetime.ident.unraw();
-                    lt.lifetime.ident = format_ident!("__fa__{}", ident);
+                    lt.lifetime.ident = format_ident!("__fa__{ident}");
                 }
 
                 let lifetimes = generics.lifetimes().map(|lt| &lt.lifetime);
                 let ident = &self.ident;
                 let (_, ty_generics, _) = generics.split_for_impl();
 
-                quote! { for<#( #lifetimes ),*> #ident#ty_generics }
+                quote! { for<#( #lifetimes ),*> #ident #ty_generics }
             } else {
                 quote! { Self }
             };
diff --git a/juniper_codegen/src/graphql_interface/attr.rs b/juniper_codegen/src/graphql_interface/attr.rs
index e1d1f44d..634a1419 100644
--- a/juniper_codegen/src/graphql_interface/attr.rs
+++ b/juniper_codegen/src/graphql_interface/attr.rs
@@ -132,7 +132,7 @@ fn expand_on_trait(
             .map(SpanContainer::into_inner)
             .collect(),
         suppress_dead_code: None,
-        src_intra_doc_link: format!("trait@{}", trait_ident).into_boxed_str(),
+        src_intra_doc_link: format!("trait@{trait_ident}").into_boxed_str(),
     };
 
     Ok(quote! {
@@ -313,7 +313,7 @@ fn expand_on_derive_input(
             .map(SpanContainer::into_inner)
             .collect(),
         suppress_dead_code: None,
-        src_intra_doc_link: format!("struct@{}", struct_ident).into_boxed_str(),
+        src_intra_doc_link: format!("struct@{struct_ident}").into_boxed_str(),
     };
 
     Ok(quote! {
diff --git a/juniper_codegen/src/graphql_interface/derive.rs b/juniper_codegen/src/graphql_interface/derive.rs
index 09d1851d..25bc096b 100644
--- a/juniper_codegen/src/graphql_interface/derive.rs
+++ b/juniper_codegen/src/graphql_interface/derive.rs
@@ -105,7 +105,7 @@ pub fn expand(input: TokenStream) -> syn::Result<TokenStream> {
             .map(SpanContainer::into_inner)
             .collect(),
         suppress_dead_code: Some((ast.ident.clone(), data.fields.clone())),
-        src_intra_doc_link: format!("struct@{}", struct_ident).into_boxed_str(),
+        src_intra_doc_link: format!("struct@{struct_ident}").into_boxed_str(),
     }
     .into_token_stream())
 }
diff --git a/juniper_codegen/src/graphql_interface/mod.rs b/juniper_codegen/src/graphql_interface/mod.rs
index 885dc9eb..afb856e1 100644
--- a/juniper_codegen/src/graphql_interface/mod.rs
+++ b/juniper_codegen/src/graphql_interface/mod.rs
@@ -5,7 +5,7 @@
 pub mod attr;
 pub mod derive;
 
-use std::{collections::HashSet, convert::TryInto as _};
+use std::collections::HashSet;
 
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote, quote_spanned, ToTokens};
@@ -39,10 +39,10 @@ fn enum_idents(
 ) -> (syn::Ident, syn::Ident) {
     let enum_alias_ident = alias_ident
         .cloned()
-        .unwrap_or_else(|| format_ident!("{}Value", trait_ident.to_string()));
+        .unwrap_or_else(|| format_ident!("{trait_ident}Value"));
     let enum_ident = alias_ident.map_or_else(
-        || format_ident!("{}ValueEnum", trait_ident.to_string()),
-        |c| format_ident!("{}Enum", c.to_string()),
+        || format_ident!("{trait_ident}ValueEnum"),
+        |c| format_ident!("{c}Enum"),
     );
     (enum_ident, enum_alias_ident)
 }
@@ -382,7 +382,7 @@ impl Definition {
         let alias_ident = &self.enum_alias_ident;
 
         let variant_gens_pars = (0..self.implemented_for.len()).map::<syn::GenericParam, _>(|id| {
-            let par = format_ident!("__I{}", id);
+            let par = format_ident!("__I{id}");
             parse_quote! { #par }
         });
         let variants_idents = self
@@ -474,8 +474,8 @@ impl Definition {
             .map(|(ty, ident)| {
                 quote! {
                     #[automatically_derived]
-                    impl#interface_impl_gens ::std::convert::From<#ty>
-                        for #alias_ident#interface_ty_gens
+                    impl #interface_impl_gens ::std::convert::From<#ty>
+                        for #alias_ident #interface_ty_gens
                         #interface_where_clause
                     {
                         fn from(v: #ty) -> Self {
@@ -489,14 +489,14 @@ impl Definition {
             #[automatically_derived]
             #[derive(Clone, Copy, Debug)]
             #[doc = #enum_doc]
-            #vis enum #enum_ident#enum_gens {
+            #vis enum #enum_ident #enum_gens {
                 #( #[doc(hidden)] #variants_idents(#variant_gens_pars), )*
                 #( #[doc(hidden)] #phantom_variant, )*
             }
 
             #[automatically_derived]
             #[doc = #enum_alias_doc]
-            #vis type #alias_ident#enum_alias_gens =
+            #vis type #alias_ident #enum_alias_gens =
                 #enum_ident<#( #enum_to_alias_gens ),*>;
 
             #( #from_impls )*
@@ -523,7 +523,7 @@ impl Definition {
 
             quote! {{
                 const SUPPRESS_DEAD_CODE: () = {
-                    let none = Option::<#ident#const_gens>::None;
+                    let none = Option::<#ident #const_gens>::None;
                     match none {
                         Some(unreachable) => {
                             #( let _ = unreachable.#fields; )*
@@ -580,8 +580,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::GraphQLInterface<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::marker::GraphQLInterface<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 fn mark() {
@@ -637,7 +637,7 @@ impl Definition {
             quote_spanned! { const_impl_for.span() =>
                 ::juniper::assert_transitive_impls!(
                     #const_scalar,
-                    #ty#ty_const_generics,
+                    #ty #ty_const_generics,
                     #const_impl_for,
                     #( #const_implements ),*
                 );
@@ -646,8 +646,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsOutputType<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::marker::IsOutputType<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 fn mark() {
@@ -655,12 +655,12 @@ impl Definition {
                     #( #is_output )*
                     ::juniper::assert_interfaces_impls!(
                         #const_scalar,
-                        #ty#ty_const_generics,
+                        #ty #ty_const_generics,
                         #( #const_impl_for ),*
                     );
                     ::juniper::assert_implemented_for!(
                         #const_scalar,
-                        #ty#ty_const_generics,
+                        #ty #ty_const_generics,
                         #( #const_implements ),*
                     );
                     #( #transitive_checks )*
@@ -711,8 +711,8 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLType<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::GraphQLType<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 fn name(_ : &Self::TypeInfo) -> Option<&'static str> {
@@ -731,7 +731,7 @@ impl Definition {
                     let fields = [
                         #( #fields_meta, )*
                     ];
-                    registry.build_interface_type::<#ty#ty_generics>(info, &fields)
+                    registry.build_interface_type::<#ty #ty_generics>(info, &fields)
                         #description
                         #impl_interfaces
                         .into_meta()
@@ -778,7 +778,7 @@ impl Definition {
         quote! {
             #[allow(deprecated)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValue<#scalar> for #ty#ty_generics
+            impl #impl_generics ::juniper::GraphQLValue<#scalar> for #ty #ty_generics
                 #where_clause
             {
                 type Context = #context;
@@ -856,7 +856,7 @@ impl Definition {
         quote! {
             #[allow(deprecated, non_snake_case)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty#ty_generics
+            impl #impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty #ty_generics
                 #where_clause
             {
                 fn resolve_field_async<'b>(
@@ -908,16 +908,16 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseType<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseType<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 const NAME: ::juniper::macros::reflect::Type = #name;
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Types = &[
@@ -927,8 +927,8 @@ impl Definition {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::Implements<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::Implements<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Types =
@@ -936,16 +936,16 @@ impl Definition {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 const VALUE: ::juniper::macros::reflect::WrappedValue = 1;
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::Fields<#scalar>
-                for #ty#ty_generics
+            impl #impl_generics ::juniper::macros::reflect::Fields<#scalar>
+                for #ty #ty_generics
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Names = &[#(#fields),*];
@@ -987,10 +987,10 @@ impl Definition {
                 quote! {
                     #[allow(non_snake_case)]
                     #[automatically_derived]
-                    impl#impl_generics ::juniper::macros::reflect::FieldMeta<
+                    impl #impl_generics ::juniper::macros::reflect::FieldMeta<
                         #scalar,
                         { ::juniper::macros::reflect::fnv1a128(#field_name) }
-                    > for #ty#ty_generics #where_clause {
+                    > for #ty #ty_generics #where_clause {
                         type Context = #context;
                         type TypeInfo = ();
                         const TYPE: ::juniper::macros::reflect::Type =
@@ -1061,10 +1061,10 @@ impl Definition {
                 quote_spanned! { field.ident.span() =>
                     #[allow(non_snake_case)]
                     #[automatically_derived]
-                    impl#impl_generics ::juniper::macros::reflect::Field<
+                    impl #impl_generics ::juniper::macros::reflect::Field<
                         #scalar,
                         { ::juniper::macros::reflect::fnv1a128(#field_name) }
-                    > for #ty#ty_generics #where_clause {
+                    > for #ty #ty_generics #where_clause {
                         fn call(
                             &self,
                             info: &Self::TypeInfo,
@@ -1074,7 +1074,7 @@ impl Definition {
                             match self {
                                 #( #ty::#implemented_for_idents(v) => {
                                     ::juniper::assert_field!(
-                                        #ty#const_ty_generics,
+                                        #ty #const_ty_generics,
                                         #const_implemented_for,
                                         #const_scalar,
                                         #field_name,
@@ -1141,10 +1141,10 @@ impl Definition {
                 quote_spanned! { field.ident.span() =>
                     #[allow(non_snake_case)]
                     #[automatically_derived]
-                    impl#impl_generics ::juniper::macros::reflect::AsyncField<
+                    impl #impl_generics ::juniper::macros::reflect::AsyncField<
                         #scalar,
                         { ::juniper::macros::reflect::fnv1a128(#field_name) }
-                    > for #ty#ty_generics #where_clause {
+                    > for #ty #ty_generics #where_clause {
                         fn call<'b>(
                             &'b self,
                             info: &'b Self::TypeInfo,
@@ -1154,7 +1154,7 @@ impl Definition {
                             match self {
                                 #( #ty::#implemented_for_idents(v) => {
                                     ::juniper::assert_field!(
-                                        #ty#const_ty_generics,
+                                        #ty #const_ty_generics,
                                         #const_implemented_for,
                                         #const_scalar,
                                         #field_name,
@@ -1346,14 +1346,14 @@ impl Definition {
                 let mut generics = self.generics.clone();
                 for lt in generics.lifetimes_mut() {
                     let ident = lt.lifetime.ident.unraw();
-                    lt.lifetime.ident = format_ident!("__fa__{}", ident);
+                    lt.lifetime.ident = format_ident!("__fa__{ident}");
                 }
 
                 let lifetimes = generics.lifetimes().map(|lt| &lt.lifetime);
                 let ty = &self.enum_alias_ident;
                 let (_, ty_generics, _) = generics.split_for_impl();
 
-                quote! { for<#( #lifetimes ),*> #ty#ty_generics }
+                quote! { for<#( #lifetimes ),*> #ty #ty_generics }
             } else {
                 quote! { Self }
             };
diff --git a/juniper_codegen/src/graphql_object/attr.rs b/juniper_codegen/src/graphql_object/attr.rs
index 0c4c7c05..37b47d16 100644
--- a/juniper_codegen/src/graphql_object/attr.rs
+++ b/juniper_codegen/src/graphql_object/attr.rs
@@ -188,7 +188,7 @@ fn parse_field(
                 }
                 syn::FnArg::Typed(arg) => {
                     if let syn::Pat::Ident(a) = &*arg.pat {
-                        if a.ident.to_string().as_str() == "self" {
+                        if a.ident == "self" {
                             return err_invalid_method_receiver(arg);
                         }
                     }
diff --git a/juniper_codegen/src/graphql_object/derive.rs b/juniper_codegen/src/graphql_object/derive.rs
index f4e75b4e..189ed261 100644
--- a/juniper_codegen/src/graphql_object/derive.rs
+++ b/juniper_codegen/src/graphql_object/derive.rs
@@ -34,7 +34,7 @@ fn expand_struct(ast: syn::DeriveInput) -> syn::Result<Definition<Query>> {
     let struct_ident = ast.ident;
 
     let (_, struct_generics, _) = ast.generics.split_for_impl();
-    let ty = parse_quote! { #struct_ident#struct_generics };
+    let ty = parse_quote! { #struct_ident #struct_generics };
 
     let name = attr
         .name
diff --git a/juniper_codegen/src/graphql_object/mod.rs b/juniper_codegen/src/graphql_object/mod.rs
index df4d3a32..facc7300 100644
--- a/juniper_codegen/src/graphql_object/mod.rs
+++ b/juniper_codegen/src/graphql_object/mod.rs
@@ -5,7 +5,7 @@
 pub mod attr;
 pub mod derive;
 
-use std::{any::TypeId, collections::HashSet, convert::TryInto as _, marker::PhantomData};
+use std::{any::TypeId, collections::HashSet, marker::PhantomData};
 
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
@@ -299,7 +299,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
                 let mut ty = self.ty.clone();
                 ty.lifetimes_iter_mut(&mut |lt| {
                     let ident = lt.ident.unraw();
-                    lt.ident = format_ident!("__fa__{}", ident);
+                    lt.ident = format_ident!("__fa__{ident}");
                     lifetimes.push(lt.clone());
                 });
 
@@ -346,7 +346,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsOutputType<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::marker::IsOutputType<#scalar> for #ty #where_clause
             {
                 fn mark() {
                     #( #fields_marks )*
@@ -375,7 +375,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseType<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::BaseType<#scalar>
                 for #ty
                 #where_clause
             {
@@ -383,7 +383,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
                 for #ty
                 #where_clause
             {
@@ -392,7 +392,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::Implements<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::Implements<#scalar>
                 for #ty
                 #where_clause
             {
@@ -401,7 +401,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
                 for #ty
                 #where_clause
             {
@@ -409,7 +409,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::Fields<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::Fields<#scalar>
                 for #ty
                 #where_clause
             {
@@ -437,7 +437,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
         let fields_meta = self
             .fields
             .iter()
-            .map(|f| f.method_meta_tokens(extract_stream_type.then(|| scalar)));
+            .map(|f| f.method_meta_tokens(extract_stream_type.then_some(scalar)));
 
         // Sorting is required to preserve/guarantee the order of interfaces registered in schema.
         let mut interface_tys: Vec<_> = self.interfaces.iter().collect();
@@ -455,7 +455,7 @@ impl<Operation: ?Sized + 'static> Definition<Operation> {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLType<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::GraphQLType<#scalar> for #ty #where_clause
             {
                 fn name(_ : &Self::TypeInfo) -> Option<&'static str> {
                     Some(#name)
@@ -536,7 +536,7 @@ impl Definition<Query> {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::GraphQLObject<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::marker::GraphQLObject<#scalar> for #ty #where_clause
             {
                 fn mark() {
                     #( <#interface_tys as ::juniper::marker::GraphQLInterface<#scalar>>::mark(); )*
@@ -778,7 +778,7 @@ impl Definition<Query> {
         quote! {
             #[allow(deprecated)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValue<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::GraphQLValue<#scalar> for #ty #where_clause
             {
                 type Context = #context;
                 type TypeInfo = ();
@@ -805,7 +805,7 @@ impl Definition<Query> {
                     _: &Self::Context,
                     _: &Self::TypeInfo,
                 ) -> String {
-                    #name.to_string()
+                    #name.into()
                 }
             }
         }
@@ -842,7 +842,7 @@ impl Definition<Query> {
         quote! {
             #[allow(deprecated, non_snake_case)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty #where_clause
             {
                 fn resolve_field_async<'b>(
                     &'b self,
diff --git a/juniper_codegen/src/graphql_scalar/mod.rs b/juniper_codegen/src/graphql_scalar/mod.rs
index d0758e75..2280d9c2 100644
--- a/juniper_codegen/src/graphql_scalar/mod.rs
+++ b/juniper_codegen/src/graphql_scalar/mod.rs
@@ -119,7 +119,7 @@ impl Parse for Attr {
                     input.parse::<token::Eq>()?;
                     let lit = input.parse::<syn::LitStr>()?;
                     let url = lit.value().parse::<Url>().map_err(|err| {
-                        syn::Error::new(lit.span(), format!("Invalid URL: {}", err))
+                        syn::Error::new(lit.span(), format!("Invalid URL: {err}"))
                     })?;
                     out.specified_by_url
                         .replace(SpanContainer::new(ident.span(), Some(lit.span()), url))
@@ -343,11 +343,11 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::marker::IsInputType<#scalar> for #ty
+            impl #impl_gens ::juniper::marker::IsInputType<#scalar> for #ty
                 #where_clause { }
 
