Allow different Scalar for GraphQLScalarValue (#807)

* allow setting scalar in macro

* rustfmt

* added changes to changelog

* added test cases

integration_tests/juniper_tests/src/codegen/derive_scalar.rs

@@ -0,0 +1,139 @@
+use crate::custom_scalar::MyScalarValue;
+use juniper::{
+    execute, EmptyMutation, EmptySubscription, FromInputValue, InputValue, RootNode, ToInputValue,
+    Value, Variables,
+};
+
+#[derive(Debug, PartialEq, Eq, Hash, juniper::GraphQLScalarValue)]
+#[graphql(transparent, scalar = MyScalarValue)]
+pub struct LargeId(i64);
+
+#[derive(juniper::GraphQLObject)]
+#[graphql(scalar = MyScalarValue)]
+struct User {
+    id: LargeId,
+}
+
+struct Query;
+
+#[juniper::graphql_object(scalar = MyScalarValue)]
+impl Query {
+    fn user() -> User {
+        User { id: LargeId(0) }
+    }
+}
+
+struct Mutation;
+
+#[juniper::graphql_object(scalar = MyScalarValue)]
+impl Mutation {
+    fn change_user(id: LargeId) -> User {
+        User { id }
+    }
+}
+
+#[test]
+fn test_scalar_value_large_id() {
+    let num: i64 = 4294967297;
+
+    let input_integer: InputValue<MyScalarValue> =
+        serde_json::from_value(serde_json::json!(num)).unwrap();
+
+    let output: LargeId =
+        FromInputValue::<MyScalarValue>::from_input_value(&input_integer).unwrap();
+    assert_eq!(output, LargeId(num));
+
+    let id = LargeId(num);
+    let output = ToInputValue::<MyScalarValue>::to_input_value(&id);
+    assert_eq!(output, InputValue::scalar(num));
+}
+
+#[tokio::test]
+async fn test_scalar_value_large_query() {
+    let schema = RootNode::<'_, _, _, _, MyScalarValue>::new_with_scalar_value(
+        Query,
+        EmptyMutation::<()>::new(),
+        EmptySubscription::<()>::new(),
+    );
+
+    let doc = r#"
+        query {
+            user { id }
+        }"#;
+
+    assert_eq!(
+        execute(doc, None, &schema, &Variables::<MyScalarValue>::new(), &()).await,
+        Ok((
+            Value::object(
+                vec![(
+                    "user",
+                    Value::object(
+                        vec![("id", Value::<MyScalarValue>::scalar(0_i64)),]
+                            .into_iter()
+                            .collect(),
+                    ),
+                )]
+                .into_iter()
+                .collect()
+            ),
+            vec![]
+        ))
+    );
+}
+
+#[tokio::test]
+async fn test_scalar_value_large_mutation() {
+    let schema = RootNode::<'_, _, _, _, MyScalarValue>::new_with_scalar_value(
+        Query,
+        Mutation,
+        EmptySubscription::<()>::new(),
+    );
+
+    let doc = r#"
+        mutation {
+            changeUser(id: 1) { id }
+        }"#;
+
+    assert_eq!(
+        execute(doc, None, &schema, &Variables::<MyScalarValue>::new(), &()).await,
+        Ok((
+            Value::object(
+                vec![(
+                    "changeUser",
+                    Value::object(
+                        vec![("id", Value::<MyScalarValue>::scalar(1_i64)),]
+                            .into_iter()
+                            .collect(),
+                    ),
+                )]
+                .into_iter()
+                .collect()
+            ),
+            vec![]
+        ))
+    );
+
+    let doc = r#"
+        mutation {
+            changeUser(id: 4294967297) { id }
+        }"#;
+
+    assert_eq!(
+        execute(doc, None, &schema, &Variables::<MyScalarValue>::new(), &()).await,
+        Ok((
+            Value::object(
+                vec![(
+                    "changeUser",
+                    Value::object(
+                        vec![("id", Value::<MyScalarValue>::scalar(4294967297_i64)),]
+                            .into_iter()
+                            .collect(),
+                    ),
+                )]
+                .into_iter()
+                .collect()
+            ),
+            vec![]
+        ))
+    );
+}

integration_tests/juniper_tests/src/codegen/mod.rs

@@ -2,6 +2,7 @@ mod derive_enum;
 mod derive_input_object;
 mod derive_object;
 mod derive_object_with_raw_idents;
+mod derive_scalar;
 mod impl_object;
 mod impl_scalar;
 mod interface_attr;

juniper/CHANGELOG.md

@@ -39,6 +39,8 @@
 
 - Implement `IntoFieldError` for `std::convert::Infallible`. ([#796](https://github.com/graphql-rust/juniper/pull/796))
 
