Replace DataFetcher registrations with custom root type names

Closes gh-708

spring-graphql/src/main/java/org/springframework/graphql/execution/DefaultSchemaResourceGraphQlSourceBuilder.java

@@ -22,6 +22,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -30,6 +31,7 @@ import java.util.stream.Collectors;
 import graphql.GraphQL;
 import graphql.language.InterfaceTypeDefinition;
 import graphql.language.UnionTypeDefinition;
+import graphql.schema.DataFetcher;
 import graphql.schema.GraphQLSchema;
 import graphql.schema.TypeResolver;
 import graphql.schema.idl.CombinedWiringFactory;
@@ -45,6 +47,8 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 
 /**
@@ -149,6 +153,7 @@ final class DefaultSchemaResourceGraphQlSourceBuilder
 		}
 
 		RuntimeWiring runtimeWiring = initRuntimeWiring();
+		updateForCustomRootOperationTypeNames(registry, runtimeWiring);
 
 		TypeResolver typeResolver = initTypeResolver();
 		registry.types().values().forEach((def) -> {
@@ -210,6 +215,23 @@ final class DefaultSchemaResourceGraphQlSourceBuilder
 		return builder.build();
 	}
 
+	@SuppressWarnings("rawtypes")
+	private static void updateForCustomRootOperationTypeNames(
+			TypeDefinitionRegistry registry, RuntimeWiring runtimeWiring) {
+
+		if (registry.schemaDefinition().isEmpty()) {
+			return;
+		}
+
+		registry.schemaDefinition().get().getOperationTypeDefinitions().forEach((definition) -> {
+			String name = StringUtils.capitalize(definition.getName());
+			Map<String, DataFetcher> dataFetcherMap = runtimeWiring.getDataFetchers().remove(name);
+			if (!CollectionUtils.isEmpty(dataFetcherMap)) {
+				runtimeWiring.getDataFetchers().put(definition.getTypeName().getName(), dataFetcherMap);
+			}
+		});
+	}
+
 	private TypeResolver initTypeResolver() {
 		return (this.typeResolver != null) ? this.typeResolver : new ClassNameTypeResolver();
 	}

spring-graphql/src/test/java/org/springframework/graphql/execution/DefaultSchemaResourceGraphQlSourceBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 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.concurrent.atomic.AtomicInteger;
 import graphql.Scalars;
 import graphql.schema.DataFetcher;
 import graphql.schema.FieldCoordinates;
+import graphql.schema.GraphQLCodeRegistry;
 import graphql.schema.GraphQLFieldDefinition;
 import graphql.schema.GraphQLObjectType;
 import graphql.schema.GraphQLSchema;
@@ -78,13 +79,14 @@ public class DefaultSchemaResourceGraphQlSourceBuilderTests {
 	@Test
 	void typeVisitorToTransformSchema() {
 
-		String schemaContent = "" +
-				"type Query {" +
-				"  person: Person" +
-				"} " +
-				"type Person {" +
-				"  firstName: String" +
-				"}";
+		String schemaContent = """
+				type Query {
+					person: Person
+				}
+				type Person {
+					firstName: String
+				}
+				""";
 
 		GraphQLTypeVisitor visitor = new GraphQLTypeVisitorStub() {
 
@@ -113,6 +115,34 @@ public class DefaultSchemaResourceGraphQlSourceBuilderTests {
 		assertThat(schema.getObjectType("Person").getFieldDefinition("lastName")).isNotNull();
 	}
 
+	@Test // gh-708
+	void rootOperationTypesWithCustomNames() {
+		String schemaContent = """
+					schema {
+						query: MyQuery
+						mutation: MyMutation
+					}
+					type MyQuery {
+						hello: String!
+					}
+					type MyMutation {
+						saveGreeting(greeting: String!): String!
+					}
+				""";
+
+		GraphQLSchema schema = GraphQlSetup.schemaContent(schemaContent)
+				.runtimeWiring(wiringBuilder -> {
+					wiringBuilder.type("Query", builder -> builder.dataFetcher("hello", env -> ""));
+					wiringBuilder.type("Mutation", builder -> builder.dataFetcher("saveGreeting", env -> ""));
+				})
+				.toGraphQlSource()
+				.schema();
+
+		GraphQLCodeRegistry registry = schema.getCodeRegistry();
+		assertThat(registry.hasDataFetcher(FieldCoordinates.coordinates("MyQuery", "hello"))).isTrue();
+		assertThat(registry.hasDataFetcher(FieldCoordinates.coordinates("MyMutation", "saveGreeting"))).isTrue();
+	}
+
 	@Test
 	void wiringFactoryList() {