             #[automatically_derived]
-            impl#impl_gens ::juniper::marker::IsOutputType<#scalar> for #ty
+            impl #impl_gens ::juniper::marker::IsOutputType<#scalar> for #ty
                 #where_clause { }
         }
     }
@@ -372,7 +372,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::GraphQLType<#scalar> for #ty
+            impl #impl_gens ::juniper::GraphQLType<#scalar> for #ty
                 #where_clause
             {
                 fn name(_: &Self::TypeInfo) -> Option<&'static str> {
@@ -410,7 +410,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::GraphQLValue<#scalar> for #ty
+            impl #impl_gens ::juniper::GraphQLValue<#scalar> for #ty
                 #where_clause
             {
                 type Context = ();
@@ -445,7 +445,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::GraphQLValueAsync<#scalar> for #ty
+            impl #impl_gens ::juniper::GraphQLValueAsync<#scalar> for #ty
                 #where_clause
             {
                 fn resolve_async<'b>(
@@ -477,7 +477,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::ToInputValue<#scalar> for #ty
+            impl #impl_gens ::juniper::ToInputValue<#scalar> for #ty
                 #where_clause
             {
                 fn to_input_value(&self) -> ::juniper::InputValue<#scalar> {
@@ -502,7 +502,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::FromInputValue<#scalar> for #ty
+            impl #impl_gens ::juniper::FromInputValue<#scalar> for #ty
                 #where_clause
             {
                 type Error = ::juniper::executor::FieldError<#scalar>;
@@ -530,7 +530,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::ParseScalarValue<#scalar> for #ty
+            impl #impl_gens ::juniper::ParseScalarValue<#scalar> for #ty
                 #where_clause
             {
                 fn from_str(
@@ -558,14 +558,14 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::macros::reflect::BaseType<#scalar> for #ty
+            impl #impl_gens ::juniper::macros::reflect::BaseType<#scalar> for #ty
                 #where_clause
             {
                 const NAME: ::juniper::macros::reflect::Type = #name;
             }
 
             #[automatically_derived]
-            impl#impl_gens ::juniper::macros::reflect::BaseSubTypes<#scalar> for #ty
+            impl #impl_gens ::juniper::macros::reflect::BaseSubTypes<#scalar> for #ty
                 #where_clause
             {
                 const NAMES: ::juniper::macros::reflect::Types =
@@ -573,7 +573,7 @@ impl Definition {
             }
 
             #[automatically_derived]
-            impl#impl_gens ::juniper::macros::reflect::WrappedType<#scalar> for #ty
+            impl #impl_gens ::juniper::macros::reflect::WrappedType<#scalar> for #ty
                 #where_clause
             {
                 const VALUE: ::juniper::macros::reflect::WrappedValue = 1;
@@ -597,7 +597,7 @@ impl Definition {
             TypeOrIdent::Type(ty) => ty.into_token_stream(),
             TypeOrIdent::Ident(ident) => {
                 let (_, ty_gen, _) = self.generics.split_for_impl();
-                quote! { #ident#ty_gen }
+                quote! { #ident #ty_gen }
             }
         };
 
@@ -635,7 +635,7 @@ impl Definition {
                     }
                     TypeOrIdent::Ident(ident) => {
                         let (_, ty_gens, _) = generics.split_for_impl();
-                        quote! { #ident#ty_gens }
+                        quote! { #ident #ty_gens }
                     }
                 };
 
diff --git a/juniper_codegen/src/graphql_subscription/mod.rs b/juniper_codegen/src/graphql_subscription/mod.rs
index a326e52d..c8d2fb42 100644
--- a/juniper_codegen/src/graphql_subscription/mod.rs
+++ b/juniper_codegen/src/graphql_subscription/mod.rs
@@ -44,7 +44,7 @@ impl Definition<Subscription> {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValue<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::GraphQLValue<#scalar> for #ty #where_clause
             {
                 type Context = #context;
                 type TypeInfo = ();
@@ -70,7 +70,7 @@ impl Definition<Subscription> {
                     _: &Self::Context,
                     _: &Self::TypeInfo,
                 ) -> String {
-                    #name.to_string()
+                    #name.into()
                 }
             }
         }
@@ -109,7 +109,7 @@ impl Definition<Subscription> {
         quote! {
             #[allow(deprecated)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLSubscriptionValue<#scalar> for #ty #where_clause
+            impl #impl_generics ::juniper::GraphQLSubscriptionValue<#scalar> for #ty #where_clause
             {
                 fn resolve_field_into_stream<
                     's, 'i, 'fi, 'args, 'e, 'ref_e, 'res, 'f,
diff --git a/juniper_codegen/src/graphql_union/attr.rs b/juniper_codegen/src/graphql_union/attr.rs
index 733cfc99..006ad226 100644
--- a/juniper_codegen/src/graphql_union/attr.rs
+++ b/juniper_codegen/src/graphql_union/attr.rs
@@ -173,10 +173,9 @@ fn parse_variant_from_trait_method(
             ERR.custom(
                 method_span,
                 format!(
-                    "trait method `{}` conflicts with the external resolver \
-                     function `{}` declared on the trait to resolve the \
-                     variant type `{}`",
-                    method_ident,
+                    "trait method `{method_ident}` conflicts with the external \
+                     resolver function `{}` declared on the trait to resolve \
+                     the variant type `{}`",
                     other.to_token_stream(),
                     ty.to_token_stream(),
                 ),
diff --git a/juniper_codegen/src/graphql_union/mod.rs b/juniper_codegen/src/graphql_union/mod.rs
index e49f0fbf..fa585b00 100644
--- a/juniper_codegen/src/graphql_union/mod.rs
+++ b/juniper_codegen/src/graphql_union/mod.rs
@@ -336,7 +336,7 @@ impl Definition {
         let (_, ty_generics, _) = self.generics.split_for_impl();
         let ty = &self.ty;
 
-        let mut ty_full = quote! { #ty#ty_generics };
+        let mut ty_full = quote! { #ty #ty_generics };
         if self.is_trait_object {
             ty_full = quote! { dyn #ty_full + '__obj + Send + Sync };
         }
@@ -368,14 +368,14 @@ impl Definition {
                 let mut generics = self.generics.clone();
                 for lt in generics.lifetimes_mut() {
                     let ident = lt.lifetime.ident.unraw();
-                    lt.lifetime.ident = format_ident!("__fa__{}", ident);
+                    lt.lifetime.ident = format_ident!("__fa__{ident}");
                 }
 
                 let lifetimes = generics.lifetimes().map(|lt| &lt.lifetime);
                 let ty = &self.ty;
                 let (_, ty_generics, _) = generics.split_for_impl();
 
-                quote! { for<#( #lifetimes ),*> #ty#ty_generics }
+                quote! { for<#( #lifetimes ),*> #ty #ty_generics }
             } else {
                 quote! { Self }
             };
@@ -418,7 +418,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::GraphQLUnion<#scalar> for #ty_full #where_clause
+            impl #impl_generics ::juniper::marker::GraphQLUnion<#scalar> for #ty_full #where_clause
             {
                 fn mark() {
                     #all_variants_unique
@@ -443,7 +443,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::marker::IsOutputType<#scalar> for #ty_full #where_clause
+            impl #impl_generics ::juniper::marker::IsOutputType<#scalar> for #ty_full #where_clause
             {
                 fn mark() {
                     #( <#variant_tys as ::juniper::marker::IsOutputType<#scalar>>::mark(); )*
@@ -470,7 +470,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLType<#scalar> for #ty_full #where_clause
+            impl #impl_generics ::juniper::GraphQLType<#scalar> for #ty_full #where_clause
             {
                 fn name(_ : &Self::TypeInfo) -> Option<&'static str> {
                     Some(#name)
@@ -519,7 +519,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValue<#scalar> for #ty_full #where_clause
+            impl #impl_generics ::juniper::GraphQLValue<#scalar> for #ty_full #where_clause
             {
                 type Context = #context;
                 type TypeInfo = ();
@@ -534,7 +534,7 @@ impl Definition {
                     info: &Self::TypeInfo,
                 ) -> String {
                     #( #match_variant_names )*
-                    panic!(
+                    ::std::panic!(
                         "GraphQL union `{}` cannot be resolved into any of its \
                          variants in its current state",
                         #name,
@@ -550,7 +550,7 @@ impl Definition {
                 ) -> ::juniper::ExecutionResult<#scalar> {
                     let context = executor.context();
                     #( #variant_resolvers )*
-                    return Err(::juniper::FieldError::from(format!(
+                    return Err(::juniper::FieldError::from(::std::format!(
                         "Concrete type `{}` is not handled by instance \
                          resolvers on GraphQL union `{}`",
                         type_name, #name,
@@ -581,7 +581,7 @@ impl Definition {
         quote! {
             #[allow(non_snake_case)]
             #[automatically_derived]
-            impl#impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty_full #where_clause
+            impl #impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ty_full #where_clause
             {
                 fn resolve_into_type_async<'b>(
                     &'b self,
@@ -592,7 +592,7 @@ impl Definition {
                 ) -> ::juniper::BoxFuture<'b, ::juniper::ExecutionResult<#scalar>> {
                     let context = executor.context();
                     #( #variant_async_resolvers )*
-                    return ::juniper::macros::helper::err_fut(format!(
+                    return ::juniper::macros::helper::err_fut(::std::format!(
                         "Concrete type `{}` is not handled by instance \
                          resolvers on GraphQL union `{}`",
                         type_name, #name,
@@ -618,7 +618,7 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseType<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::BaseType<#scalar>
                 for #ty
                 #where_clause
             {
@@ -626,7 +626,7 @@ impl Definition {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::BaseSubTypes<#scalar>
                 for #ty
                 #where_clause
             {
@@ -637,7 +637,7 @@ impl Definition {
             }
 
             #[automatically_derived]
-            impl#impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
+            impl #impl_generics ::juniper::macros::reflect::WrappedType<#scalar>
                 for #ty
                 #where_clause
             {
diff --git a/juniper_codegen/src/lib.rs b/juniper_codegen/src/lib.rs
index d77a21b5..d88488c3 100644
--- a/juniper_codegen/src/lib.rs
+++ b/juniper_codegen/src/lib.rs
@@ -440,18 +440,17 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///     ) -> Result<Self, String> {
 ///         //            ^^^^^^ must implement `IntoFieldError`
 ///         input.as_string_value()
-///             .ok_or_else(|| format!("Expected `String`, found: {}", input))
+///             .ok_or_else(|| format!("Expected `String`, found: {input}"))
 ///             .and_then(|str| {
 ///                 str.strip_prefix("id: ")
 ///                     .ok_or_else(|| {
 ///                         format!(
 ///                             "Expected `UserId` to begin with `id: `, \
-///                              found: {}",
-///                             input,
+///                              found: {input}",
 ///                         )
 ///                     })
 ///             })
-///             .map(|id| Self(id.to_owned()))
+///             .map(|id| Self(id.into()))
 ///     }
 /// }
 /// ```
@@ -483,16 +482,16 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///
 /// fn to_output<S: ScalarValue>(v: &StringOrInt) -> Value<S> {
 ///     match v {
-///         StringOrInt::String(str) => Value::scalar(str.to_owned()),
+///         StringOrInt::String(s) => Value::scalar(s.to_owned()),
 ///         StringOrInt::Int(i) => Value::scalar(*i),
 ///     }
 /// }
 ///
 /// fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<StringOrInt, String> {
 ///     v.as_string_value()
-///         .map(|s| StringOrInt::String(s.to_owned()))
+///         .map(|s| StringOrInt::String(s.into()))
 ///         .or_else(|| v.as_int_value().map(StringOrInt::Int))
-///         .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+///         .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
 /// }
 ///
 /// fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -526,16 +525,16 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///
 ///     pub(super) fn to_output<S: ScalarValue>(v: &StringOrInt) -> Value<S> {
 ///         match v {
-///             StringOrInt::String(str) => Value::scalar(str.to_owned()),
+///             StringOrInt::String(s) => Value::scalar(s.to_owned()),
 ///             StringOrInt::Int(i) => Value::scalar(*i),
 ///         }
 ///     }
 ///
 ///     pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<StringOrInt, String> {
 ///         v.as_string_value()
-///             .map(|s| StringOrInt::String(s.to_owned()))
+///             .map(|s| StringOrInt::String(s.into()))
 ///             .or_else(|| v.as_int_value().map(StringOrInt::Int))
-///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
 ///     }
 ///
 ///     pub(super) fn parse_token<S: ScalarValue>(t: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -564,7 +563,7 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 /// impl StringOrInt {
 ///     fn to_output<S: ScalarValue>(&self) -> Value<S> {
 ///         match self {
-///             Self::String(str) => Value::scalar(str.to_owned()),
+///             Self::String(s) => Value::scalar(s.to_owned()),
 ///             Self::Int(i) => Value::scalar(*i),
 ///         }
 ///     }
@@ -574,9 +573,9 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///         S: ScalarValue
 ///     {
 ///         v.as_string_value()
-///             .map(|s| Self::String(s.to_owned()))
+///             .map(|s| Self::String(s.into()))
 ///             .or_else(|| v.as_int_value().map(Self::Int))
-///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
 ///     }
 ///
 ///     fn parse_token<S>(value: ScalarToken<'_>) -> ParseScalarResult<S>
@@ -616,7 +615,7 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///         S: ScalarValue,
 ///     {
 ///         match v {
-///             StringOrInt::String(str) => Value::scalar(str.to_owned()),
+///             StringOrInt::String(s) => Value::scalar(s.to_owned()),
 ///             StringOrInt::Int(i) => Value::scalar(*i),
 ///         }
 ///     }
@@ -626,9 +625,9 @@ pub fn derive_enum(input: TokenStream) -> TokenStream {
 ///         S: ScalarValue,
 ///     {
 ///         v.as_string_value()
-///             .map(|s| StringOrInt::String(s.to_owned()))
+///             .map(|s| StringOrInt::String(s.into()))
 ///             .or_else(|| v.as_int_value().map(StringOrInt::Int))
-///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+///             .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
 ///     }
 ///
 ///     // No need in `parse_token()` function.
@@ -736,8 +735,8 @@ pub fn derive_scalar(input: TokenStream) -> TokenStream {
 ///
 ///     pub(super) fn from_input(v: &InputValue<CustomScalarValue>) -> Result<Date, String> {
 ///       v.as_string_value()
-///           .ok_or_else(|| format!("Expected `String`, found: {}", v))
-///           .and_then(|s| s.parse().map_err(|e| format!("Failed to parse `Date`: {}", e)))
+///           .ok_or_else(|| format!("Expected `String`, found: {v}"))
+///           .and_then(|s| s.parse().map_err(|e| format!("Failed to parse `Date`: {e}")))
 ///     }
 /// }
 /// #
@@ -766,7 +765,7 @@ pub fn graphql_scalar(attr: TokenStream, body: TokenStream) -> TokenStream {
 /// methods).
 ///
 /// ```rust
-/// # use std::{fmt, convert::TryInto as _};
+/// # use std::fmt;
 /// #
 /// # use serde::{de, Deserialize, Deserializer, Serialize};
 /// # use juniper::ScalarValue;
@@ -1129,7 +1128,7 @@ pub fn derive_scalar_value(input: TokenStream) -> TokenStream {
 ///     // You can return `&str` even if trait definition returns `String`.
 ///     fn detailed_info(&self, info_kind: String) -> &str {
 ///         (info_kind == "planet")
-///             .then(|| &self.home_planet)
+///             .then_some(&self.home_planet)
 ///             .unwrap_or(&self.id)
 ///     }
 /// }
diff --git a/juniper_codegen/src/scalar_value/mod.rs b/juniper_codegen/src/scalar_value/mod.rs
index fe9aa6de..e0a0d78b 100644
--- a/juniper_codegen/src/scalar_value/mod.rs
+++ b/juniper_codegen/src/scalar_value/mod.rs
@@ -1,6 +1,6 @@
 //! Code generation for `#[derive(ScalarValue)]` macro.
 