+- Allow using `#[graphql(Scalar = DefaultScalarValue)]` for derive macro `GraphQLScalarValue` ([#807](https://github.com/graphql-rust/juniper/pull/807))
+
 ## Fixes
 
 - Massively improved the `#[graphql_union]` proc macro. ([#666](https://github.com/graphql-rust/juniper/pull/666)):

juniper_codegen/src/derive_scalar_value.rs

@@ -12,6 +12,7 @@ struct TransparentAttributes {
     transparent: Option<bool>,
     name: Option<String>,
     description: Option<String>,
+    scalar: Option<syn::Type>,
 }
 
 impl syn::parse::Parse for TransparentAttributes {
@@ -20,6 +21,7 @@ impl syn::parse::Parse for TransparentAttributes {
             transparent: None,
             name: None,
             description: None,
+            scalar: None,
         };
 
         while !input.is_empty() {
@@ -38,6 +40,11 @@ impl syn::parse::Parse for TransparentAttributes {
                 "transparent" => {
                     output.transparent = Some(true);
                 }
+                "scalar" | "Scalar" => {
+                    input.parse::<token::Eq>()?;
+                    let val = input.parse::<syn::Type>()?;
+                    output.scalar = Some(val);
+                }
                 _ => return Err(syn::Error::new(ident.span(), "unknown attribute")),
             }
             input.try_parse::<token::Comma>()?;
@@ -99,22 +106,34 @@ fn impl_scalar_struct(
         None => quote!(),
     };
 
+    let scalar = attrs
+        .scalar
+        .as_ref()
+        .map(|s| quote!( #s ))
+        .unwrap_or_else(|| quote!(__S));
+
+    let impl_generics = attrs
+        .scalar
+        .as_ref()
+        .map(|_| quote!())
+        .unwrap_or_else(|| quote!(<__S>));
+
     let _async = quote!(
-        impl<__S> ::juniper::GraphQLValueAsync<__S> for #ident
+        impl#impl_generics ::juniper::GraphQLValueAsync<#scalar> for #ident
         where
             Self: Sync,
             Self::TypeInfo: Sync,
             Self::Context: Sync,
-            __S: ::juniper::ScalarValue + Send + Sync,
+            #scalar: ::juniper::ScalarValue + Send + Sync,
         {
             fn resolve_async<'a>(
                 &'a self,
                 info: &'a Self::TypeInfo,
-                selection_set: Option<&'a [::juniper::Selection<__S>]>,
+                selection_set: Option<&'a [::juniper::Selection<#scalar>]>,
-                executor: &'a ::juniper::Executor<Self::Context, __S>,
+                executor: &'a ::juniper::Executor<Self::Context, #scalar>,
-            ) -> ::juniper::BoxFuture<'a, ::juniper::ExecutionResult<__S>> {
+            ) -> ::juniper::BoxFuture<'a, ::juniper::ExecutionResult<#scalar>> {
                 use ::juniper::futures::future;
-                let v = ::juniper::GraphQLValue::resolve(self, info, selection_set, executor);
+                let v = ::juniper::GraphQLValue::<#scalar>::resolve(self, info, selection_set, executor);
                 Box::pin(future::ready(v))
             }
         }
@@ -123,9 +142,9 @@ fn impl_scalar_struct(
     let content = quote!(
         #_async
 
-        impl<S> ::juniper::GraphQLType<S> for #ident
+        impl#impl_generics ::juniper::GraphQLType<#scalar> for #ident
         where
-            S: ::juniper::ScalarValue,
+            #scalar: ::juniper::ScalarValue,
         {
             fn name(_: &Self::TypeInfo) -> Option<&'static str> {
                 Some(#name)
@@ -133,10 +152,10 @@ fn impl_scalar_struct(
 
             fn meta<'r>(
                 info: &Self::TypeInfo,
-                registry: &mut ::juniper::Registry<'r, S>,
+                registry: &mut ::juniper::Registry<'r, #scalar>,
-            ) -> ::juniper::meta::MetaType<'r, S>
+            ) -> ::juniper::meta::MetaType<'r, #scalar>
             where
-                S: 'r,
+                #scalar: 'r,
             {
                 registry.build_scalar_type::<Self>(info)
                     #description
@@ -144,59 +163,63 @@ fn impl_scalar_struct(
             }
         }
 
