Add ConnectionTypeConfigurer

See gh-620

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

@@ -17,7 +17,6 @@ package org.springframework.graphql.execution;
 
 import java.util.LinkedHashSet;
 import java.util.Set;
-import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import graphql.language.FieldDefinition;
@@ -30,18 +29,20 @@ import graphql.language.TypeName;
 import graphql.schema.idl.TypeDefinitionRegistry;
 
 /**
- * Exposes the {@link #generateConnectionTypes(TypeDefinitionRegistry)
- * generateConnectionTypes method} for adding boilerplate type definitions to a
- * {@link TypeDefinitionRegistry}, for pagination based on the Relay
- * <a href="https://relay.dev/graphql/connections.htm">GraphQL Cursor Connections Specification</a>.
+ * {@link TypeDefinitionConfigurer} that generates "Connection" types by looking
+ * for fields whose type definition name ends in "Connection", considered by the
+ * <a href="https://relay.dev/graphql/connections.htm">GraphQL Cursor Connections Specification</a>
+ * to be a {@literal Connection Type}, and adding the required type definitions
+ * if they don't already exist.
  *
- * <p>Use {@link GraphQlSource.SchemaResourceBuilder#configureTypeDefinitionRegistry(Function)}
- * to enable connection type generation.
+ * <p>This is intended to be set on
+ * {@link GraphQlSource.SchemaResourceBuilder#configureTypeDefinitions(TypeDefinitionConfigurer)
+ * GraphQlSource.Builder}.
  *
  * @author Rossen Stoyanchev
  * @since 1.2
  */
-public class ConnectionTypeGenerator {
+public class ConnectionTypeDefinitionConfigurer implements TypeDefinitionConfigurer {
 
 	private static final TypeName STRING_TYPE = new TypeName("String");
 
@@ -50,14 +51,8 @@ public class ConnectionTypeGenerator {
 	private static final TypeName PAGE_INFO_TYPE = new TypeName("PageInfo");
 
 
-	/**
-	 * Find fields whose type definition name ends in "Connection", considered
-	 * by the spec to be a {@literal Connection Type}, and add type definitions
-	 * for all such types, if they don't exist already.
-	 * @param registry the registry to check and add types to
-	 * @return the same registry instance with additional types added
-	 */
-	public TypeDefinitionRegistry generateConnectionTypes(TypeDefinitionRegistry registry) {
+	@Override
+	public void configure(TypeDefinitionRegistry registry) {
 
 		Set<String> typeNames = findConnectionTypeNames(registry);
 
@@ -89,8 +84,6 @@ public class ConnectionTypeGenerator {
 						.build());
 			});
 		}
-
-		return registry;
 	}
 
 	private static Set<String> findConnectionTypeNames(TypeDefinitionRegistry registry) {

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

@@ -24,7 +24,6 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.function.BiFunction;
-import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import graphql.language.InterfaceTypeDefinition;
@@ -61,8 +60,7 @@ final class DefaultSchemaResourceGraphQlSourceBuilder
 
 	private final Set<Resource> schemaResources = new LinkedHashSet<>();
 
-	@Nullable
-	private Function<TypeDefinitionRegistry, TypeDefinitionRegistry> typeDefinitionRegistryConfigurer;
+	private List<TypeDefinitionConfigurer> typeDefinitionConfigurers = new ArrayList<>();
 
 	private final List<RuntimeWiringConfigurer> runtimeWiringConfigurers = new ArrayList<>();
 
@@ -81,12 +79,8 @@ final class DefaultSchemaResourceGraphQlSourceBuilder
 	}
 
 	@Override
-	public GraphQlSource.SchemaResourceBuilder configureTypeDefinitionRegistry(
-			Function<TypeDefinitionRegistry, TypeDefinitionRegistry> configurer) {
-
-		this.typeDefinitionRegistryConfigurer = (this.typeDefinitionRegistryConfigurer != null ?
-				this.typeDefinitionRegistryConfigurer.andThen(configurer) : configurer);
-
+	public GraphQlSource.SchemaResourceBuilder configureTypeDefinitions(TypeDefinitionConfigurer configurer) {
+		this.typeDefinitionConfigurers.add(configurer);
 		return this;
 	}
 