-use std::{collections::HashMap, convert::TryFrom};
+use std::collections::HashMap;
 
 use proc_macro2::{Literal, TokenStream};
 use quote::{quote, ToTokens, TokenStreamExt as _};
@@ -55,11 +55,11 @@ pub fn expand_derive(input: TokenStream) -> syn::Result<TokenStream> {
         (Method::AsBool, "as_bool"),
     ]
     .iter()
-    .filter_map(|(method, err)| (!methods.contains_key(method)).then(|| err))
+    .filter_map(|(method, err)| (!methods.contains_key(method)).then_some(err))
     .fold(None, |acc, &method| {
         Some(
-            acc.map(|acc| format!("{}, {}", acc, method))
-                .unwrap_or_else(|| method.to_owned()),
+            acc.map(|acc| format!("{acc}, {method}"))
+                .unwrap_or_else(|| method.into()),
         )
     })
     .filter(|_| !attr.allow_missing_attrs);
@@ -67,10 +67,9 @@ pub fn expand_derive(input: TokenStream) -> syn::Result<TokenStream> {
         return Err(ERR.custom_error(
             span,
             format!(
-                "missing `#[value({})]` attributes. In case you are sure \
-                 that it's ok, use `#[value(allow_missing_attributes)]` to \
-                 suppress this error.",
-                missing_methods,
+                "missing `#[value({missing_methods})]` attributes. In case you \
+                 are sure that it's ok, use `#[value(allow_missing_attributes)]` \
+                 to suppress this error.",
             ),
         ));
     }
@@ -298,10 +297,10 @@ impl Definition {
 
         quote! {
             #[automatically_derived]
-            impl#impl_gens ::juniper::ScalarValue for #ident#ty_gens
+            impl #impl_gens ::juniper::ScalarValue for #ident #ty_gens
                 #where_clause
             {
-                #(#methods)*
+                #( #methods )*
             }
         }
     }
@@ -333,20 +332,20 @@ impl Definition {
 
                 quote! {
                     #[automatically_derived]
-                    impl#impl_gen ::std::convert::From<#var_ty> for #ty_ident#ty_gen
+                    impl #impl_gen ::std::convert::From<#var_ty> for #ty_ident #ty_gen
                         #where_clause
                     {
                         fn from(v: #var_ty) -> Self {
-                            Self::#var_ident#var_field
+                            Self::#var_ident #var_field
                         }
                     }
 
                     #[automatically_derived]
-                    impl#impl_gen ::std::convert::From<#ty_ident#ty_gen> for Option<#var_ty>
+                    impl #impl_gen ::std::convert::From<#ty_ident #ty_gen> for Option<#var_ty>
                         #where_clause
                     {
-                        fn from(ty: #ty_ident#ty_gen) -> Self {
-                            if let #ty_ident::#var_ident#var_field = ty {
+                        fn from(ty: #ty_ident #ty_gen) -> Self {
+                            if let #ty_ident::#var_ident #var_field = ty {
                                 Some(v)
                             } else {
                                 None
@@ -355,12 +354,12 @@ impl Definition {
                     }
 
                     #[automatically_derived]
-                    impl#lf_impl_gen ::std::convert::From<&'___a #ty_ident#ty_gen> for
+                    impl #lf_impl_gen ::std::convert::From<&'___a #ty_ident #ty_gen> for
                         Option<&'___a #var_ty>
                         #where_clause
                     {
-                        fn from(ty: &'___a #ty_ident#ty_gen) -> Self {
-                            if let #ty_ident::#var_ident#var_field = ty {
+                        fn from(ty: &'___a #ty_ident #ty_gen) -> Self {
+                            if let #ty_ident::#var_ident #var_field = ty {
                                 Some(v)
                             } else {
                                 None
@@ -404,17 +403,17 @@ impl Definition {
                 .as_ref()
                 .map_or_else(|| quote! { (v) }, |i| quote! { { #i: v } });
 
-            quote! { Self::#var_ident#var_field => ::std::fmt::Display::fmt(v, f), }
+            quote! { Self::#var_ident #var_field => ::std::fmt::Display::fmt(v, f), }
         });
 
         quote! {
             #[automatically_derived]
-            impl#impl_gen ::std::fmt::Display for #ident#ty_gen
+            impl #impl_gen ::std::fmt::Display for #ident #ty_gen
                 #where_clause
             {
                 fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
                     match self {
-                        #(#arms)*
+                        #( #arms )*
                     }
                 }
             }
@@ -440,7 +439,7 @@ impl Variant {
     fn match_arm(&self) -> TokenStream {
         let (ident, field) = (&self.ident, &self.field.match_arg());
         quote! {
-            Self::#ident#field
+            Self::#ident #field
         }
     }
 }
diff --git a/juniper_graphql_ws/Cargo.toml b/juniper_graphql_ws/Cargo.toml
index 3b74f4bb..c8b68806 100644
--- a/juniper_graphql_ws/Cargo.toml
+++ b/juniper_graphql_ws/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_graphql_ws"
 version = "0.4.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "GraphQL over WebSocket Protocol implementation for `juniper` crate."
 license = "BSD-2-Clause"
 authors = ["Christopher Brown <ccbrown112@gmail.com>"]
diff --git a/juniper_graphql_ws/src/client_message.rs b/juniper_graphql_ws/src/client_message.rs
index c893f6da..767f6969 100644
--- a/juniper_graphql_ws/src/client_message.rs
+++ b/juniper_graphql_ws/src/client_message.rs
@@ -78,11 +78,11 @@ mod test {
 
         assert_eq!(
             ClientMessage::Start {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: StartPayload {
-                    query: "query MyQuery { __typename }".to_string(),
+                    query: "query MyQuery { __typename }".into(),
                     variables: graphql_vars! {"foo": "bar"},
-                    operation_name: Some("MyQuery".to_string()),
+                    operation_name: Some("MyQuery".into()),
                 },
             },
             serde_json::from_str(
@@ -99,9 +99,9 @@ mod test {
 
         assert_eq!(
             ClientMessage::Start {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: StartPayload {
-                    query: "query MyQuery { __typename }".to_string(),
+                    query: "query MyQuery { __typename }".into(),
                     variables: graphql_vars! {},
                     operation_name: None,
                 },
@@ -115,9 +115,7 @@ mod test {
         );
 
         assert_eq!(
-            ClientMessage::Stop {
-                id: "foo".to_string()
-            },
+            ClientMessage::Stop { id: "foo".into() },
             serde_json::from_str(r##"{"type": "stop", "id": "foo"}"##).unwrap(),
         );
 
diff --git a/juniper_graphql_ws/src/lib.rs b/juniper_graphql_ws/src/lib.rs
index e809c009..d1621a61 100644
--- a/juniper_graphql_ws/src/lib.rs
+++ b/juniper_graphql_ws/src/lib.rs
@@ -14,13 +14,8 @@ pub use schema::*;
 mod utils;
 
 use std::{
-    collections::HashMap,
-    convert::{Infallible, TryInto},
-    error::Error,
-    marker::PhantomPinned,
-    pin::Pin,
-    sync::Arc,
-    time::Duration,
+    collections::HashMap, convert::Infallible, error::Error, marker::PhantomPinned, pin::Pin,
+    sync::Arc, time::Duration,
 };
 
 use juniper::{
@@ -292,9 +287,10 @@ impl<S: Schema, I: Init<S::ScalarValue, S::Context>> ConnectionState<S, I> {
     }
 
     async fn start(id: String, params: ExecutionParams<S>) -> BoxStream<'static, Reaction<S>> {
-        // TODO: This could be made more efficient if juniper exposed functionality to allow us to
-        // parse and validate the query, determine whether it's a subscription, and then execute
-        // it. For now, the query gets parsed and validated twice.
+        // TODO: This could be made more efficient if `juniper` exposed
+        //       functionality to allow us to parse and validate the query,
+        //       determine whether it's a subscription, and then execute it.
+        //       For now, the query gets parsed and validated twice.
 
         let params = Arc::new(params);
 
@@ -707,9 +703,9 @@ mod test {
         assert_eq!(ServerMessage::ConnectionAck, conn.next().await.unwrap());
 
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "{context}".to_string(),
+                query: "{context}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -719,7 +715,7 @@ mod test {
 
         assert_eq!(
             ServerMessage::Data {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: DataPayload {
                     data: graphql_value!({"context": 1}),
                     errors: vec![],
@@ -729,9 +725,7 @@ mod test {
         );
 
         assert_eq!(
-            ServerMessage::Complete {
-                id: "foo".to_string(),
-            },
+            ServerMessage::Complete { id: "foo".into() },
             conn.next().await.unwrap()
         );
     }
@@ -752,9 +746,9 @@ mod test {
         assert_eq!(ServerMessage::ConnectionAck, conn.next().await.unwrap());
 
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "subscription Foo {context}".to_string(),
+                query: "subscription Foo {context}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -764,7 +758,7 @@ mod test {
 
         assert_eq!(
             ServerMessage::Data {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: DataPayload {
                     data: graphql_value!({"context": 1}),
                     errors: vec![],
@@ -774,9 +768,9 @@ mod test {
         );
 
         conn.send(ClientMessage::Start {
-            id: "bar".to_string(),
+            id: "bar".into(),
             payload: StartPayload {
-                query: "subscription Bar {context}".to_string(),
+                query: "subscription Bar {context}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -786,7 +780,7 @@ mod test {
 
         assert_eq!(
             ServerMessage::Data {
-                id: "bar".to_string(),
+                id: "bar".into(),
                 payload: DataPayload {
                     data: graphql_value!({"context": 1}),
                     errors: vec![],
@@ -795,16 +789,12 @@ mod test {
             conn.next().await.unwrap()
         );
 
-        conn.send(ClientMessage::Stop {
-            id: "foo".to_string(),
-        })
-        .await
-        .unwrap();
+        conn.send(ClientMessage::Stop { id: "foo".into() })
+            .await
+            .unwrap();
 
         assert_eq!(
-            ServerMessage::Complete {
-                id: "foo".to_string(),
-            },
+            ServerMessage::Complete { id: "foo".into() },
             conn.next().await.unwrap()
         );
     }
@@ -841,7 +831,7 @@ mod test {
         assert_eq!(
             ServerMessage::ConnectionError {
                 payload: ConnectionErrorPayload {
-                    message: "init error".to_string(),
+                    message: "init error".into(),
                 },
             },
             conn.next().await.unwrap()
@@ -866,9 +856,9 @@ mod test {
         assert_eq!(ServerMessage::ConnectionAck, conn.next().await.unwrap());
 
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "subscription Foo {never}".to_string(),
+                query: "subscription Foo {never}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -877,9 +867,9 @@ mod test {
         .unwrap();
 
         conn.send(ClientMessage::Start {
-            id: "bar".to_string(),
+            id: "bar".into(),
             payload: StartPayload {
-                query: "subscription Bar {never}".to_string(),
+                query: "subscription Bar {never}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -891,7 +881,7 @@ mod test {
             ServerMessage::Error { id, .. } => {
                 assert_eq!(id, "bar");
             }
-            msg @ _ => panic!("expected error, got: {:?}", msg),
+            msg @ _ => panic!("expected error, got: {msg:?}"),
         }
     }
 
@@ -911,9 +901,9 @@ mod test {
         assert_eq!(ServerMessage::ConnectionAck, conn.next().await.unwrap());
 
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "asd".to_string(),
+                query: "asd".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -929,10 +919,10 @@ mod test {
                         item: ParseError::UnexpectedToken(token),
                         ..
                     }) => assert_eq!(token, "asd"),
-                    p @ _ => panic!("expected graphql parse error, got: {:?}", p),
+                    p @ _ => panic!("expected graphql parse error, got: {p:?}"),
                 }
             }
-            msg @ _ => panic!("expected error, got: {:?}", msg),
+            msg @ _ => panic!("expected error, got: {msg:?}"),
         }
     }
 
@@ -974,9 +964,9 @@ mod test {
 
         // If we send the start message before the init is handled, we should still get results.
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "{context}".to_string(),
+                query: "{context}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -988,7 +978,7 @@ mod test {
 
         assert_eq!(
             ServerMessage::Data {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: DataPayload {
                     data: graphql_value!({"context": 1}),
                     errors: vec![],
@@ -1014,9 +1004,9 @@ mod test {
         assert_eq!(ServerMessage::ConnectionAck, conn.next().await.unwrap());
 
         conn.send(ClientMessage::Start {
-            id: "foo".to_string(),
+            id: "foo".into(),
             payload: StartPayload {
-                query: "subscription Foo {error}".to_string(),
+                query: "subscription Foo {error}".into(),
                 variables: graphql_vars! {},
                 operation_name: None,
             },
@@ -1033,7 +1023,7 @@ mod test {
                 assert_eq!(data, graphql_value!({ "error": null }));
                 assert_eq!(errors.len(), 1);
             }
-            msg @ _ => panic!("expected data, got: {:?}", msg),
+            msg @ _ => panic!("expected data, got: {msg:?}"),
         }
     }
 }
diff --git a/juniper_graphql_ws/src/server_message.rs b/juniper_graphql_ws/src/server_message.rs
index aedc4620..232ef038 100644
--- a/juniper_graphql_ws/src/server_message.rs
+++ b/juniper_graphql_ws/src/server_message.rs
@@ -143,7 +143,7 @@ mod test {
         assert_eq!(
             serde_json::to_string(&ServerMessage::ConnectionError {
                 payload: ConnectionErrorPayload {
-                    message: "foo".to_string(),
+                    message: "foo".into(),
                 },
             })
             .unwrap(),
@@ -157,7 +157,7 @@ mod test {
 
         assert_eq!(
             serde_json::to_string(&ServerMessage::Data {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: DataPayload {
                     data: graphql_value!(null),
                     errors: vec![],
@@ -169,7 +169,7 @@ mod test {
 
         assert_eq!(
             serde_json::to_string(&ServerMessage::Error {
-                id: "foo".to_string(),
+                id: "foo".into(),
                 payload: GraphQLError::UnknownOperationName.into(),
             })
             .unwrap(),
@@ -177,10 +177,7 @@ mod test {
         );
 
         assert_eq!(
-            serde_json::to_string(&ServerMessage::Complete {
-                id: "foo".to_string(),
-            })
-            .unwrap(),
+            serde_json::to_string(&ServerMessage::Complete { id: "foo".into() }).unwrap(),
             r##"{"type":"complete","id":"foo"}"##,
         );
 
diff --git a/juniper_hyper/Cargo.toml b/juniper_hyper/Cargo.toml
index 72ab1f4f..0f2f6bb2 100644
--- a/juniper_hyper/Cargo.toml
+++ b/juniper_hyper/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_hyper"
 version = "0.9.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "`juniper` GraphQL integration with `hyper`."
 license = "BSD-2-Clause"
 authors = ["Damir Vandic <info@dvic.io>"]
diff --git a/juniper_hyper/examples/hyper_server.rs b/juniper_hyper/examples/hyper_server.rs
index 3187451e..afa1d4e0 100644
--- a/juniper_hyper/examples/hyper_server.rs
+++ b/juniper_hyper/examples/hyper_server.rs
@@ -49,9 +49,9 @@ async fn main() {
     });
 
     let server = Server::bind(&addr).serve(new_service);
-    println!("Listening on http://{}", addr);
+    println!("Listening on http://{addr}");
 
     if let Err(e) = server.await {
-        eprintln!("server error: {}", e)
+        eprintln!("server error: {e}")
     }
 }
diff --git a/juniper_hyper/src/lib.rs b/juniper_hyper/src/lib.rs
index ce9204eb..eb8dafe3 100644
--- a/juniper_hyper/src/lib.rs
+++ b/juniper_hyper/src/lib.rs
@@ -84,7 +84,7 @@ fn parse_get_req<S: ScalarValue>(
         .map(|q| gql_request_from_get(q).map(GraphQLBatchRequest::Single))
         .unwrap_or_else(|| {
             Err(GraphQLRequestError::Invalid(
-                "'query' parameter is missing".to_string(),
+                "'query' parameter is missing".into(),
             ))
         })
 }
@@ -144,7 +144,7 @@ pub async fn playground(
 }
 
 fn render_error(err: GraphQLRequestError) -> Response<Body> {
-    let message = format!("{}", err);
+    let message = err.to_string();
     let mut resp = new_response(StatusCode::BAD_REQUEST);
     *resp.body_mut() = Body::from(message);
     resp
@@ -249,15 +249,14 @@ where
     match query {
         Some(query) => Ok(JuniperGraphQLRequest::new(query, operation_name, variables)),
         None => Err(GraphQLRequestError::Invalid(
-            "'query' parameter is missing".to_string(),
+            "'query' parameter is missing".into(),
         )),
     }
 }
 
 fn invalid_err(parameter_name: &str) -> GraphQLRequestError {
     GraphQLRequestError::Invalid(format!(
-        "'{}' parameter is specified multiple times",
-        parameter_name
+        "`{parameter_name}` parameter is specified multiple times",
     ))
 }
 
