From 737c4c718475d8058b0b82a89b8703e406e22ef2 Mon Sep 17 00:00:00 2001
From: nWacky <gosha.evtushenko@gmail.com>
Date: Fri, 1 Nov 2019 17:51:25 +0300
Subject: [PATCH] Add `resolve_into_type_async`

---
 examples/warp_async/Cargo.toml   |  9 ++++---
 juniper/src/types/async_await.rs | 45 +++++++++++++++++++++++---------
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/examples/warp_async/Cargo.toml b/examples/warp_async/Cargo.toml
index 7568b799..d3085ce4 100644
--- a/examples/warp_async/Cargo.toml
+++ b/examples/warp_async/Cargo.toml
@@ -13,7 +13,10 @@ warp = "0.1.19"
 futures-preview = { version = "0.3.0-alpha.19", features = ["async-await", "compat"] }
 reqwest = "0.9.19"
 
-juniper_codegen = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
-juniper = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
-juniper_warp = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
+#juniper_codegen = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
+#juniper = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
+#juniper_warp = { git = "https://github.com/graphql-rust/juniper", branch = "async-await", features = ["async"] }
 
+juniper_codegen = { path = "../../juniper_codegen", features = ["async"] }
+juniper = { path = "../../juniper", features = ["async"] }
+juniper_warp = { path = "../../juniper_warp", features = ["async"] }
diff --git a/juniper/src/types/async_await.rs b/juniper/src/types/async_await.rs
index 3b7971a9..6e87a8cb 100644
--- a/juniper/src/types/async_await.rs
+++ b/juniper/src/types/async_await.rs
@@ -1,3 +1,4 @@
+use async_trait::async_trait;
 use crate::{
     ast::{Directive, FromInputValue, InputValue, Selection},
     value::{Object, ScalarRefValue, ScalarValue, Value},
@@ -12,7 +13,8 @@ use crate::BoxFuture;
 
 use super::base::{is_excluded, merge_key_into, Arguments, GraphQLType};
 
-#[async_trait]
+// todo: async trait
+//#[async_trait]
 pub trait GraphQLTypeAsync<S>: GraphQLType<S> + Send + Sync
 where
     Self::Context: Send + Sync,
@@ -20,28 +22,47 @@ where
     S: ScalarValue + Send + Sync,
     for<'b> &'b S: ScalarRefValue<'b>,
 {
-    async fn resolve_field_async<'a>(
+    fn resolve_field_async<'a>(
         &'a self,
         info: &'a Self::TypeInfo,
         field_name: &'a str,
-        arguments: &'a Arguments<S>,
-        executor: &'a Executor<Self::Context, S>,
-    ) -> ExecutionResult<S> {
+        arguments: &'a Arguments<'a, S>,
+        executor: &'a Executor<'a, Self::Context, S>,
+    ) ->  BoxFuture<'a, ExecutionResult<S>> {
         panic!("resolve_field must be implemented by object types");
     }
 
-    async fn resolve_async<'a>(
+    fn resolve_async<'a>(
         &'a self,
         info: &'a Self::TypeInfo,
-        selection_set: Option<&'a [Selection<S>]>,
-        executor: &'a Executor<Self::Context, S>,
-    ) -> Value<S> {
+        selection_set: Option<&'a [Selection<'a, S>]>,
+        executor: &'a Executor<'a, Self::Context, S>,
+    ) -> BoxFuture<'a, Value<S>> {
         if let Some(selection_set) = selection_set {
             resolve_selection_set_into_async(self, info, selection_set, executor)
         } else {
             panic!("resolve() must be implemented by non-object output types");
         }
     }
+
+    fn resolve_into_type_async<'a>(
+        &'a self,
+        info: &'a Self::TypeInfo,
+        type_name: &str,
+        selection_set: Option<&'a [Selection<'a, S>]>,
+        executor: &'a Executor<'a, Self::Context, S>,
+    ) ->  BoxFuture<'a, ExecutionResult<S>> {
+        if Self::name(info).unwrap() == type_name {
+            Box::pin(
+                async move {
+                    let x = self.resolve_async(info, selection_set, executor).await;
+                    Ok(x)
+                }
+            )
+        } else {
+            panic!("resolve_into_type_async must be implemented by unions and interfaces");
+        }
+    }
 }
 
 // Wrapper function around resolve_selection_set_into_async_recursive.
@@ -161,7 +182,7 @@ where
                 let response_name = response_name.to_string();
                 let field_future = async move {
                     // TODO: implement custom future type instead of
-                    // two-level boxing.
+                    //       two-level boxing.
                     let res = instance
                         .resolve_field_async(info, f.name.item, &args, &sub_exec)
                         .await;
@@ -226,12 +247,12 @@ where
                 if let Some(ref type_condition) = fragment.type_condition {
                     // FIXME: implement async version.
 
-                    let sub_result = instance.resolve_into_type(
+                    let sub_result = instance.resolve_into_type_async(
                         info,
                         type_condition.item,
                         Some(&fragment.selection_set[..]),
                         &sub_exec,
-                    );
+                    ).await;
 
                     if let Ok(Value::Object(obj)) = sub_result {
                         for (k, v) in obj {