@@ -118,8 +112,8 @@ final class DefaultSchemaResourceGraphQlSourceBuilder
 				.reduce(TypeDefinitionRegistry::merge)
 				.orElseThrow(MissingSchemaException::new);
 
-		if (this.typeDefinitionRegistryConfigurer != null) {
-			registry = this.typeDefinitionRegistryConfigurer.apply(registry);
+		for (TypeDefinitionConfigurer configurer : this.typeDefinitionConfigurers) {
+			configurer.configure(registry);
 		}
 
 		logger.info("Loaded " + this.schemaResources.size() + " resource(s) in the GraphQL schema.");

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

@@ -173,17 +173,14 @@ public interface GraphQlSource {
 		SchemaResourceBuilder schemaResources(Resource... resources);
 
 		/**
-		 * Provide a function to customize the {@link TypeDefinitionRegistry}
-		 * created by parsing schema files. This allows adding or changing schema
-		 * type definitions before {@link GraphQLSchema} is created and validated.
-		 * @param configurer the function to apply accepting the current
-		 * {@link TypeDefinitionRegistry} and returning the one to use, likely
-		 * the same instance since {@link TypeDefinitionRegistry} is mutable.
+		 * Customize the {@link TypeDefinitionRegistry} created from parsed
+		 * schema files, adding or changing schema type definitions before the
+		 * {@link GraphQLSchema} is created and validated.
+		 * @param configurer the configurer to apply
 		 * @return the current builder
-		 * @sine 1.2
+		 * @since 1.2
 		 */
-		SchemaResourceBuilder configureTypeDefinitionRegistry(
-				Function<TypeDefinitionRegistry, TypeDefinitionRegistry> configurer);
+		SchemaResourceBuilder configureTypeDefinitions(TypeDefinitionConfigurer configurer);
 
 		/**
 		 * Configure the underlying {@link RuntimeWiring.Builder} to register

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

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2002-2023 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.graphql.execution;
+
+import graphql.schema.GraphQLSchema;
+import graphql.schema.idl.TypeDefinitionRegistry;
+
+/**
+ * Callback that allows customizing the {@link TypeDefinitionRegistry} created
+ * from parsed schema files. It allows adding schema types programmatically
+ * before the registry is used to create {@link GraphQLSchema}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 1.2
+ */
+public interface TypeDefinitionConfigurer {
+
+	/**
+	 * Customize the given {@link TypeDefinitionRegistry}.
+	 * @param registry the registry to customize
+	 */
+	void configure(TypeDefinitionRegistry registry);
+
+}

spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/SchemaMappingPaginationTests.java

@@ -35,7 +35,7 @@ import org.springframework.graphql.data.pagination.ConnectionFieldTypeVisitor;
 import org.springframework.graphql.data.query.ScrollPositionCursorStrategy;
 import org.springframework.graphql.data.query.ScrollSubrange;
 import org.springframework.graphql.data.query.WindowConnectionAdapter;
-import org.springframework.graphql.execution.ConnectionTypeGenerator;
+import org.springframework.graphql.execution.ConnectionTypeDefinitionConfigurer;
 import org.springframework.stereotype.Controller;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -83,8 +83,7 @@ public class SchemaMappingPaginationTests {
 
 		ExecutionGraphQlService graphQlService = graphQlService((configurer, setup) -> {
 
-			ConnectionTypeGenerator typeGenerator = new ConnectionTypeGenerator();
-			setup.typeDefinitionRegistryConfigurer(typeGenerator::generateConnectionTypes);
+			setup.typeDefinitionConfigurer(new ConnectionTypeDefinitionConfigurer());
 
 			ScrollPositionCursorStrategy cursorStrategy = new ScrollPositionCursorStrategy();
 			WindowConnectionAdapter connectionAdapter = new WindowConnectionAdapter(cursorStrategy);

spring-graphql/src/test/java/org/springframework/graphql/data/pagination/ConnectionFieldTypeVisitorTests.java