@@ -330,31 +329,31 @@ mod tests {
 
     impl http_tests::HttpIntegration for TestHyperIntegration {
         fn get(&self, url: &str) -> http_tests::TestResponse {
-            let url = format!("http://127.0.0.1:{}/graphql{}", self.port, url);
-            make_test_response(reqwest::blocking::get(&url).expect(&format!("failed GET {}", url)))
+            let url = format!("http://127.0.0.1:{}/graphql{url}", self.port);
+            make_test_response(reqwest::blocking::get(&url).expect(&format!("failed GET {url}")))
         }
 
         fn post_json(&self, url: &str, body: &str) -> http_tests::TestResponse {
-            let url = format!("http://127.0.0.1:{}/graphql{}", self.port, url);
+            let url = format!("http://127.0.0.1:{}/graphql{url}", self.port);
             let client = reqwest::blocking::Client::new();
             let res = client
                 .post(&url)
                 .header(reqwest::header::CONTENT_TYPE, "application/json")
-                .body(body.to_string())
+                .body(body.to_owned())
                 .send()
-                .expect(&format!("failed POST {}", url));
+                .expect(&format!("failed POST {url}"));
             make_test_response(res)
         }
 
         fn post_graphql(&self, url: &str, body: &str) -> http_tests::TestResponse {
-            let url = format!("http://127.0.0.1:{}/graphql{}", self.port, url);
+            let url = format!("http://127.0.0.1:{}/graphql{url}", self.port);
             let client = reqwest::blocking::Client::new();
             let res = client
                 .post(&url)
                 .header(reqwest::header::CONTENT_TYPE, "application/graphql")
-                .body(body.to_string())
+                .body(body.to_owned())
                 .send()
-                .expect(&format!("failed POST {}", url));
+                .expect(&format!("failed POST {url}"));
             make_test_response(res)
         }
     }
@@ -362,11 +361,9 @@ mod tests {
     fn make_test_response(response: ReqwestResponse) -> http_tests::TestResponse {
         let status_code = response.status().as_u16() as i32;
         let content_type_header = response.headers().get(reqwest::header::CONTENT_TYPE);
-        let content_type = if let Some(ct) = content_type_header {
-            format!("{}", ct.to_str().unwrap())
-        } else {
-            String::default()
-        };
+        let content_type = content_type_header
+            .map(|ct| ct.to_str().unwrap().into())
+            .unwrap_or_default();
         let body = response.text().unwrap();
 
         http_tests::TestResponse {
@@ -439,7 +436,7 @@ mod tests {
         });
 
         if let Err(e) = server.await {
-            eprintln!("server error: {}", e);
+            eprintln!("server error: {e}");
         }
     }
 
diff --git a/juniper_iron/Cargo.toml b/juniper_iron/Cargo.toml
index d4b4b759..82c18f9c 100644
--- a/juniper_iron/Cargo.toml
+++ b/juniper_iron/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_iron"
 version = "0.8.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "`juniper` GraphQL integration with `iron`."
 license = "BSD-2-Clause"
 authors = [
diff --git a/juniper_iron/examples/iron_server.rs b/juniper_iron/examples/iron_server.rs
index d243b221..218af60b 100644
--- a/juniper_iron/examples/iron_server.rs
+++ b/juniper_iron/examples/iron_server.rs
@@ -33,7 +33,7 @@ fn main() {
     chain.link_before(logger_before);
     chain.link_after(logger_after);
 
-    let host = env::var("LISTEN").unwrap_or_else(|_| "0.0.0.0:8080".to_owned());
-    println!("GraphQL server started on {}", host);
+    let host = env::var("LISTEN").unwrap_or_else(|_| "0.0.0.0:8080".into());
+    println!("GraphQL server started on {host}");
     Iron::new(chain).http(host.as_str()).unwrap();
 }
diff --git a/juniper_iron/src/lib.rs b/juniper_iron/src/lib.rs
index 62764227..b8829614 100644
--- a/juniper_iron/src/lib.rs
+++ b/juniper_iron/src/lib.rs
@@ -175,8 +175,8 @@ impl GraphiQLHandler {
     /// relative, so a common value could be `"/graphql"`.
     pub fn new(graphql_url: &str, subscription_url: Option<&str>) -> GraphiQLHandler {
         GraphiQLHandler {
-            graphql_url: graphql_url.to_owned(),
-            subscription_url: subscription_url.map(|s| s.to_owned()),
+            graphql_url: graphql_url.into(),
+            subscription_url: subscription_url.map(Into::into),
         }
     }
 }
@@ -188,8 +188,8 @@ impl PlaygroundHandler {
     /// relative, so a common value could be `"/graphql"`.
     pub fn new(graphql_url: &str, subscription_url: Option<&str>) -> PlaygroundHandler {
         PlaygroundHandler {
-            graphql_url: graphql_url.to_owned(),
-            subscription_url: subscription_url.map(|s| s.to_owned()),
+            graphql_url: graphql_url.into(),
+            subscription_url: subscription_url.map(Into::into),
         }
     }
 }
@@ -283,7 +283,7 @@ impl Error for GraphQLIronError {
 
 impl From<GraphQLIronError> for IronError {
     fn from(err: GraphQLIronError) -> IronError {
-        let message = format!("{}", err);
+        let message = err.to_string();
         IronError::new(err, (status::BadRequest, message))
     }
 }
@@ -313,17 +313,16 @@ mod tests {
     // This is ugly but it works. `iron_test` just dumps the path/url in headers
     // and newer `hyper` doesn't allow unescaped "{" or "}".
     fn fixup_url(url: &str) -> String {
-        let url = Url::parse(&format!("http://localhost:3000{}", url)).expect("url to parse");
+        let url = Url::parse(&format!("http://localhost:3000{url}")).expect("url to parse");
         let path: String = url
             .path()
             .iter()
-            .map(|x| (*x).to_string())
+            .map(|x| x.to_string())
             .collect::<Vec<_>>()
             .join("/");
         format!(
-            "http://localhost:3000{}?{}",
-            path,
-            utf8_percent_encode(url.query().unwrap_or(""), QUERY_ENCODE_SET)
+            "http://localhost:3000{path}?{}",
+            utf8_percent_encode(url.query().unwrap_or(""), QUERY_ENCODE_SET),
         )
     }
 
@@ -374,7 +373,7 @@ mod tests {
         http_tests::TestResponse {
             status_code: 400,
             body: None,
-            content_type: "application/json".to_string(),
+            content_type: "application/json".into(),
         }
     }
 
diff --git a/juniper_rocket/Cargo.toml b/juniper_rocket/Cargo.toml
index e3ff1bec..dc275ee3 100644
--- a/juniper_rocket/Cargo.toml
+++ b/juniper_rocket/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_rocket"
 version = "0.9.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "`juniper` GraphQL integration with `rocket`."
 license = "BSD-2-Clause"
 authors = [
diff --git a/juniper_rocket/src/lib.rs b/juniper_rocket/src/lib.rs
index e6e60bee..fea4e27e 100644
--- a/juniper_rocket/src/lib.rs
+++ b/juniper_rocket/src/lib.rs
@@ -242,9 +242,9 @@ where
 
     fn push_value(ctx: &mut Self::Context, field: ValueField<'f>) {
         match field.name.key().map(|key| key.as_str()) {
-            Some("query") => ctx.query(field.value.to_owned()),
-            Some("operation_name") => ctx.operation_name(field.value.to_owned()),
-            Some("variables") => ctx.variables(field.value.to_owned()),
+            Some("query") => ctx.query(field.value.into()),
+            Some("operation_name") => ctx.operation_name(field.value.into()),
+            Some("variables") => ctx.variables(field.value.into()),
             Some(key) => {
                 if ctx.opts.strict {
                     let error = Error::from(ErrorKind::Unknown).with_name(key);
@@ -318,13 +318,13 @@ where
             let mut reader = data.open(limit);
             let mut body = String::new();
             if let Err(e) = reader.read_to_string(&mut body).await {
-                return Failure((Status::InternalServerError, format!("{:?}", e)));
+                return Failure((Status::InternalServerError, format!("{e:?}")));
             }
 
             Success(GraphQLRequest(if is_json {
                 match serde_json::from_str(&body) {
                     Ok(req) => req,
-                    Err(e) => return Failure((Status::BadRequest, format!("{}", e))),
+                    Err(e) => return Failure((Status::BadRequest, e.to_string())),
                 }
             } else {
                 GraphQLBatchRequest::Single(http::GraphQLRequest::new(body, None, None))
@@ -437,7 +437,7 @@ mod fromform_tests {
         check_error(
             "query=test&variables=NOT_JSON",
             vec![Error::from(ErrorKind::Validation(Cow::Owned(
-                "expected value at line 1 column 1".to_owned(),
+                "expected value at line 1 column 1".into(),
             )))
             .with_name("variables")],
             false,
@@ -451,7 +451,7 @@ mod fromform_tests {
         assert!(result.is_ok());
         let variables = ::serde_json::from_str::<InputValue>(r#"{"foo":"bar"}"#).unwrap();
         let expected = GraphQLRequest(GraphQLBatchRequest::Single(http::GraphQLRequest::new(
-            "test".to_string(),
+            "test".into(),
             None,
             Some(variables),
         )));
@@ -465,7 +465,7 @@ mod fromform_tests {
         ));
         let variables = ::serde_json::from_str::<InputValue>(r#"{"foo":"x y&? z"}"#).unwrap();
         let expected = GraphQLRequest(GraphQLBatchRequest::Single(http::GraphQLRequest::new(
-            "test".to_string(),
+            "test".into(),
             None,
             Some(variables),
         )));
@@ -479,8 +479,8 @@ mod fromform_tests {
         ));
         assert!(result.is_ok());
         let expected = GraphQLRequest(GraphQLBatchRequest::Single(http::GraphQLRequest::new(
-            "%foo bar baz&?".to_string(),
-            Some("test".to_string()),
+            "%foo bar baz&?".into(),
+            Some("test".into()),
             None,
         )));
         assert_eq!(result.unwrap(), expected);
diff --git a/juniper_rocket/tests/custom_response_tests.rs b/juniper_rocket/tests/custom_response_tests.rs
index 050be566..72893703 100644
--- a/juniper_rocket/tests/custom_response_tests.rs
+++ b/juniper_rocket/tests/custom_response_tests.rs
@@ -3,5 +3,5 @@ use rocket::http::Status;
 
 #[test]
 fn test_graphql_response_is_public() {
-    let _ = GraphQLResponse(Status::Unauthorized, "Unauthorized".to_string());
+    let _ = GraphQLResponse(Status::Unauthorized, "Unauthorized".into());
 }
diff --git a/juniper_subscriptions/Cargo.toml b/juniper_subscriptions/Cargo.toml
index ddea6d98..8ccf40e5 100644
--- a/juniper_subscriptions/Cargo.toml
+++ b/juniper_subscriptions/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_subscriptions"
 version = "0.17.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "Juniper `SubscriptionCoordinator` and `SubscriptionConnection` implementations."
 license = "BSD-2-Clause"
 authors = ["nWacky <gosha.evtushenko@gmail.com>"]
diff --git a/juniper_subscriptions/src/lib.rs b/juniper_subscriptions/src/lib.rs
index 6926066d..3d5d77bb 100644
--- a/juniper_subscriptions/src/lib.rs
+++ b/juniper_subscriptions/src/lib.rs
@@ -3,7 +3,6 @@
 #![deny(warnings)]
 
 use std::{
-    iter::FromIterator,
     pin::Pin,
     task::{self, Poll},
 };
diff --git a/juniper_warp/Cargo.toml b/juniper_warp/Cargo.toml
index b49e379d..bb704a20 100644
--- a/juniper_warp/Cargo.toml
+++ b/juniper_warp/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "juniper_warp"
 version = "0.8.0-dev"
-edition = "2018"
+edition = "2021"
+rust-version = "1.62"
 description = "`juniper` GraphQL integration with `warp`."
 license = "BSD-2-Clause"
 authors = ["Tom Houlé <tom@tomhoule.com>"]
diff --git a/juniper_warp/src/lib.rs b/juniper_warp/src/lib.rs
index e7686b8d..b30b007b 100644
--- a/juniper_warp/src/lib.rs
+++ b/juniper_warp/src/lib.rs
@@ -44,7 +44,7 @@ use warp::{body, filters::BoxedFilter, http, hyper::body::Bytes, query, Filter};
 ///         format!(
 ///             "good morning {}, the app state is {:?}",
 ///             context.1,
-///             context.0
+///             context.0,
 ///         )
 ///     }
 /// }
@@ -108,7 +108,7 @@ where
         let schema = post_graphql_schema.clone();
         async move {
             let query = str::from_utf8(body.as_ref())
-                .map_err(|e| anyhow!("Request body query is not a valid UTF-8 string: {}", e))?;
+                .map_err(|e| anyhow!("Request body query is not a valid UTF-8 string: {e}"))?;
             let req = GraphQLRequest::new(query.into(), None, None);
 
             let resp = req.execute(&schema, &context).await;
@@ -192,7 +192,7 @@ where
         async move {
             let res = task::spawn_blocking(move || {
                 let query = str::from_utf8(body.as_ref())
-                    .map_err(|e| anyhow!("Request body is not a valid UTF-8 string: {}", e))?;
+                    .map_err(|e| anyhow!("Request body is not a valid UTF-8 string: {e}"))?;
                 let req = GraphQLRequest::new(query.into(), None, None);
 
                 let resp = req.execute_sync(&schema, &context);
@@ -359,7 +359,7 @@ pub mod subscriptions {
 
     struct Message(warp::ws::Message);
 
-    impl<S: ScalarValue> std::convert::TryFrom<Message> for ClientMessage<S> {
+    impl<S: ScalarValue> TryFrom<Message> for ClientMessage<S> {
         type Error = serde_json::Error;
 
         fn try_from(msg: Message) -> serde_json::Result<Self> {
@@ -381,8 +381,8 @@ pub mod subscriptions {
     impl fmt::Display for Error {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             match self {
-                Self::Warp(e) => write!(f, "warp error: {}", e),
-                Self::Serde(e) => write!(f, "serde error: {}", e),
+                Self::Warp(e) => write!(f, "warp error: {e}"),
+                Self::Serde(e) => write!(f, "serde error: {e}"),
             }
         }
     }
@@ -711,7 +711,7 @@ mod tests_http_harness {
             const QUERY_ENCODE_SET: &AsciiSet =
                 &CONTROLS.add(b' ').add(b'"').add(b'#').add(b'<').add(b'>');
 
-            let url = Url::parse(&format!("http://localhost:3000{}", url)).expect("url to parse");
+            let url = Url::parse(&format!("http://localhost:3000{url}")).expect("url to parse");
 
             let url: String = utf8_percent_encode(url.query().unwrap_or(""), QUERY_ENCODE_SET)
                 .into_iter()
@@ -721,7 +721,7 @@ mod tests_http_harness {
             self.make_request(
                 warp::test::request()
                     .method("GET")
-                    .path(&format!("/?{}", url)),
+                    .path(&format!("/?{url}")),
             )
         }
 
