From 7e2a671ca52fb22c5d86d5d2f5ffe7fbafaceb96 Mon Sep 17 00:00:00 2001
From: rstoyanchev <rossen.stoyanchev@broadcom.com>
Date: Mon, 18 Mar 2024 16:32:07 +0000
Subject: [PATCH] ClassNameTypeResolver resolves to concrete types only

See gh-924
---
 .../execution/ClassNameTypeResolver.java      |  8 ++++---
 .../execution/ClassNameTypeResolverTests.java | 23 +++++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/spring-graphql/src/main/java/org/springframework/graphql/execution/ClassNameTypeResolver.java b/spring-graphql/src/main/java/org/springframework/graphql/execution/ClassNameTypeResolver.java
index c6881521..2427cf8a 100644
--- a/spring-graphql/src/main/java/org/springframework/graphql/execution/ClassNameTypeResolver.java
+++ b/spring-graphql/src/main/java/org/springframework/graphql/execution/ClassNameTypeResolver.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import java.util.function.Function;
 import graphql.TypeResolutionEnvironment;
 import graphql.schema.GraphQLObjectType;
 import graphql.schema.GraphQLSchema;
+import graphql.schema.GraphQLType;
 import graphql.schema.TypeResolver;
 
 import org.springframework.lang.Nullable;
@@ -97,8 +98,9 @@ public class ClassNameTypeResolver implements TypeResolver {
 		}
 
 		name = this.classNameExtractor.apply(clazz);
-		if (schema.containsType(name)) {
-			return schema.getObjectType(name);
+		GraphQLType type = schema.getType(name);
+		if (type instanceof GraphQLObjectType objectType) {
+			return objectType;
 		}
 
 		for (Class<?> interfaceType : clazz.getInterfaces()) {
diff --git a/spring-graphql/src/test/java/org/springframework/graphql/execution/ClassNameTypeResolverTests.java b/spring-graphql/src/test/java/org/springframework/graphql/execution/ClassNameTypeResolverTests.java
index 93ec4e59..a92a7c40 100644
--- a/spring-graphql/src/test/java/org/springframework/graphql/execution/ClassNameTypeResolverTests.java
+++ b/spring-graphql/src/test/java/org/springframework/graphql/execution/ClassNameTypeResolverTests.java
@@ -97,6 +97,7 @@ public class ClassNameTypeResolverTests {
 				graphQlSetup.queryFetcher("animals", env -> animalList).toGraphQlService();
 
 		ResponseHelper response = ResponseHelper.forResponse(service.execute(document));
+		assertThat(response.errorCount()).isEqualTo(0);
 
 		Mammal mammal = response.toEntity("animals[0]", Dog.class);
 		assertThat(mammal.isHerbivore()).isEqualTo(false);
@@ -134,6 +135,7 @@ public class ClassNameTypeResolverTests {
 						.toGraphQlService();
 
 		ResponseHelper response = ResponseHelper.forResponse(service.execute(document));
+		assertThat(response.errorCount()).isEqualTo(0);
 
 		Animal animal = response.toEntity("sightings[0]", GrayWolf.class);
 		assertThat(animal.getName()).isEqualTo("Gray Wolf");
@@ -142,6 +144,27 @@ public class ClassNameTypeResolverTests {
 		assertThat(tree.getFamily()).isEqualTo("Redwood");
 	}
 
+	@Test
+	void javaTypeResolvesToSchemaInterfaceOnly() {
+
+		String document = """
+				query Animals {
+				  animals {
+					__typename
+					name
+				  }
+				}
+				""";
+
+		TestExecutionGraphQlService service =
+				graphQlSetup.queryFetcher("animals", env -> List.of(new BaseAnimal("Fox"))).toGraphQlService();
+
+		ResponseHelper response = ResponseHelper.forResponse(service.execute(document));
+		assertThat(response.errorCount()).isEqualTo(1);
+		assertThat(response.error(0).message()).contains("Could not determine the exact type of 'Animal'");
+	}
+
+
 
 	interface Animal {