From e98d1df630088de1772b3d670852b34b00bbcf56 Mon Sep 17 00:00:00 2001
From: Johan ROUVE <johan.rouve@happn.fr>
Date: Tue, 9 Mar 2021 14:53:27 +0100
Subject: [PATCH 1/2] Remove error when DataFetcherResult is not the root type

---
 .../kotlin/graphql/kickstart/tools/TypeClassMatcher.kt     | 4 ----
 .../kotlin/graphql/kickstart/tools/EndToEndSpecHelper.kt   | 7 ++++++-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/main/kotlin/graphql/kickstart/tools/TypeClassMatcher.kt b/src/main/kotlin/graphql/kickstart/tools/TypeClassMatcher.kt
index 4f4a460f..840c4a19 100644
--- a/src/main/kotlin/graphql/kickstart/tools/TypeClassMatcher.kt
+++ b/src/main/kotlin/graphql/kickstart/tools/TypeClassMatcher.kt
@@ -32,10 +32,6 @@ internal class TypeClassMatcher(private val definitionsByName: Map<String, TypeD
                 throw error(potentialMatch, "${DataFetcherResult::class.java.name} can only be used as a return type")
             }
 
-            if (!root) {
-                throw error(potentialMatch, "${DataFetcherResult::class.java.name} can only be used at the top level of a return type")
-            }
-
             realType = potentialMatch.generic.unwrapGenericType(realType.actualTypeArguments.first())
 
             if (realType is ParameterizedType && potentialMatch.generic.isTypeAssignableFromRawClass(realType, DataFetcherResult::class.java)) {
diff --git a/src/test/kotlin/graphql/kickstart/tools/EndToEndSpecHelper.kt b/src/test/kotlin/graphql/kickstart/tools/EndToEndSpecHelper.kt
index e9480e40..8047a1ae 100644
--- a/src/test/kotlin/graphql/kickstart/tools/EndToEndSpecHelper.kt
+++ b/src/test/kotlin/graphql/kickstart/tools/EndToEndSpecHelper.kt
@@ -76,6 +76,7 @@ type Query {
 
     propertyField: String!
     dataFetcherResult: Item!
+    dataFetcherResultItems: [Item!]!
 
     coroutineItems: [Item!]!
 
@@ -302,6 +303,10 @@ class Query : GraphQLQueryResolver, ListListResolver<String>() {
         return DataFetcherResult.newResult<Item>().data(items.first()).build()
     }
 
+    fun dataFetcherResultItems(): List<DataFetcherResult<Item>> {
+        return listOf(DataFetcherResult.newResult<Item>().data(items.first()).build())
+    }
+
     suspend fun coroutineItems(): List<Item> = CompletableDeferred(items).await()
 
     fun arrayItems() = items.toTypedArray()
@@ -329,7 +334,7 @@ class Mutation : GraphQLMutationResolver {
     }
 
     fun saveUser(userInput: UserInput): String {
-        return userInput.name + "/" + userInput.password;
+        return userInput.name + "/" + userInput.password
     }
 
     class UserInput {

From 0bb2853be2515e31ab6d0227bf66948b3d046bc0 Mon Sep 17 00:00:00 2001
From: Johan ROUVE <johan.rouve@happn.fr>
Date: Tue, 9 Mar 2021 15:07:35 +0100
Subject: [PATCH 2/2] Add test on generated schema

---
 .../graphql/kickstart/tools/EndToEndTest.kt       | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/test/kotlin/graphql/kickstart/tools/EndToEndTest.kt b/src/test/kotlin/graphql/kickstart/tools/EndToEndTest.kt
index b67d6973..6ca764c1 100644
--- a/src/test/kotlin/graphql/kickstart/tools/EndToEndTest.kt
+++ b/src/test/kotlin/graphql/kickstart/tools/EndToEndTest.kt
@@ -532,6 +532,21 @@ class EndToEndTest {
         assertEquals(data["dataFetcherResult"], mapOf("name" to "item1"))
     }
 
+    @Test
+    fun `generated schema supports list of DataFetcherResult`() {
+        val data = assertNoGraphQlErrors(gql) {
+            """
+            {
+                dataFetcherResultItems {
+                    name
+                }
+            }
+            """
+        }
+
+        assertEquals(data["dataFetcherResultItems"], listOf(mapOf("name" to "item1")))
+    }
+
     @Test
     fun `generated schema supports Kotlin suspend functions`() {
         val data = assertNoGraphQlErrors(gql) {