@@ -756,7 +756,7 @@ mod tests_http_harness {
                 .expect("missing content-type header in warp response")
                 .to_str()
                 .expect("invalid content-type string")
-                .to_owned(),
+                .into(),
         }
     }
 
diff --git a/tests/codegen/Cargo.toml b/tests/codegen/Cargo.toml
index f08b1f1a..e8a62a0a 100644
--- a/tests/codegen/Cargo.toml
+++ b/tests/codegen/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "juniper_codegen_tests"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [dependencies]
diff --git a/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.rs b/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.rs
index dfe2d7b5..e2ed37ea 100644
--- a/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.rs
+++ b/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.rs
@@ -7,7 +7,7 @@ pub struct ObjA {
 #[graphql_object(impl = CharacterValue)]
 impl ObjA {
     fn id(&self, is_present: bool) -> &str {
-        is_present.then(|| self.id.as_str()).unwrap_or("missing")
+        is_present.then_some(&*self.id).unwrap_or("missing")
     }
 }
 
diff --git a/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.stderr b/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.stderr
index a1b8ce2f..54af26a8 100644
--- a/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.stderr
+++ b/tests/codegen/fail/interface/struct/attr_additional_non_nullable_argument.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 16 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/struct/attr_additional_non_nullable_argument.rs:16:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/struct/attr_additional_non_nullable_argument.rs:16:5
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 16 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/struct/attr_additional_non_nullable_argument.rs:16:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/attr_missing_field.stderr b/tests/codegen/fail/interface/struct/attr_missing_field.stderr
index 3c3d2ccb..03cc673f 100644
--- a/tests/codegen/fail/interface/struct/attr_missing_field.stderr
+++ b/tests/codegen/fail/interface/struct/attr_missing_field.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/attr_missing_field.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/struct/attr_missing_field.rs:11:5
@@ -337,7 +337,7 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/attr_missing_field.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/struct/attr_missing_field.rs:11:5
@@ -497,7 +497,7 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/attr_missing_field.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/struct/attr_missing_field.rs:11:5
@@ -829,7 +829,7 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/attr_missing_field.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/struct/attr_missing_field.rs:11:5
diff --git a/tests/codegen/fail/interface/struct/attr_missing_for_attr.stderr b/tests/codegen/fail/interface/struct/attr_missing_for_attr.stderr
index b7008d17..cf2b405e 100644
--- a/tests/codegen/fail/interface/struct/attr_missing_for_attr.stderr
+++ b/tests/codegen/fail/interface/struct/attr_missing_for_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 3 | #[derive(GraphQLObject)]
   |          ^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing implementer reference in interface's `for` attribute.', $DIR/fail/interface/struct/attr_missing_for_attr.rs:3:10
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/attr_missing_impl_attr.stderr b/tests/codegen/fail/interface/struct/attr_missing_impl_attr.stderr
index f03491d3..e92ba3d6 100644
--- a/tests/codegen/fail/interface/struct/attr_missing_impl_attr.stderr
+++ b/tests/codegen/fail/interface/struct/attr_missing_impl_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 8 | #[graphql_interface(for = ObjA)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing interface reference in implementer's `impl` attribute.', $DIR/fail/interface/struct/attr_missing_impl_attr.rs:8:1
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/attr_missing_transitive_impl.stderr b/tests/codegen/fail/interface/struct/attr_missing_transitive_impl.stderr
index 389334dc..a77b0085 100644
--- a/tests/codegen/fail/interface/struct/attr_missing_transitive_impl.stderr
+++ b/tests/codegen/fail/interface/struct/attr_missing_transitive_impl.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 8 | #[graphql_interface(impl = Node1Value, for = Node3Value)]
   |                                              ^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Node2` on `Node3`: missing `impl = ` for transitive interface `Node1` on `Node3`.', $DIR/fail/interface/struct/attr_missing_transitive_impl.rs:8:46
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/attr_non_subtype_return.stderr b/tests/codegen/fail/interface/struct/attr_non_subtype_return.stderr
index c5d9903c..67c4553a 100644
--- a/tests/codegen/fail/interface/struct/attr_non_subtype_return.stderr
+++ b/tests/codegen/fail/interface/struct/attr_non_subtype_return.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/struct/attr_non_subtype_return.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/struct/attr_non_subtype_return.rs:11:5
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 11 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/struct/attr_non_subtype_return.rs:11:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.rs b/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.rs
index 5636cc17..3a7d192c 100644
--- a/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.rs
+++ b/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.rs
@@ -7,7 +7,7 @@ pub struct ObjA {
 #[graphql_object(impl = CharacterValue)]
 impl ObjA {
     fn id(&self, is_present: bool) -> &str {
-        is_present.then(|| self.id.as_str()).unwrap_or("missing")
+        is_present.then_some(&*self.id).unwrap_or("missing")
     }
 }
 
diff --git a/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.stderr b/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.stderr
index aa1fd8ee..bb58c8f7 100644
--- a/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.stderr
+++ b/tests/codegen/fail/interface/struct/derive_additional_non_nullable_argument.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 17 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/struct/derive_additional_non_nullable_argument.rs:17:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/struct/derive_additional_non_nullable_argument.rs:17:5
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 17 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/struct/derive_additional_non_nullable_argument.rs:17:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/derive_missing_field.stderr b/tests/codegen/fail/interface/struct/derive_missing_field.stderr
index 086f4ea0..2c164bc0 100644
--- a/tests/codegen/fail/interface/struct/derive_missing_field.stderr
+++ b/tests/codegen/fail/interface/struct/derive_missing_field.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/derive_missing_field.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/struct/derive_missing_field.rs:12:5
@@ -337,7 +337,7 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/derive_missing_field.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/struct/derive_missing_field.rs:12:5
@@ -497,7 +497,7 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/derive_missing_field.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/struct/derive_missing_field.rs:12:5
@@ -829,7 +829,7 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/struct/derive_missing_field.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/struct/derive_missing_field.rs:12:5
diff --git a/tests/codegen/fail/interface/struct/derive_missing_for_attr.stderr b/tests/codegen/fail/interface/struct/derive_missing_for_attr.stderr
index 9f394b97..2364122c 100644
--- a/tests/codegen/fail/interface/struct/derive_missing_for_attr.stderr
+++ b/tests/codegen/fail/interface/struct/derive_missing_for_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 3 | #[derive(GraphQLObject)]
   |          ^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing implementer reference in interface's `for` attribute.', $DIR/fail/interface/struct/derive_missing_for_attr.rs:3:10
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/derive_missing_impl_attr.stderr b/tests/codegen/fail/interface/struct/derive_missing_impl_attr.stderr
index e092494a..98bd18dd 100644
--- a/tests/codegen/fail/interface/struct/derive_missing_impl_attr.stderr
+++ b/tests/codegen/fail/interface/struct/derive_missing_impl_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 8 | #[derive(GraphQLInterface)]
   |          ^^^^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing interface reference in implementer's `impl` attribute.', $DIR/fail/interface/struct/derive_missing_impl_attr.rs:8:10
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/derive_missing_transitive_impl.stderr b/tests/codegen/fail/interface/struct/derive_missing_transitive_impl.stderr
index 278b725f..2b7a8e49 100644
--- a/tests/codegen/fail/interface/struct/derive_missing_transitive_impl.stderr
+++ b/tests/codegen/fail/interface/struct/derive_missing_transitive_impl.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 10 | #[graphql(impl = Node1Value, for = Node3Value)]
    |                                    ^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Node2` on `Node3`: missing `impl = ` for transitive interface `Node1` on `Node3`.', $DIR/fail/interface/struct/derive_missing_transitive_impl.rs:10:36
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/struct/derive_non_subtype_return.stderr b/tests/codegen/fail/interface/struct/derive_non_subtype_return.stderr
index b62b6b0f..7de89146 100644
--- a/tests/codegen/fail/interface/struct/derive_non_subtype_return.stderr
+++ b/tests/codegen/fail/interface/struct/derive_non_subtype_return.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/struct/derive_non_subtype_return.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/struct/derive_non_subtype_return.rs:12:5
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 12 |     id: String,
    |     ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/struct/derive_non_subtype_return.rs:12:5
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/additional_non_nullable_argument.rs b/tests/codegen/fail/interface/trait/additional_non_nullable_argument.rs
index c69f0f66..d8c4060c 100644
--- a/tests/codegen/fail/interface/trait/additional_non_nullable_argument.rs
+++ b/tests/codegen/fail/interface/trait/additional_non_nullable_argument.rs
@@ -7,7 +7,7 @@ pub struct ObjA {
 #[graphql_object(impl = CharacterValue)]
 impl ObjA {
     fn id(&self, is_present: bool) -> &str {
-        is_present.then(|| self.id.as_str()).unwrap_or("missing")
+        is_present.then_some(&*self.id).unwrap_or("missing")
     }
 }
 
diff --git a/tests/codegen/fail/interface/trait/additional_non_nullable_argument.stderr b/tests/codegen/fail/interface/trait/additional_non_nullable_argument.stderr
index 4817ef41..a4030c90 100644
--- a/tests/codegen/fail/interface/trait/additional_non_nullable_argument.stderr
+++ b/tests/codegen/fail/interface/trait/additional_non_nullable_argument.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/trait/additional_non_nullable_argument.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/trait/additional_non_nullable_argument.rs:16:8
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` isn't present on the interface and so has to be nullable.', $DIR/fail/interface/trait/additional_non_nullable_argument.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/missing_field.stderr b/tests/codegen/fail/interface/trait/missing_field.stderr
index e8c94f94..2946f941 100644
--- a/tests/codegen/fail/interface/trait/missing_field.stderr
+++ b/tests/codegen/fail/interface/trait/missing_field.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/trait/missing_field.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/trait/missing_field.rs:11:8
@@ -337,7 +337,7 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/trait/missing_field.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/trait/missing_field.rs:11:8
@@ -497,7 +497,7 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/trait/missing_field.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
   --> fail/interface/trait/missing_field.rs:11:8
@@ -829,7 +829,7 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id` isn't implemented on `ObjA`.', $DIR/fail/interface/trait/missing_field.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: any use of this value will cause an error
   --> fail/interface/trait/missing_field.rs:11:8
diff --git a/tests/codegen/fail/interface/trait/missing_field_argument.stderr b/tests/codegen/fail/interface/trait/missing_field_argument.stderr
index 276222f7..c2f0b857 100644
--- a/tests/codegen/fail/interface/trait/missing_field_argument.stderr
+++ b/tests/codegen/fail/interface/trait/missing_field_argument.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self, is_present: bool) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` was expected, but not found.', $DIR/fail/interface/trait/missing_field_argument.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/trait/missing_field_argument.rs:16:8
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self, is_present: bool) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent` of type `Boolean!` was expected, but not found.', $DIR/fail/interface/trait/missing_field_argument.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/missing_for_attr.stderr b/tests/codegen/fail/interface/trait/missing_for_attr.stderr
index da011ad9..7df8c5b6 100644
--- a/tests/codegen/fail/interface/trait/missing_for_attr.stderr
+++ b/tests/codegen/fail/interface/trait/missing_for_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 3 | #[derive(GraphQLObject)]
   |          ^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing implementer reference in interface's `for` attribute.', $DIR/fail/interface/trait/missing_for_attr.rs:3:10
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/missing_impl_attr.stderr b/tests/codegen/fail/interface/trait/missing_impl_attr.stderr
index a82878d6..64973413 100644
--- a/tests/codegen/fail/interface/trait/missing_impl_attr.stderr
+++ b/tests/codegen/fail/interface/trait/missing_impl_attr.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 8 | #[graphql_interface(for = ObjA)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: missing interface reference in implementer's `impl` attribute.', $DIR/fail/interface/trait/missing_impl_attr.rs:8:1
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/missing_transitive_impl.stderr b/tests/codegen/fail/interface/trait/missing_transitive_impl.stderr
index f120ac36..8655cc68 100644
--- a/tests/codegen/fail/interface/trait/missing_transitive_impl.stderr
+++ b/tests/codegen/fail/interface/trait/missing_transitive_impl.stderr
@@ -4,4 +4,4 @@ error[E0080]: evaluation of constant value failed
 8 | #[graphql_interface(impl = Node1Value, for = Node3Value)]
   |                                              ^^^^^^^^^^ the evaluated program panicked at 'Failed to implement interface `Node2` on `Node3`: missing `impl = ` for transitive interface `Node1` on `Node3`.', $DIR/fail/interface/trait/missing_transitive_impl.rs:8:46
   |
-  = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/non_subtype_return.stderr b/tests/codegen/fail/interface/trait/non_subtype_return.stderr
index 92e123f2..608542e9 100644
--- a/tests/codegen/fail/interface/trait/non_subtype_return.stderr
+++ b/tests/codegen/fail/interface/trait/non_subtype_return.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/trait/non_subtype_return.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/trait/non_subtype_return.rs:11:8
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 11 |     fn id(&self) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: implementor is expected to return a subtype of interface's return object: `[String!]!` is not a subtype of `String!`.', $DIR/fail/interface/trait/non_subtype_return.rs:11:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/interface/trait/wrong_argument_type.stderr b/tests/codegen/fail/interface/trait/wrong_argument_type.stderr
index 3a47b725..3575bacf 100644
--- a/tests/codegen/fail/interface/trait/wrong_argument_type.stderr
+++ b/tests/codegen/fail/interface/trait/wrong_argument_type.stderr
@@ -4,7 +4,7 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self, is_present: bool) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent`: expected type `Boolean!`, found: `Int!`.', $DIR/fail/interface/trait/wrong_argument_type.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0080]: evaluation of constant value failed
   --> fail/interface/trait/wrong_argument_type.rs:16:8
@@ -12,4 +12,4 @@ error[E0080]: evaluation of constant value failed
 16 |     fn id(&self, is_present: bool) -> &str;
    |        ^^ the evaluated program panicked at 'Failed to implement interface `Character` on `ObjA`: Field `id`: Argument `isPresent`: expected type `Boolean!`, found: `Int!`.', $DIR/fail/interface/trait/wrong_argument_type.rs:16:8
    |
-   = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::panic::panic_2021` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/codegen/fail/union/trait_fail_infer_context.stderr b/tests/codegen/fail/union/trait_fail_infer_context.stderr
index ab1d3071..35b54f78 100644
--- a/tests/codegen/fail/union/trait_fail_infer_context.stderr
+++ b/tests/codegen/fail/union/trait_fail_infer_context.stderr
@@ -23,6 +23,6 @@ error[E0308]: mismatched types
 note: associated function defined here
    --> $WORKSPACE/juniper/src/executor/mod.rs
     |
-    |     fn into(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S>;
-    |        ^^^^
+    |     fn into_resolvable(self, ctx: &'a C) -> FieldResult<Option<(&'a T::Context, T)>, S>;
+    |        ^^^^^^^^^^^^^^^
     = note: this error originates in the attribute macro `graphql_union` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/integration/Cargo.toml b/tests/integration/Cargo.toml
index 2b2c3cc7..8645376e 100644
--- a/tests/integration/Cargo.toml
+++ b/tests/integration/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "juniper_integration_tests"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [dependencies]
diff --git a/tests/integration/src/codegen/derive_object_with_raw_idents.rs b/tests/integration/src/codegen/derive_object_with_raw_idents.rs
index c1c5dea7..48d6d159 100644
--- a/tests/integration/src/codegen/derive_object_with_raw_idents.rs
+++ b/tests/integration/src/codegen/derive_object_with_raw_idents.rs
@@ -99,6 +99,6 @@ async fn run_type_info_query(doc: &str) -> Value {
 
     assert_eq!(errs, []);
 
-    println!("Result: {:#?}", result);
+    println!("Result: {result:#?}");
     result
 }
diff --git a/tests/integration/src/codegen/interface_attr_struct.rs b/tests/integration/src/codegen/interface_attr_struct.rs
index 8d0e4f58..5c91b8b7 100644
--- a/tests/integration/src/codegen/interface_attr_struct.rs
+++ b/tests/integration/src/codegen/interface_attr_struct.rs
@@ -117,13 +117,13 @@ mod trivial {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -188,13 +188,12 @@ mod trivial {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -247,17 +246,16 @@ mod trivial {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -347,13 +345,13 @@ mod explicit_alias {
         fn character(&self) -> CharacterEnum {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -418,13 +416,12 @@ mod explicit_alias {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -523,13 +520,13 @@ mod trivial_async {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -591,13 +588,12 @@ mod trivial_async {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -650,17 +646,16 @@ mod trivial_async {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -758,13 +753,13 @@ mod fallible_field {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -829,13 +824,12 @@ mod fallible_field {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -928,13 +922,13 @@ mod generic {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -999,13 +993,12 @@ mod generic {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1054,8 +1047,8 @@ mod description_from_doc_comment {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1121,7 +1114,7 @@ mod deprecation_from_attr {
         }
 
         fn b() -> String {
-            "b".to_owned()
+            "b".into()
         }
     }
 
@@ -1131,8 +1124,8 @@ mod deprecation_from_attr {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1258,7 +1251,7 @@ mod explicit_name_description_and_deprecation {
         }
 
         fn a() -> String {
-            "a".to_owned()
+            "a".into()
         }
 
         fn b() -> &'static str {
@@ -1272,8 +1265,8 @@ mod explicit_name_description_and_deprecation {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1532,13 +1525,13 @@ mod explicit_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1603,13 +1596,12 @@ mod explicit_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1662,13 +1654,13 @@ mod custom_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1733,13 +1725,12 @@ mod custom_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema_with_scalar::<MyScalarValue, _, _>(*root);
+            let schema = schema_with_scalar::<MyScalarValue, _, _>(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1790,13 +1781,13 @@ mod explicit_generic_scalar {
         fn character<S: ScalarValue>(&self) -> CharacterValue<S> {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1861,13 +1852,12 @@ mod explicit_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1918,13 +1908,13 @@ mod bounded_generic_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1989,13 +1979,12 @@ mod bounded_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2031,8 +2020,8 @@ mod ignored_method {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -2143,13 +2132,13 @@ mod field_return_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2214,13 +2203,12 @@ mod field_return_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2297,14 +2285,14 @@ mod field_return_union_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                     key_feature: Knowledge { value: 10 },
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                     strength: 42,
                 }
                 .into(),
@@ -2386,14 +2374,12 @@ mod field_return_union_subtyping {
             }
         }"#;
 
