From 1958e54e9012d553a952ae3d070b6fab7e8289f9 Mon Sep 17 00:00:00 2001
From: Paul Bakker <pbakker@netflix.com>
Date: Mon, 19 Apr 2021 16:53:59 -0700
Subject: [PATCH 1/2] Fix to prevent stackoverflow when a cycle in an input
 type exists.

---
 .../dgs/codegen/RequiredTypeCollector.kt      |  6 ++--
 .../graphql/dgs/codegen/ClientApiGenTest.kt   | 36 +++++++++++++++++++
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/RequiredTypeCollector.kt b/graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/RequiredTypeCollector.kt
index ed7d33543..f718d26b5 100644
--- a/graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/RequiredTypeCollector.kt
+++ b/graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/RequiredTypeCollector.kt
@@ -42,16 +42,18 @@ class RequiredTypeCollector(
 
         NodeTraverser().postOrder(
             object : NodeVisitorStub() {
+                val visitedTypes = mutableSetOf<String>()
+
                 override fun visitInputObjectTypeDefinition(
                     node: InputObjectTypeDefinition,
                     context: TraverserContext<Node<Node<*>>>
                 ): TraversalControl {
                     required += node.name
 
-                    node.inputValueDefinitions.forEach {
+                    node.inputValueDefinitions.filter { !visitedTypes.contains(it.name) }.forEach {
+                        visitedTypes.add(it.name)
                         it.type.findTypeDefinition(document)?.accept(context, this)
                     }
-
                     return TraversalControl.CONTINUE
                 }
 
diff --git a/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/ClientApiGenTest.kt b/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/ClientApiGenTest.kt
index 51dcba285..db3c752de 100644
--- a/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/ClientApiGenTest.kt
+++ b/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/ClientApiGenTest.kt
@@ -118,6 +118,42 @@ class ClientApiGenTest {
         assertCompilesJava(codeGenResult.clientProjections.plus(codeGenResult.queryTypes).plus(codeGenResult.dataTypes))
     }
 
+    @Test
+    fun generateRecursiveInputTypes() {
+
+        val schema = """
+            type Query {
+                movies(filter: MovieQuery): [String]
+            }
+            
+            input MovieQuery {
+                booleanQuery: BooleanQuery!
+                titleFilter: String
+            }
+            
+            input BooleanQuery {
+                first: MovieQuery!
+                second: MovieQuery!
+            }
+        """.trimIndent()
+
+        val codeGenResult = CodeGen(
+            CodeGenConfig(
+                schemas = setOf(schema),
+                packageName = basePackageName,
+                generateDataTypes = false,
+                generateClientApi = true,
+                includeQueries = mutableSetOf("movies")
+            )
+        ).generate() as CodeGenResult
+
+        assertThat(codeGenResult.dataTypes.size).isEqualTo(2)
+        assertThat(codeGenResult.dataTypes[0].typeSpec.name).isEqualTo("MovieQuery")
+        assertThat(codeGenResult.dataTypes[1].typeSpec.name).isEqualTo("BooleanQuery")
+
+        assertCompilesJava(codeGenResult.dataTypes)
+    }
+
     @Test
     fun generateMutationAddsNullChecksDuringInit() {
 

From 3e47a7e69aec28a795e4dffc24475a47019030f8 Mon Sep 17 00:00:00 2001
From: Paul Bakker <pbakker@netflix.com>
Date: Mon, 19 Apr 2021 17:01:55 -0700
Subject: [PATCH 2/2] Added test for Kotlin for recursive input types

---
 .../dgs/codegen/KotlinClientApiGenTest.kt     | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/KotlinClientApiGenTest.kt b/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/KotlinClientApiGenTest.kt
index e4a87c661..ec4e97291 100644
--- a/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/KotlinClientApiGenTest.kt
+++ b/graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/KotlinClientApiGenTest.kt
@@ -125,6 +125,42 @@ class KotlinClientApiGenTest {
         assertCompilesKotlin(codeGenResult.clientProjections)
     }
 
+    @Test
+    fun generateRecursiveInputTypes() {
+
+        val schema = """
+            type Query {
+                movies(filter: MovieQuery): [String]
+            }
+            
+            input MovieQuery {
+                booleanQuery: BooleanQuery!
+                titleFilter: String
+            }
+            
+            input BooleanQuery {
+                first: MovieQuery!
+                second: MovieQuery!
+            }
+        """.trimIndent()
+
+        val codeGenResult = CodeGen(
+            CodeGenConfig(
+                schemas = setOf(schema),
+                packageName = basePackageName,
+                language = Language.KOTLIN,
+                generateClientApi = true,
+            )
+        ).generate() as KotlinCodeGenResult
+
+        assertThat(codeGenResult.dataTypes.size).isEqualTo(2)
+        val movieQuery = codeGenResult.dataTypes[0].members[0] as TypeSpec
+        assertThat(movieQuery.name).isEqualTo("MovieQuery")
+
+        val booleanQuery = codeGenResult.dataTypes[1].members[0] as TypeSpec
+        assertThat(booleanQuery.name).isEqualTo("BooleanQuery")
+    }
+
     @Test
     fun interfaceReturnTypes() {