@@ -26,7 +26,7 @@ import org.springframework.graphql.BookSource;
 import org.springframework.graphql.ExecutionGraphQlResponse;
 import org.springframework.graphql.GraphQlSetup;
 import org.springframework.graphql.TestExecutionRequest;
-import org.springframework.graphql.execution.ConnectionTypeGenerator;
+import org.springframework.graphql.execution.ConnectionTypeDefinitionConfigurer;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -75,7 +75,7 @@ public class ConnectionFieldTypeVisitorTests {
 
 		ExecutionGraphQlResponse response = GraphQlSetup.schemaContent(schemaContent)
 				.dataFetcher("Query", "books", env -> BookSource.books())
-				.typeDefinitionRegistryConfigurer(new ConnectionTypeGenerator()::generateConnectionTypes)
+				.typeDefinitionConfigurer(new ConnectionTypeDefinitionConfigurer())
 				.typeVisitor(ConnectionFieldTypeVisitor.create(List.of(adapter)))
 				.toGraphQlService()
 				.execute(TestExecutionRequest.forDocument(document))

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

@@ -38,12 +38,12 @@ import org.springframework.graphql.TestExecutionRequest;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Unit tests for {@link ConnectionTypeGenerator}.
+ * Unit tests for {@link ConnectionTypeDefinitionConfigurer}.
  *
  * @author Rossen Stoyanchev
  * @since 1.2
  */
-public class ConnectionTypeGeneratorTests {
+public class ConnectionTypeDefinitionConfigurerTests {
 
 	@Test
 	void connectionTypeGeneration() throws Exception {
@@ -108,8 +108,7 @@ public class ConnectionTypeGeneratorTests {
 	}
 
 	private GraphQlSetup initGraphQlSetup(String schema) {
-		ConnectionTypeGenerator generator = new ConnectionTypeGenerator();
-		return GraphQlSetup.schemaContent(schema).typeDefinitionRegistryConfigurer(generator::generateConnectionTypes);
+		return GraphQlSetup.schemaContent(schema).typeDefinitionConfigurer(new ConnectionTypeDefinitionConfigurer());
 	}
 
 	private static <N> Connection<N> createConnection(

spring-graphql/src/testFixtures/java/org/springframework/graphql/GraphQlSetup.java

@@ -19,14 +19,12 @@ import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.function.Function;
 
 import graphql.GraphQL;
 import graphql.execution.instrumentation.Instrumentation;
 import graphql.schema.DataFetcher;
 import graphql.schema.GraphQLTypeVisitor;
 import graphql.schema.TypeResolver;
-import graphql.schema.idl.TypeDefinitionRegistry;
 
 import org.springframework.context.ApplicationContext;
 import org.springframework.core.io.ByteArrayResource;
@@ -38,6 +36,7 @@ import org.springframework.graphql.execution.DefaultExecutionGraphQlService;
 import org.springframework.graphql.execution.GraphQlSource;
 import org.springframework.graphql.execution.RuntimeWiringConfigurer;
 import org.springframework.graphql.execution.SubscriptionExceptionResolver;
+import org.springframework.graphql.execution.TypeDefinitionConfigurer;
 import org.springframework.graphql.server.WebGraphQlHandler;
 import org.springframework.graphql.server.WebGraphQlInterceptor;
 import org.springframework.graphql.server.WebGraphQlSetup;
@@ -82,10 +81,8 @@ public class GraphQlSetup implements GraphQlServiceSetup {
 				wiringBuilder.type(type, typeBuilder -> typeBuilder.dataFetcher(field, dataFetcher)));
 	}
 
-	public GraphQlSetup typeDefinitionRegistryConfigurer(
-			Function<TypeDefinitionRegistry, TypeDefinitionRegistry> configurer) {
-
-		this.graphQlSourceBuilder.configureTypeDefinitionRegistry(configurer);
+	public GraphQlSetup typeDefinitionConfigurer(TypeDefinitionConfigurer configurer) {
+		this.graphQlSourceBuilder.configureTypeDefinitions(configurer);
 		return this;
 	}