-        for (root, expected_id, expected_val) in &[
+        for (root, expected_id, expected_val) in [
             (QueryRoot::Human, "human-32", 10),
             (QueryRoot::Droid, "droid-99", 42),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
-            let expected_val = *expected_val;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((
@@ -2433,7 +2419,7 @@ mod nullable_argument_subtyping {
         fn id(&self, is_present: Option<bool>) -> &str {
             is_present
                 .unwrap_or_default()
-                .then(|| self.id.as_str())
+                .then_some(&*self.id)
                 .unwrap_or("missing")
         }
 
@@ -2453,13 +2439,13 @@ mod nullable_argument_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2524,13 +2510,12 @@ mod nullable_argument_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "missing"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2566,16 +2551,16 @@ mod simple_subtyping {
     impl QueryRoot {
         fn node() -> NodeValue {
             Endpoint {
-                id: ID::from("1".to_owned()),
-                url: "2".to_owned(),
+                id: ID::new("1"),
+                url: "2".into(),
             }
             .into()
         }
 
         fn resource() -> ResourceValue {
             Endpoint {
-                id: ID::from("3".to_owned()),
-                url: "4".to_owned(),
+                id: ID::new("3"),
+                url: "4".into(),
             }
             .into()
         }
@@ -2586,11 +2571,10 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -2721,14 +2705,13 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         possibleTypes {{
                             kind
                             name
                         }}
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -2765,14 +2748,13 @@ mod simple_subtyping {
         ] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{name}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                name,
             );
 
             assert_eq!(
@@ -2851,8 +2833,8 @@ mod branching_subtyping {
                 Self::Luke => HumanConnection {
                     nodes: vec![Luke {
                         id: ID::new("1"),
-                        home_planet: "earth".to_owned(),
-                        father: "SPOILER".to_owned(),
+                        home_planet: "earth".into(),
+                        father: "SPOILER".into(),
                     }
                     .into()],
                 }
@@ -2860,7 +2842,7 @@ mod branching_subtyping {
                 Self::R2D2 => DroidConnection {
                     nodes: vec![R2D2 {
                         id: ID::new("2"),
-                        primary_function: "roll".to_owned(),
+                        primary_function: "roll".into(),
                         charge: 146.0,
                     }
                     .into()],
@@ -2875,11 +2857,10 @@ mod branching_subtyping {
         for name in ["Node", "Connection", "Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot::Luke);
diff --git a/tests/integration/src/codegen/interface_attr_trait.rs b/tests/integration/src/codegen/interface_attr_trait.rs
index 7892a027..0ee39c8b 100644
--- a/tests/integration/src/codegen/interface_attr_trait.rs
+++ b/tests/integration/src/codegen/interface_attr_trait.rs
@@ -116,13 +116,13 @@ mod trivial {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -187,13 +187,12 @@ mod trivial {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -246,17 +245,16 @@ mod trivial {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -346,13 +344,13 @@ mod explicit_alias {
         fn character(&self) -> CharacterEnum {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -417,13 +415,12 @@ mod explicit_alias {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -522,13 +519,13 @@ mod trivial_async {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -593,13 +590,12 @@ mod trivial_async {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -652,17 +648,16 @@ mod trivial_async {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -760,13 +755,13 @@ mod fallible_field {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -831,13 +826,12 @@ mod fallible_field {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -927,13 +921,13 @@ mod generic {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -995,13 +989,12 @@ mod generic {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1074,8 +1067,8 @@ mod argument {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1085,7 +1078,7 @@ mod argument {
     async fn resolves_id_field() {
         let schema = schema(QueryRoot);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             (
                 "{ character { idWide(isNumber: true), idWide2(isNumber: true) } }",
                 "human-32",
@@ -1095,10 +1088,8 @@ mod argument {
                 "none",
             ),
         ] {
-            let expected: &str = *expected;
-
             assert_eq!(
-                execute(*input, None, &schema, &graphql_vars! {}, &()).await,
+                execute(input, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((
                     graphql_value!({"character": {
                         "idWide": expected,
@@ -1211,7 +1202,7 @@ mod default_argument {
         fn id(
             &self,
             #[graphql(default)] first: String,
-            #[graphql(default = "second".to_string())] second: String,
+            #[graphql(default = "second")] second: String,
             #[graphql(default = "t")] third: String,
         ) -> String;
 
@@ -1227,7 +1218,7 @@ mod default_argument {
         }
 
         async fn id(&self, first: String, second: String, third: String) -> String {
-            format!("{}|{}&{}", first, second, third)
+            format!("{first}|{second}&{third}")
         }
     }
 
@@ -1244,7 +1235,7 @@ mod default_argument {
     async fn resolves_id_field() {
         let schema = schema(QueryRoot);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             ("{ character { id } }", "|second&t"),
             (r#"{ character { id(first: "first") } }"#, "first|second&t"),
             (r#"{ character { id(second: "") } }"#, "|&t"),
@@ -1257,10 +1248,8 @@ mod default_argument {
                 "first|&",
             ),
         ] {
-            let expected: &str = *expected;
-
             assert_eq!(
-                execute(*input, None, &schema, &graphql_vars! {}, &()).await,
+                execute(input, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected}}), vec![])),
             );
         }
@@ -1270,14 +1259,12 @@ mod default_argument {
     async fn resolves_info_field() {
         let schema = schema(QueryRoot);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             ("{ character { info } }", 1),
             ("{ character { info(coord: {x: 2}) } }", 2),
         ] {
-            let expected: i32 = *expected;
-
             assert_eq!(
-                execute(*input, None, &schema, &graphql_vars! {}, &()).await,
+                execute(input, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"info": expected}}), vec![])),
             );
         }
@@ -1358,8 +1345,8 @@ mod description_from_doc_comment {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1425,7 +1412,7 @@ mod deprecation_from_attr {
         }
 
         fn b() -> String {
-            "b".to_owned()
+            "b".into()
         }
     }
 
@@ -1435,8 +1422,8 @@ mod deprecation_from_attr {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1562,7 +1549,7 @@ mod explicit_name_description_and_deprecation {
         }
 
         fn a() -> String {
-            "a".to_owned()
+            "a".into()
         }
 
         fn b() -> &'static str {
@@ -1576,8 +1563,8 @@ mod explicit_name_description_and_deprecation {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1854,13 +1841,13 @@ mod explicit_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1925,13 +1912,12 @@ mod explicit_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1984,13 +1970,13 @@ mod custom_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2055,13 +2041,12 @@ mod custom_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema_with_scalar::<MyScalarValue, _, _>(*root);
+            let schema = schema_with_scalar::<MyScalarValue, _, _>(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2112,13 +2097,13 @@ mod explicit_generic_scalar {
         fn character<S: ScalarValue>(&self) -> CharacterValue<S> {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2183,13 +2168,12 @@ mod explicit_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2240,13 +2224,13 @@ mod bounded_generic_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2311,13 +2295,12 @@ mod bounded_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2401,13 +2384,13 @@ mod explicit_custom_context {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2474,15 +2457,12 @@ mod explicit_custom_context {
             }
         }"#;
 
-        for (root, expected_id, expected_info, expexted_more) in &[
+        for (root, expected_id, expected_info, expexted_more) in [
             (QueryRoot::Human, "human-32", "earth", "human"),
             (QueryRoot::Droid, "droid-99", "run", "droid"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
-            let expected_info: &str = *expected_info;
-            let expexted_more: &str = *expexted_more;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &CustomContext).await,
                 Ok((
@@ -2561,11 +2541,11 @@ mod inferred_custom_context_from_field {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    home_planet: "earth".to_string(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    primary_function: "run".to_string(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2633,15 +2613,13 @@ mod inferred_custom_context_from_field {
             }
         }"#;
 
-        for (root, expected_id, expected_info) in &[
+        for (root, expected_id, expected_info) in [
             (QueryRoot::Human, "human-ctx", "earth"),
             (QueryRoot::Droid, "droid-ctx", "run"),
         ] {
-            let schema = schema(*root);
-            let ctx = CustomContext(expected_id.to_string());
+            let schema = schema(root);
+            let ctx = CustomContext(expected_id.into());
 
-            let expected_id: &str = *expected_id;
-            let expected_info: &str = *expected_info;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &ctx).await,
                 Ok((
@@ -2725,11 +2703,11 @@ mod executor {
         fn character(&self) -> CharacterValue<DefaultScalarValue> {
             match self {
                 Self::Human => Human {
-                    home_planet: "earth".to_string(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    primary_function: "run".to_string(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2795,10 +2773,9 @@ mod executor {
             }
         }"#;
 
-        for (root, expected_info) in &[(QueryRoot::Human, "earth"), (QueryRoot::Droid, "run")] {
-            let schema = schema(*root);
+        for (root, expected_info) in [(QueryRoot::Human, "earth"), (QueryRoot::Droid, "run")] {
+            let schema = schema(root);
 
-            let expected_info: &str = *expected_info;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((
@@ -2869,8 +2846,8 @@ mod ignored_method {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -2981,13 +2958,13 @@ mod field_return_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -3052,13 +3029,12 @@ mod field_return_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -3136,14 +3112,14 @@ mod field_return_union_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                     key_feature: Knowledge { value: 10 },
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                     strength: 42,
                 }
                 .into(),
@@ -3225,14 +3201,12 @@ mod field_return_union_subtyping {
             }
         }"#;
 
-        for (root, expected_id, expected_val) in &[
+        for (root, expected_id, expected_val) in [
             (QueryRoot::Human, "human-32", 10),
             (QueryRoot::Droid, "droid-99", 42),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
-            let expected_val = *expected_val;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((
@@ -3272,7 +3246,7 @@ mod nullable_argument_subtyping {
         fn id(&self, is_present: Option<bool>) -> &str {
             is_present
                 .unwrap_or_default()
-                .then(|| self.id.as_str())
+                .then_some(&*self.id)
                 .unwrap_or("missing")
         }
 
@@ -3292,13 +3266,13 @@ mod nullable_argument_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -3363,13 +3337,12 @@ mod nullable_argument_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "missing"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -3405,16 +3378,16 @@ mod simple_subtyping {
     impl QueryRoot {
         fn node() -> NodeValue {
             Endpoint {
-                id: ID::from("1".to_owned()),
-                url: "2".to_owned(),
+                id: ID::new("1"),
+                url: "2".into(),
             }
             .into()
         }
 
         fn resource() -> ResourceValue {
             Endpoint {
-                id: ID::from("3".to_owned()),
-                url: "4".to_owned(),
+                id: ID::new("3"),
+                url: "4".into(),
             }
             .into()
         }
@@ -3425,11 +3398,10 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -3560,14 +3532,13 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         possibleTypes {{
                             kind
                             name
                         }}
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -3604,14 +3575,13 @@ mod simple_subtyping {
         ] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{name}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                name,
             );
 
             assert_eq!(
@@ -3690,8 +3660,8 @@ mod branching_subtyping {
                 Self::Luke => HumanConnection {
                     nodes: vec![Luke {
                         id: ID::new("1"),
-                        home_planet: "earth".to_owned(),
-                        father: "SPOILER".to_owned(),
+                        home_planet: "earth".into(),
+                        father: "SPOILER".into(),
                     }
                     .into()],
                 }
@@ -3699,7 +3669,7 @@ mod branching_subtyping {
                 Self::R2D2 => DroidConnection {
                     nodes: vec![R2D2 {
                         id: ID::new("2"),
-                        primary_function: "roll".to_owned(),
+                        primary_function: "roll".into(),
                         charge: 146.0,
                     }
                     .into()],
@@ -3714,11 +3684,10 @@ mod branching_subtyping {
         for name in ["Node", "Connection", "Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot::Luke);
diff --git a/tests/integration/src/codegen/interface_derive.rs b/tests/integration/src/codegen/interface_derive.rs
index bbc6a79a..f5a24bf3 100644
--- a/tests/integration/src/codegen/interface_derive.rs
+++ b/tests/integration/src/codegen/interface_derive.rs
@@ -118,13 +118,13 @@ mod trivial {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -189,13 +189,12 @@ mod trivial {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -248,17 +247,16 @@ mod trivial {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -349,13 +347,13 @@ mod explicit_alias {
         fn character(&self) -> CharacterEnum {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -420,13 +418,12 @@ mod explicit_alias {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -526,13 +523,13 @@ mod trivial_async {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -597,13 +594,12 @@ mod trivial_async {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -656,17 +652,16 @@ mod trivial_async {
     async fn registers_itself_in_implementers() {
         let schema = schema(QueryRoot::Human);
 
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{object}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                object,
             );
 
             assert_eq!(
@@ -765,13 +760,13 @@ mod fallible_field {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -836,13 +831,12 @@ mod fallible_field {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -936,13 +930,13 @@ mod generic {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1007,13 +1001,12 @@ mod generic {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1063,8 +1056,8 @@ mod description_from_doc_comment {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1131,7 +1124,7 @@ mod deprecation_from_attr {
         }
 
         fn b() -> String {
-            "b".to_owned()
+            "b".into()
         }
     }
 
@@ -1141,8 +1134,8 @@ mod deprecation_from_attr {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1269,7 +1262,7 @@ mod explicit_name_description_and_deprecation {
         }
 
         fn a() -> String {
-            "a".to_owned()
+            "a".into()
         }
 
         fn b() -> &'static str {
@@ -1283,8 +1276,8 @@ mod explicit_name_description_and_deprecation {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -1545,13 +1538,13 @@ mod explicit_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1616,13 +1609,12 @@ mod explicit_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1676,13 +1668,13 @@ mod custom_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1747,13 +1739,12 @@ mod custom_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema_with_scalar::<MyScalarValue, _, _>(*root);
+            let schema = schema_with_scalar::<MyScalarValue, _, _>(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1805,13 +1796,13 @@ mod explicit_generic_scalar {
         fn character<S: ScalarValue>(&self) -> CharacterValue<S> {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -1876,13 +1867,12 @@ mod explicit_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -1934,13 +1924,13 @@ mod bounded_generic_scalar {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2005,13 +1995,12 @@ mod bounded_generic_scalar {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2048,8 +2037,8 @@ mod ignored_method {
     impl QueryRoot {
         fn character(&self) -> CharacterValue {
             Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }
             .into()
         }
@@ -2161,13 +2150,13 @@ mod field_return_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2232,13 +2221,12 @@ mod field_return_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "droid-99"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2316,14 +2304,14 @@ mod field_return_union_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                     key_feature: Knowledge { value: 10 },
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                     strength: 42,
                 }
                 .into(),
@@ -2405,14 +2393,12 @@ mod field_return_union_subtyping {
             }
         }"#;
 
-        for (root, expected_id, expected_val) in &[
+        for (root, expected_id, expected_val) in [
             (QueryRoot::Human, "human-32", 10),
             (QueryRoot::Droid, "droid-99", 42),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
-            let expected_val = *expected_val;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((
@@ -2453,7 +2439,7 @@ mod nullable_argument_subtyping {
         fn id(&self, is_present: Option<bool>) -> &str {
             is_present
                 .unwrap_or_default()
-                .then(|| self.id.as_str())
+                .then_some(&*self.id)
                 .unwrap_or("missing")
         }
 
@@ -2473,13 +2459,13 @@ mod nullable_argument_subtyping {
         fn character(&self) -> CharacterValue {
             match self {
                 Self::Human => Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }
                 .into(),
                 Self::Droid => Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }
                 .into(),
             }
@@ -2544,13 +2530,12 @@ mod nullable_argument_subtyping {
             }
         }"#;
 
-        for (root, expected_id) in &[
+        for (root, expected_id) in [
             (QueryRoot::Human, "human-32"),
             (QueryRoot::Droid, "missing"),
         ] {
-            let schema = schema(*root);
+            let schema = schema(root);
 