-        impl<S> ::juniper::GraphQLValue<S> for #ident
+        impl#impl_generics ::juniper::GraphQLValue<#scalar> for #ident
         where
-            S: ::juniper::ScalarValue,
+            #scalar: ::juniper::ScalarValue,
         {
             type Context = ();
             type TypeInfo = ();
 
             fn type_name<'__i>(&self, info: &'__i Self::TypeInfo) -> Option<&'__i str> {
-                <Self as ::juniper::GraphQLType<S>>::name(info)
+                <Self as ::juniper::GraphQLType<#scalar>>::name(info)
             }
 
             fn resolve(
                 &self,
                 info: &(),
-                selection: Option<&[::juniper::Selection<S>]>,
+                selection: Option<&[::juniper::Selection<#scalar>]>,
-                executor: &::juniper::Executor<Self::Context, S>,
+                executor: &::juniper::Executor<Self::Context, #scalar>,
-            ) -> ::juniper::ExecutionResult<S> {
+            ) -> ::juniper::ExecutionResult<#scalar> {
-                ::juniper::GraphQLValue::resolve(&self.0, info, selection, executor)
+                ::juniper::GraphQLValue::<#scalar>::resolve(&self.0, info, selection, executor)
             }
         }
 
-        impl<S> ::juniper::ToInputValue<S> for #ident
+        impl#impl_generics ::juniper::ToInputValue<#scalar> for #ident
         where
-            S: ::juniper::ScalarValue,
+            #scalar: ::juniper::ScalarValue,
         {
-            fn to_input_value(&self) -> ::juniper::InputValue<S> {
+            fn to_input_value(&self) -> ::juniper::InputValue<#scalar> {
-                ::juniper::ToInputValue::to_input_value(&self.0)
+                ::juniper::ToInputValue::<#scalar>::to_input_value(&self.0)
             }
         }
 
-        impl<S> ::juniper::FromInputValue<S> for #ident
+        impl#impl_generics ::juniper::FromInputValue<#scalar> for #ident
         where
-            S: ::juniper::ScalarValue,
+            #scalar: ::juniper::ScalarValue,
         {
-            fn from_input_value(v: &::juniper::InputValue<S>) -> Option<#ident> {
+            fn from_input_value(v: &::juniper::InputValue<#scalar>) -> Option<#ident> {
-                let inner: #inner_ty = ::juniper::FromInputValue::from_input_value(v)?;
+                let inner: #inner_ty = ::juniper::FromInputValue::<#scalar>::from_input_value(v)?;
                 Some(#ident(inner))
             }
         }
 
-        impl<S> ::juniper::ParseScalarValue<S> for #ident
+        impl#impl_generics ::juniper::ParseScalarValue<#scalar> for #ident
         where
-            S: ::juniper::ScalarValue,
+            #scalar: ::juniper::ScalarValue,
         {
             fn from_str<'a>(
                 value: ::juniper::parser::ScalarToken<'a>,
-            ) -> ::juniper::ParseScalarResult<'a, S> {
+            ) -> ::juniper::ParseScalarResult<'a, #scalar> {
-                <#inner_ty as ::juniper::ParseScalarValue<S>>::from_str(value)
+                <#inner_ty as ::juniper::ParseScalarValue<#scalar>>::from_str(value)
             }
         }
 
-        impl<S: ::juniper::ScalarValue> ::juniper::marker::IsOutputType<S> for #ident { }
+        impl#impl_generics ::juniper::marker::IsOutputType<#scalar> for #ident
-        impl<S: ::juniper::ScalarValue> ::juniper::marker::IsInputType<S> for #ident { }
+            where #scalar: ::juniper::ScalarValue,
+        { }
+        impl#impl_generics ::juniper::marker::IsInputType<#scalar> for #ident
+            where #scalar: ::juniper::ScalarValue,
+        { }
     );
 
     Ok(content)