-            let expected_id: &str = *expected_id;
             assert_eq!(
                 execute(DOC, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"character": {"id": expected_id}}), vec![])),
@@ -2588,16 +2573,16 @@ mod simple_subtyping {
     impl QueryRoot {
         fn node() -> NodeValue {
             Endpoint {
-                id: ID::from("1".to_owned()),
-                url: "2".to_owned(),
+                id: ID::new("1"),
+                url: "2".into(),
             }
             .into()
         }
 
         fn resource() -> ResourceValue {
             Endpoint {
-                id: ID::from("3".to_owned()),
-                url: "4".to_owned(),
+                id: ID::new("3"),
+                url: "4".into(),
             }
             .into()
         }
@@ -2608,11 +2593,10 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -2743,14 +2727,13 @@ mod simple_subtyping {
         for name in ["Node", "Resource"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         possibleTypes {{
                             kind
                             name
                         }}
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -2787,14 +2770,13 @@ mod simple_subtyping {
         ] {
             let doc = format!(
                 r#"{{
-                   __type(name: "{}") {{
+                   __type(name: "{name}") {{
                        interfaces {{
                            kind
                            name
                        }}
                    }}
                 }}"#,
-                name,
             );
 
             assert_eq!(
@@ -2877,8 +2859,8 @@ mod branching_subtyping {
                 Self::Luke => HumanConnection {
                     nodes: vec![Luke {
                         id: ID::new("1"),
-                        home_planet: "earth".to_owned(),
-                        father: "SPOILER".to_owned(),
+                        home_planet: "earth".into(),
+                        father: "SPOILER".into(),
                     }
                     .into()],
                 }
@@ -2886,7 +2868,7 @@ mod branching_subtyping {
                 Self::R2D2 => DroidConnection {
                     nodes: vec![R2D2 {
                         id: ID::new("2"),
-                        primary_function: "roll".to_owned(),
+                        primary_function: "roll".into(),
                         charge: 146.0,
                     }
                     .into()],
@@ -2901,11 +2883,10 @@ mod branching_subtyping {
         for name in ["Node", "Connection", "Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot::Luke);
diff --git a/tests/integration/src/codegen/object_attr.rs b/tests/integration/src/codegen/object_attr.rs
index 5a10710c..6c3cdd9d 100644
--- a/tests/integration/src/codegen/object_attr.rs
+++ b/tests/integration/src/codegen/object_attr.rs
@@ -376,7 +376,7 @@ mod fallible_method {
     impl QueryRoot {
         fn human() -> Human {
             Human {
-                id: "human-32".to_string(),
+                id: "human-32".into(),
             }
         }
     }
@@ -885,22 +885,20 @@ mod nested_generic_lifetime_async {
 
     #[tokio::test]
     async fn uses_type_name_without_type_params() {
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{object}") {{
                         name
                     }}
                 }}"#,
-                object,
             );
 
             let schema = schema(QueryRoot("mars".into()));
 
-            let expected_name: &str = *object;
             assert_eq!(
                 execute(&doc, None, &schema, &graphql_vars! {}, &()).await,
-                Ok((graphql_value!({"__type": {"name": expected_name}}), vec![])),
+                Ok((graphql_value!({"__type": {"name": object}}), vec![])),
             );
         }
     }
@@ -918,7 +916,7 @@ mod argument {
         }
 
         async fn home_planet(&self, r#raw_arg: String, r#async: Option<i32>) -> String {
-            format!("{},{:?}", r#raw_arg, r#async)
+            format!("{raw_arg},{async:?}")
         }
     }
 
@@ -1048,7 +1046,7 @@ mod default_argument {
             #[graphql(default = "second".to_string())] arg2: Option<String>,
             #[graphql(default = true)] r#arg3: bool,
         ) -> String {
-            format!("{}|{:?}&{}", arg1, arg2, r#arg3)
+            format!("{arg1}|{arg2:?}&{arg3}")
         }
 
         fn info(#[graphql(default = Point { x: 1 })] coord: Point) -> i32 {
@@ -1069,7 +1067,7 @@ mod default_argument {
     async fn resolves_id_field() {
         let schema = schema(QueryRoot);
 
-        for (input, expected, vars) in &[
+        for (input, expected, vars) in [
             (
                 "{ human { id } }",
                 r#"0|Some("second")&true"#,
@@ -1131,10 +1129,8 @@ mod default_argument {
                 graphql_vars! {},
             ),
         ] {
-            let expected: &str = *expected;
-
             assert_eq!(
-                execute(*input, None, &schema, &vars, &(),).await,
+                execute(input, None, &schema, &vars, &(),).await,
                 Ok((graphql_value!({"human": {"id": expected}}), vec![])),
             );
         }
@@ -1144,14 +1140,12 @@ mod default_argument {
     async fn resolves_info_field() {
         let schema = schema(QueryRoot);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             ("{ human { info } }", 1),
             ("{ human { info(coord: { x: 2 }) } }", 2),
         ] {
-            let expected: i32 = *expected;
-
             assert_eq!(
-                execute(*input, None, &schema, &graphql_vars! {}, &()).await,
+                execute(input, None, &schema, &graphql_vars! {}, &()).await,
                 Ok((graphql_value!({"human": {"info": expected}}), vec![])),
             );
         }
diff --git a/tests/integration/src/codegen/object_derive.rs b/tests/integration/src/codegen/object_derive.rs
index 126c315a..9b0b86d8 100644
--- a/tests/integration/src/codegen/object_derive.rs
+++ b/tests/integration/src/codegen/object_derive.rs
@@ -406,22 +406,20 @@ mod nested_generic_lifetime_async {
 
     #[tokio::test]
     async fn uses_type_name_without_type_params() {
-        for object in &["Human", "Droid"] {
+        for object in ["Human", "Droid"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{object}") {{
                         name
                     }}
                 }}"#,
-                object,
             );
 
             let schema = schema(QueryRoot("mars".into()));
 
-            let expected_name: &str = *object;
             assert_eq!(
                 execute(&doc, None, &schema, &graphql_vars! {}, &()).await,
-                Ok((graphql_value!({"__type": {"name": expected_name}}), vec![])),
+                Ok((graphql_value!({"__type": {"name": object}}), vec![])),
             );
         }
     }
diff --git a/tests/integration/src/codegen/scalar_attr_derive_input.rs b/tests/integration/src/codegen/scalar_attr_derive_input.rs
index e2b30a30..dd10bd30 100644
--- a/tests/integration/src/codegen/scalar_attr_derive_input.rs
+++ b/tests/integration/src/codegen/scalar_attr_derive_input.rs
@@ -29,7 +29,7 @@ mod trivial {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(t: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -237,7 +237,7 @@ mod all_custom_resolvers {
     fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
         v.as_int_value()
             .map(Counter)
-            .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
     }
 
     fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -312,7 +312,7 @@ mod explicit_name {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -388,7 +388,7 @@ mod delegated_parse_token {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -458,7 +458,7 @@ mod multiple_delegated_parse_token {
     impl StringOrInt {
         fn to_output<S: ScalarValue>(&self) -> Value<S> {
             match self {
-                Self::String(str) => Value::scalar(str.to_owned()),
+                Self::String(s) => Value::scalar(s.to_owned()),
                 Self::Int(i) => Value::scalar(*i),
             }
         }
@@ -467,7 +467,7 @@ mod multiple_delegated_parse_token {
             v.as_string_value()
                 .map(|s| Self::String(s.to_owned()))
                 .or_else(|| v.as_int_value().map(Self::Int))
-                .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
         }
     }
 
@@ -533,11 +533,11 @@ mod where_attribute {
         Tz::Offset: fmt::Display,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 DateTime::parse_from_rfc3339(s)
                     .map(|dt| CustomDateTime(dt.with_timezone(&Tz::from(Utc))))
-                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
             })
     }
 
@@ -599,7 +599,7 @@ mod with_self {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -691,11 +691,11 @@ mod with_module {
             Tz::Offset: fmt::Display,
         {
             v.as_string_value()
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
                 .and_then(|s| {
                     DateTime::parse_from_rfc3339(s)
                         .map(|dt| CustomDateTime(dt.with_timezone(&Tz::from(Utc))))
-                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
                 })
         }
     }
@@ -759,7 +759,7 @@ mod description_from_doc_comment {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -835,7 +835,7 @@ mod description_from_attribute {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -911,7 +911,7 @@ mod custom_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -987,7 +987,7 @@ mod generic_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -1062,7 +1062,7 @@ mod bounded_generic_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
diff --git a/tests/integration/src/codegen/scalar_attr_type_alias.rs b/tests/integration/src/codegen/scalar_attr_type_alias.rs
index 66e25442..900f0612 100644
--- a/tests/integration/src/codegen/scalar_attr_type_alias.rs
+++ b/tests/integration/src/codegen/scalar_attr_type_alias.rs
@@ -34,7 +34,7 @@ mod all_custom_resolvers {
     fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
         v.as_int_value()
             .map(CustomCounter)
-            .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
     }
 
     fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -115,7 +115,7 @@ mod explicit_name {
     fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<CounterScalar, String> {
         v.as_int_value()
             .map(CustomCounter)
-            .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
     }
 
     fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -152,11 +152,10 @@ mod explicit_name {
         for name in ["CustomCounter", "CustomScalar"] {
             let doc = format!(
                 r#"{{
-                    __type(name: "{}") {{
+                    __type(name: "{name}") {{
                         kind
                     }}
                 }}"#,
-                name,
             );
 
             let schema = schema(QueryRoot);
@@ -216,7 +215,7 @@ mod delegated_parse_token {
     fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
         v.as_int_value()
             .map(CustomCounter)
-            .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
     }
 
     struct QueryRoot;
@@ -290,7 +289,7 @@ mod multiple_delegated_parse_token {
 
     fn to_output<S: ScalarValue>(v: &StringOrInt) -> Value<S> {
         match v {
-            StringOrInt::String(str) => Value::scalar(str.to_owned()),
+            StringOrInt::String(s) => Value::scalar(s.to_owned()),
             StringOrInt::Int(i) => Value::scalar(*i),
         }
     }
@@ -299,7 +298,7 @@ mod multiple_delegated_parse_token {
         v.as_string_value()
             .map(|s| StringOrInt::String(s.to_owned()))
             .or_else(|| v.as_int_value().map(|i| StringOrInt::Int(i)))
-            .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
     }
 
     struct QueryRoot;
@@ -366,11 +365,11 @@ mod where_attribute {
         Tz::Offset: fmt::Display,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 DateTime::parse_from_rfc3339(s)
                     .map(|dt| CustomDateTimeScalar(dt.with_timezone(&Tz::from(Utc))))
-                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
             })
     }
 
@@ -434,7 +433,7 @@ mod with_self {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -528,11 +527,11 @@ mod with_module {
             Tz::Offset: fmt::Display,
         {
             v.as_string_value()
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
                 .and_then(|s| {
                     DateTime::parse_from_rfc3339(s)
                         .map(|dt| CustomDateTimeScalar(dt.with_timezone(&Tz::from(Utc))))
-                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
                 })
         }
     }
@@ -600,7 +599,7 @@ mod description_from_doc_comment {
         pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
             v.as_int_value()
                 .map(CustomCounter)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -684,7 +683,7 @@ mod description_from_attribute {
         pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
             v.as_int_value()
                 .map(CustomCounter)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -768,7 +767,7 @@ mod custom_scalar {
         pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
             v.as_int_value()
                 .map(CustomCounter)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -852,7 +851,7 @@ mod generic_scalar {
         pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
             v.as_int_value()
                 .map(CustomCounter)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -936,7 +935,7 @@ mod bounded_generic_scalar {
         pub(super) fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
             v.as_int_value()
                 .map(CustomCounter)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
diff --git a/tests/integration/src/codegen/scalar_derive.rs b/tests/integration/src/codegen/scalar_derive.rs
index 45bd2a81..bdf9791d 100644
--- a/tests/integration/src/codegen/scalar_derive.rs
+++ b/tests/integration/src/codegen/scalar_derive.rs
@@ -27,7 +27,7 @@ mod trivial {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(t: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -235,7 +235,7 @@ mod all_custom_resolvers {
     fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Counter, String> {
         v.as_int_value()
             .map(Counter)
-            .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+            .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
     }
 
     fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -311,7 +311,7 @@ mod explicit_name {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -388,7 +388,7 @@ mod delegated_parse_token {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -459,7 +459,7 @@ mod multiple_delegated_parse_token {
     impl StringOrInt {
         fn to_output<S: ScalarValue>(&self) -> Value<S> {
             match self {
-                Self::String(str) => Value::scalar(str.to_owned()),
+                Self::String(s) => Value::scalar(s.to_owned()),
                 Self::Int(i) => Value::scalar(*i),
             }
         }
@@ -468,7 +468,7 @@ mod multiple_delegated_parse_token {
             v.as_string_value()
                 .map(|s| Self::String(s.to_owned()))
                 .or_else(|| v.as_int_value().map(Self::Int))
-                .ok_or_else(|| format!("Expected `String` or `Int`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String` or `Int`, found: {v}"))
         }
     }
 
@@ -535,11 +535,11 @@ mod where_attribute {
         Tz::Offset: fmt::Display,
     {
         v.as_string_value()
-            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .ok_or_else(|| format!("Expected `String`, found: {v}"))
             .and_then(|s| {
                 DateTime::parse_from_rfc3339(s)
                     .map(|dt| CustomDateTime(dt.with_timezone(&Tz::from(Utc))))
-                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                    .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
             })
     }
 
@@ -602,7 +602,7 @@ mod with_self {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
 
         fn parse_token<S: ScalarValue>(value: ScalarToken<'_>) -> ParseScalarResult<S> {
@@ -695,11 +695,11 @@ mod with_module {
             Tz::Offset: fmt::Display,
         {
             v.as_string_value()
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
                 .and_then(|s| {
                     DateTime::parse_from_rfc3339(s)
                         .map(|dt| CustomDateTime(dt.with_timezone(&Tz::from(Utc))))
-                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {}", e))
+                        .map_err(|e| format!("Failed to parse `CustomDateTime`: {e}"))
                 })
         }
     }
@@ -764,7 +764,7 @@ mod description_from_doc_comment {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -841,7 +841,7 @@ mod description_from_attribute {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -918,7 +918,7 @@ mod custom_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -995,7 +995,7 @@ mod generic_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `Counter`, found: {}", v))
+                .ok_or_else(|| format!("Expected `Counter`, found: {v}"))
         }
     }
 
@@ -1071,7 +1071,7 @@ mod bounded_generic_scalar {
         fn from_input<S: ScalarValue>(v: &InputValue<S>) -> Result<Self, String> {
             v.as_int_value()
                 .map(Self)
-                .ok_or_else(|| format!("Expected `String`, found: {}", v))
+                .ok_or_else(|| format!("Expected `String`, found: {v}"))
         }
     }
 
diff --git a/tests/integration/src/codegen/subscription_attr.rs b/tests/integration/src/codegen/subscription_attr.rs
index 47535fab..94214235 100644
--- a/tests/integration/src/codegen/subscription_attr.rs
+++ b/tests/integration/src/codegen/subscription_attr.rs
@@ -53,12 +53,12 @@ mod trivial {
     #[graphql_subscription]
     impl Human {
         async fn id() -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready("human-32".to_owned())))
+            Box::pin(stream::once(future::ready("human-32".into())))
         }
 
         // TODO: Make work for `Stream<'_, String>`.
         async fn home_planet(&self) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready("earth".to_owned())))
+            Box::pin(stream::once(future::ready("earth".into())))
         }
     }
 
@@ -227,7 +227,7 @@ mod ignored_method {
     #[graphql_subscription]
     impl Human {
         async fn id() -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready("human-32".to_owned())))
+            Box::pin(stream::once(future::ready("human-32".into())))
         }
 
         #[allow(dead_code)]
@@ -291,7 +291,7 @@ mod fallible_method {
     #[graphql_subscription]
     impl Human {
         async fn id(&self) -> Result<Stream<'static, String>, CustomError> {
-            Ok(Box::pin(stream::once(future::ready("human-32".to_owned()))))
+            Ok(Box::pin(stream::once(future::ready("human-32".into()))))
         }
 
         async fn home_planet<__S>() -> FieldResult<Stream<'static, &'static str>, __S> {
@@ -387,10 +387,7 @@ mod argument {
             r#raw_arg: String,
             r#async: Option<i32>,
         ) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(format!(
-                "{},{:?}",
-                r#raw_arg, r#async
-            ))))
+            Box::pin(stream::once(future::ready(format!("{raw_arg},{async:?}"))))
         }
     }
 
@@ -524,10 +521,7 @@ mod default_argument {
             #[graphql(default = "second".to_string())] arg2: String,
             #[graphql(default = true)] r#arg3: bool,
         ) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(format!(
-                "{}|{}&{}",
-                arg1, arg2, r#arg3
-            ))))
+            Box::pin(stream::once(future::ready(format!("{arg1}|{arg2}&{arg3}"))))
         }
 
         async fn info(#[graphql(default = Point { x: 1 })] coord: Point) -> Stream<'static, i32> {
@@ -539,7 +533,7 @@ mod default_argument {
     async fn resolves_id_field() {
         let schema = schema(Query, Human);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             ("subscription { id }", "0|second&true"),
             ("subscription { id(arg1: 1) }", "1|second&true"),
             (r#"subscription { id(arg2: "") }"#, "0|&true"),
@@ -549,10 +543,8 @@ mod default_argument {
                 "1|&false",
             ),
         ] {
-            let expected: &str = *expected;
-
             assert_eq!(
-                resolve_into_stream(*input, None, &schema, &graphql_vars! {}, &())
+                resolve_into_stream(input, None, &schema, &graphql_vars! {}, &())
                     .then(|s| extract_next(s))
                     .await,
                 Ok((graphql_value!({ "id": expected }), vec![])),
@@ -564,14 +556,12 @@ mod default_argument {
     async fn resolves_info_field() {
         let schema = schema(Query, Human);
 
-        for (input, expected) in &[
+        for (input, expected) in [
             ("subscription { info }", 1),
             ("subscription { info(coord: { x: 2 }) }", 2),
         ] {
-            let expected: i32 = *expected;
-
             assert_eq!(
-                resolve_into_stream(*input, None, &schema, &graphql_vars! {}, &())
+                resolve_into_stream(input, None, &schema, &graphql_vars! {}, &())
                     .then(|s| extract_next(s))
                     .await,
                 Ok((graphql_value!({ "info": expected }), vec![])),
@@ -648,7 +638,7 @@ mod generic {
     #[graphql_subscription(name = "HumanString")]
     impl<B: ?Sized + Sync> Human<String, B> {
         async fn id(&self) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(self.id.to_owned())))
+            Box::pin(stream::once(future::ready(self.id.clone())))
         }
     }
 
@@ -735,7 +725,7 @@ mod generic_lifetime {
 
         // TODO: Make it work with `Stream<'_, &str>`.
         async fn planet(&self) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(self.home_planet.to_owned())))
+            Box::pin(stream::once(future::ready(self.home_planet.into())))
         }
     }
 
@@ -743,12 +733,12 @@ mod generic_lifetime {
     impl<'id, 'p> Human<'p, &'id str> {
         // TODO: Make it work with `Stream<'_, &str>`.
         async fn id(&self) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(self.id.to_owned())))
+            Box::pin(stream::once(future::ready(self.id.into())))
         }
 
         // TODO: Make it work with `Stream<'_, &str>`.
         async fn planet(&self) -> Stream<'static, String> {
-            Box::pin(stream::once(future::ready(self.home_planet.to_owned())))
+            Box::pin(stream::once(future::ready(self.home_planet.into())))
         }
     }
 
@@ -1702,7 +1692,7 @@ mod executor {
             S: ScalarValue,
         {
             Box::pin(stream::once(future::ready(
-                executor.look_ahead().field_name().to_owned(),
+                executor.look_ahead().field_name().into(),
             )))
         }
 
diff --git a/tests/integration/src/codegen/union_attr.rs b/tests/integration/src/codegen/union_attr.rs
index 9f032c4c..51e9da89 100644
--- a/tests/integration/src/codegen/union_attr.rs
+++ b/tests/integration/src/codegen/union_attr.rs
@@ -113,12 +113,12 @@ mod trivial {
         fn character(&self) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -250,12 +250,12 @@ mod generic {
         fn character(&self) -> Box<DynCharacter<'_, u8, ()>> {
             let ch: Box<DynCharacter<'_, u8, ()>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -343,8 +343,8 @@ mod description_from_doc_comment {
     impl QueryRoot {
         fn character(&self) -> Box<DynCharacter<'_>> {
             Box::new(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -416,8 +416,8 @@ mod explicit_name_and_description {
     impl QueryRoot {
         fn character(&self) -> Box<DynCharacter<'_>> {
             Box::new(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -517,12 +517,12 @@ mod explicit_scalar {
         fn character(&self) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -608,12 +608,12 @@ mod custom_scalar {
         fn character(&self) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -697,12 +697,12 @@ mod explicit_generic_scalar {
         fn character<__S: ScalarValue>(&self) -> Box<DynCharacter<'_, __S>> {
             let ch: Box<DynCharacter<'_, _>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -786,12 +786,12 @@ mod bounded_generic_scalar {
         fn character(&self) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             };
             ch
@@ -872,12 +872,12 @@ mod explicit_custom_context {
         fn character(&self, ctx: &CustomContext) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match ctx {
                 CustomContext::Human => Box::new(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Box::new(DroidCustomContext {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 _ => unimplemented!(),
             };
@@ -959,12 +959,12 @@ mod inferred_custom_context {
         fn character(&self, ctx: &CustomContext) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match ctx {
                 CustomContext::Human => Box::new(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Box::new(DroidCustomContext {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 _ => unimplemented!(),
             };
@@ -1042,8 +1042,8 @@ mod ignored_method {
     impl QueryRoot {
         fn character(&self) -> Box<DynCharacter<'_>> {
             Box::new(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -1134,12 +1134,12 @@ mod external_resolver {
         fn character(&self) -> Box<DynCharacter<'_>> {
             let ch: Box<DynCharacter<'_>> = match self {
                 Self::Human => Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Box::new(Droid {
-                    id: "?????".to_string(),
-                    primary_function: "???".to_string(),
+                    id: "?????".into(),
+                    primary_function: "???".into(),
                 }),
             };
             ch
@@ -1178,8 +1178,8 @@ mod external_resolver {
         let schema = schema(QueryRoot::Droid);
         let db = Database {
             droid: Some(Droid {
-                id: "droid-99".to_string(),
-                primary_function: "run".to_string(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         };
 
@@ -1250,15 +1250,15 @@ mod full_featured {
         fn character(&self, ctx: &CustomContext) -> Box<DynCharacter<'_, ()>> {
             let ch: Box<DynCharacter<'_, ()>> = match ctx {
                 CustomContext::Human => Box::new(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Box::new(DroidCustomContext {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 CustomContext::Ewok => Box::new(EwokCustomContext {
-                    id: "ewok-1".to_string(),
+                    id: "ewok-1".into(),
                     funny: true,
                 }),
             };
diff --git a/tests/integration/src/codegen/union_derive.rs b/tests/integration/src/codegen/union_derive.rs
index be6577e2..ffab8d91 100644
--- a/tests/integration/src/codegen/union_derive.rs
+++ b/tests/integration/src/codegen/union_derive.rs
@@ -97,12 +97,12 @@ mod trivial_enum {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -217,12 +217,12 @@ mod generic_enum {
         fn character(&self) -> Character<u8, ()> {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -317,7 +317,7 @@ mod generic_lifetime_enum {
             match self {
                 Self::Human => Character::A(LifetimeHuman { id: "human-32" }),
                 Self::Droid => Character::B(GenericDroid {
-                    id: "droid-99".to_string(),
+                    id: "droid-99".into(),
                     _t: PhantomData,
                 }),
             }
@@ -394,8 +394,8 @@ mod description_from_doc_comments {
     impl QueryRoot {
         fn character(&self) -> Character {
             Character::A(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -458,8 +458,8 @@ mod explicit_name_and_description {
     impl QueryRoot {
         fn character(&self) -> Character {
             Character::A(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -542,12 +542,12 @@ mod explicit_scalar {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -615,12 +615,12 @@ mod custom_scalar {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -688,12 +688,12 @@ mod explicit_generic_scalar {
         fn character<__S: ScalarValue>(&self) -> Character<__S> {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -759,12 +759,12 @@ mod bounded_generic_scalar {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
             }
         }
@@ -827,12 +827,12 @@ mod custom_context {
         fn character(&self, ctx: &CustomContext) -> Character {
             match ctx {
                 CustomContext::Human => Character::A(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Character::B(DroidCustomContext {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 _ => unimplemented!(),
             }
@@ -896,12 +896,12 @@ mod different_context {
         fn character(&self, ctx: &CustomContext) -> Character {
             match ctx {
                 CustomContext::Human => Character::A(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Character::B(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 _ => unimplemented!(),
             }
@@ -966,8 +966,8 @@ mod ignored_enum_variants {
     impl QueryRoot {
         fn character(&self) -> Character {
             Character::A(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             })
         }
     }
@@ -1053,8 +1053,8 @@ mod external_resolver_enum {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B,
             }
@@ -1093,8 +1093,8 @@ mod external_resolver_enum {
         let schema = schema(QueryRoot::Droid);
         let db = Database {
             droid: Some(Droid {
-                id: "droid-99".to_string(),
-                primary_function: "run".to_string(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         };
 
@@ -1144,12 +1144,12 @@ mod external_resolver_enum_variant {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 Self::Droid => Character::B(Droid {
-                    id: "?????".to_string(),
-                    primary_function: "???".to_string(),
+                    id: "?????".into(),
+                    primary_function: "???".into(),
                 }),
             }
         }
@@ -1187,8 +1187,8 @@ mod external_resolver_enum_variant {
         let schema = schema(QueryRoot::Droid);
         let db = Database {
             droid: Some(Droid {
-                id: "droid-99".to_string(),
-                primary_function: "run".to_string(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         };
 
@@ -1250,15 +1250,15 @@ mod full_featured_enum {
         fn character(&self, ctx: &CustomContext) -> Character<()> {
             match ctx {
                 CustomContext::Human => Character::A(HumanCustomContext {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 }),
                 CustomContext::Droid => Character::B(DroidCustomContext {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 }),
                 CustomContext::Ewok => Character::C(EwokCustomContext {
-                    id: "ewok-1".to_string(),
+                    id: "ewok-1".into(),
                     funny: true,
                 }),
             }
@@ -1409,7 +1409,7 @@ mod trivial_struct {
                     Self::Human => "human-32",
                     Self::Droid => "droid-99",
                 }
-                .to_string(),
+                .into(),
             }
         }
     }
@@ -1432,8 +1432,8 @@ mod trivial_struct {
         let schema = schema(QueryRoot::Human);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             droid: None,
         };
@@ -1453,8 +1453,8 @@ mod trivial_struct {
         let db = Database {
             human: None,
             droid: Some(Droid {
-                id: "droid-99".to_string(),
-                primary_function: "run".to_string(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         };
 
@@ -1478,8 +1478,8 @@ mod trivial_struct {
         let schema = schema(QueryRoot::Human);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             droid: None,
         };
@@ -1501,8 +1501,8 @@ mod trivial_struct {
         let schema = schema(QueryRoot::Human);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             droid: None,
         };
@@ -1524,8 +1524,8 @@ mod trivial_struct {
         let schema = schema(QueryRoot::Human);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             droid: None,
         };
@@ -1570,7 +1570,7 @@ mod generic_struct {
     impl QueryRoot {
         fn character(&self) -> Character<u8, ()> {
             Character {
-                id: "human-32".to_string(),
+                id: "human-32".into(),
                 _s: PhantomData,
             }
         }
@@ -1590,8 +1590,8 @@ mod generic_struct {
         let schema = schema(QueryRoot);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
         };
 
@@ -1678,7 +1678,7 @@ mod full_featured_struct {
                     Self::Human => "human-32",
                     Self::Droid => "droid-99",
                 }
-                .to_string(),
+                .into(),
                 _s: PhantomData,
             }
         }
@@ -1702,8 +1702,8 @@ mod full_featured_struct {
         let schema = schema(QueryRoot::Human);
         let db = Database {
             human: Some(Human {
-                id: "human-32".to_string(),
-                home_planet: "earth".to_string(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             droid: None,
         };
@@ -1723,8 +1723,8 @@ mod full_featured_struct {
         let db = Database {
             human: None,
             droid: Some(Droid {
-                id: "droid-99".to_string(),
-                primary_function: "run".to_string(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         };
 
@@ -1804,12 +1804,12 @@ mod issue_845 {
         fn character(&self) -> Character {
             match self {
                 Self::Human => Character::A(Box::new(Human {
-                    id: "human-32".to_string(),
-                    home_planet: "earth".to_string(),
+                    id: "human-32".into(),
+                    home_planet: "earth".into(),
                 })),
                 Self::Droid => Character::B(Arc::new(Droid {
-                    id: "droid-99".to_string(),
-                    primary_function: "run".to_string(),
+                    id: "droid-99".into(),
+                    primary_function: "run".into(),
                 })),
             }
         }
diff --git a/tests/integration/src/custom_scalar.rs b/tests/integration/src/custom_scalar.rs
index b9acecbc..1d1c26ec 100644
--- a/tests/integration/src/custom_scalar.rs
+++ b/tests/integration/src/custom_scalar.rs
@@ -1,4 +1,4 @@
-use std::{convert::TryInto as _, fmt, pin::Pin};
+use std::{fmt, pin::Pin};
 
 use futures::{stream, Stream};
 use juniper::{
@@ -104,7 +104,7 @@ mod long {
     pub(super) fn from_input(v: &InputValue<MyScalarValue>) -> Result<Long, String> {
         v.as_scalar_value::<i64>()
             .copied()
-            .ok_or_else(|| format!("Expected `MyScalarValue::Long`, found: {}", v))
+            .ok_or_else(|| format!("Expected `MyScalarValue::Long`, found: {v}"))
     }
 
     pub(super) fn parse_token(value: ScalarToken<'_>) -> ParseScalarResult<MyScalarValue> {
@@ -153,7 +153,7 @@ where
 
     assert_eq!(errs, []);
 
-    println!("Result: {:?}", result);
+    println!("Result: {result:?}");
 
     let obj = result.as_object_value().expect("Result is not an object");
 
diff --git a/tests/integration/src/issue_407.rs b/tests/integration/src/issue_407.rs
index 245398c3..a8a4ef13 100644
--- a/tests/integration/src/issue_407.rs
+++ b/tests/integration/src/issue_407.rs
@@ -31,12 +31,12 @@ struct Droid {
 impl Query {
     fn characters() -> Vec<CharacterValue> {
         let human = Human {
-            id: "1".to_string(),
-            name: "Han Solo".to_string(),
+            id: "1".into(),
+            name: "Han Solo".into(),
         };
         let droid = Droid {
-            id: "2".to_string(),
-            serial_number: "234532545235".to_string(),
+            id: "2".into(),
+            serial_number: "234532545235".into(),
         };
         vec![Into::into(human), Into::into(droid)]
     }
diff --git a/tests/integration/src/issue_798.rs b/tests/integration/src/issue_798.rs
index fed322fc..40252406 100644
--- a/tests/integration/src/issue_798.rs
+++ b/tests/integration/src/issue_798.rs
@@ -42,12 +42,12 @@ impl Query {
     fn field(&self) -> FieldResult {
         match self {
             Self::Human => FieldResult::Human(Human {
-                id: "human-32".to_owned(),
-                home_planet: "earth".to_owned(),
+                id: "human-32".into(),
+                home_planet: "earth".into(),
             }),
             Self::Droid => FieldResult::Droid(Droid {
-                id: "droid-99".to_owned(),
-                primary_function: "run".to_owned(),
+                id: "droid-99".into(),
+                primary_function: "run".into(),
             }),
         }
     }
diff --git a/tests/integration/src/issue_922.rs b/tests/integration/src/issue_922.rs
index fd28b45f..1a89a68e 100644
--- a/tests/integration/src/issue_922.rs
+++ b/tests/integration/src/issue_922.rs
@@ -14,11 +14,11 @@ impl Query {
         vec![
             Into::into(Human {
                 id: 0,
-                name: "human-32".to_owned(),
+                name: "human-32".into(),
             }),
             Into::into(Droid {
                 id: 1,
-                name: "R2-D2".to_owned(),
+                name: "R2-D2".into(),
             }),
         ]
     }
diff --git a/tests/integration/src/issue_945.rs b/tests/integration/src/issue_945.rs
index 369e660b..42458313 100644
--- a/tests/integration/src/issue_945.rs
+++ b/tests/integration/src/issue_945.rs
@@ -13,8 +13,8 @@ impl Query {
     fn artoo() -> Character {
         Character::Droid(Droid {
             id: 1,
-            name: "R2-D2".to_owned(),
-            sensor_color: "red".to_owned(),
+            name: "R2-D2".into(),
+            sensor_color: "red".into(),
         })
     }
 }
diff --git a/tests/integration/src/pre_parse.rs b/tests/integration/src/pre_parse.rs
index ec987eca..28415ffc 100644
--- a/tests/integration/src/pre_parse.rs
+++ b/tests/integration/src/pre_parse.rs
@@ -64,15 +64,10 @@ async fn query_document_can_be_pre_parsed() {
     let errors = validate_input_values(&graphql_vars! {}, operation, &root_node.schema);
     assert!(errors.is_empty());
 
-    let (_, errors) = execute_validated_query_async(
-        &document,
-        operation,
-        root_node,
-        &graphql_vars! {},
-        &Context {},
-    )
-    .await
-    .unwrap();
+    let (_, errors) =
+        execute_validated_query_async(&document, operation, root_node, &graphql_vars! {}, &Context)
+            .await
+            .unwrap();
 
     assert!(errors.len() == 0);
 }
@@ -92,7 +87,7 @@ async fn subscription_document_can_be_pre_parsed() {
         &operation,
         &root_node,
         &graphql_vars! {},
-        &Context {},
+        &Context,
     )
     .map_ok(|(stream, errors)| juniper_subscriptions::Connection::from_stream(stream, errors))
     .await