Configure support for GraphQL pagination and sorting

This commit auto-configures the new pagination and sorting support for
Spring for GraphQL, if Spring Data is available.
The `GraphQlAutoConfiguration` now contributes a `CursorStrategy` bean
that is used to set up the pagination and sorting data fetching
infrastructure.

This commit also configures by default a
`ConnectionTypeDefinitionConfigurer` that automatically detects
`*Connection` types and contributes the relevant schema definitions
according to the Relay spec.

See gh-34677

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/graphql/GraphQlAutoConfiguration.java

@@ -40,13 +40,22 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.convert.ApplicationConversionService;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.ResourcePatternResolver;
 import org.springframework.core.log.LogMessage;
+import org.springframework.data.domain.ScrollPosition;
 import org.springframework.graphql.ExecutionGraphQlService;
 import org.springframework.graphql.data.method.annotation.support.AnnotatedControllerConfigurer;
+import org.springframework.graphql.data.pagination.ConnectionFieldTypeVisitor;
+import org.springframework.graphql.data.pagination.CursorEncoder;
+import org.springframework.graphql.data.pagination.CursorStrategy;
+import org.springframework.graphql.data.query.ScrollPositionCursorStrategy;
+import org.springframework.graphql.data.query.SliceConnectionAdapter;
+import org.springframework.graphql.data.query.WindowConnectionAdapter;
 import org.springframework.graphql.execution.BatchLoaderRegistry;
+import org.springframework.graphql.execution.ConnectionTypeDefinitionConfigurer;
 import org.springframework.graphql.execution.DataFetcherExceptionResolver;
 import org.springframework.graphql.execution.DefaultBatchLoaderRegistry;
 import org.springframework.graphql.execution.DefaultExecutionGraphQlService;
@@ -94,6 +103,7 @@ public class GraphQlAutoConfiguration {
 		if (!properties.getSchema().getIntrospection().isEnabled()) {
 			builder.configureRuntimeWiring(this::enableIntrospection);
 		}
+		builder.configureTypeDefinitions(new ConnectionTypeDefinitionConfigurer());
 		wiringConfigurers.orderedStream().forEach(builder::configureRuntimeWiring);
 		sourceCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
 		return builder.build();
@@ -154,6 +164,32 @@ public class GraphQlAutoConfiguration {
 		return annotatedControllerConfigurer.getExceptionResolver();
 	}
 
+	@ConditionalOnClass(ScrollPosition.class)
+	@Configuration(proxyBeanMethods = false)
+	static class GraphQlDataAutoConfiguration {
+
+		@Bean
+		@ConditionalOnMissingBean
+		CursorStrategy<ScrollPosition> cursorStrategy() {
+			return CursorStrategy.withEncoder(new ScrollPositionCursorStrategy(), CursorEncoder.base64());
+		}
+
+		@Bean
+		@SuppressWarnings("unchecked")
+		GraphQlSourceBuilderCustomizer cursorStrategyCustomizer(CursorStrategy<?> cursorStrategy) {
+			if (cursorStrategy.supports(ScrollPosition.class)) {
+				CursorStrategy<ScrollPosition> scrollCursorStrategy = (CursorStrategy<ScrollPosition>) cursorStrategy;
+				ConnectionFieldTypeVisitor connectionFieldTypeVisitor = ConnectionFieldTypeVisitor
+					.create(List.of(new WindowConnectionAdapter(scrollCursorStrategy),
+							new SliceConnectionAdapter(scrollCursorStrategy)));
+				return (builder) -> builder.typeVisitors(List.of(connectionFieldTypeVisitor));
+			}
+			return (builder) -> {
+			};
+		}
+
+	}
+
 	static class GraphQlResourcesRuntimeHints implements RuntimeHintsRegistrar {
 
 		@Override

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/graphql/GraphQlAutoConfigurationTests.java

@@ -21,7 +21,12 @@ import java.nio.charset.StandardCharsets;
 import graphql.GraphQL;
 import graphql.execution.instrumentation.ChainedInstrumentation;
 import graphql.execution.instrumentation.Instrumentation;
+import graphql.schema.FieldCoordinates;
+import graphql.schema.GraphQLFieldDefinition;
+import graphql.schema.GraphQLObjectType;
+import graphql.schema.GraphQLOutputType;
 import graphql.schema.GraphQLSchema;
+import graphql.schema.PropertyDataFetcher;
 import graphql.schema.idl.RuntimeWiring;
 import graphql.schema.visibility.DefaultGraphqlFieldVisibility;
 import graphql.schema.visibility.NoIntrospectionGraphqlFieldVisibility;
@@ -39,6 +44,8 @@ import org.springframework.core.io.ByteArrayResource;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.graphql.ExecutionGraphQlService;
 import org.springframework.graphql.data.method.annotation.support.AnnotatedControllerConfigurer;
+import org.springframework.graphql.data.pagination.CursorStrategy;
+import org.springframework.graphql.data.pagination.EncodingCursorStrategy;
 import org.springframework.graphql.execution.BatchLoaderRegistry;
 import org.springframework.graphql.execution.DataFetcherExceptionResolver;
 import org.springframework.graphql.execution.DataLoaderRegistrar;
@@ -59,10 +66,12 @@ class GraphQlAutoConfigurationTests {
 	@Test
 	void shouldContributeDefaultBeans() {
 		this.contextRunner.run((context) -> {
-			assertThat(context).hasSingleBean(GraphQlSource.class);
-			assertThat(context).hasSingleBean(BatchLoaderRegistry.class);
-			assertThat(context).hasSingleBean(ExecutionGraphQlService.class);
-			assertThat(context).hasSingleBean(AnnotatedControllerConfigurer.class);
+			assertThat(context).hasSingleBean(GraphQlSource.class)
+				.hasSingleBean(BatchLoaderRegistry.class)
+				.hasSingleBean(ExecutionGraphQlService.class)
+				.hasSingleBean(AnnotatedControllerConfigurer.class)
+				.hasSingleBean(CursorStrategy.class);
+			assertThat(context.getBean(CursorStrategy.class)).isInstanceOf(EncodingCursorStrategy.class);
 		});
 	}
 
@@ -195,6 +204,29 @@ class GraphQlAutoConfigurationTests {
 		assertThat(RuntimeHintsPredicates.resource().forResource("graphql/other.graphqls")).accepts(hints);
 	}
 
+	@Test
+	void shouldContributeConnectionTypeDefinitionConfigurer() {
+		this.contextRunner.withUserConfiguration(CustomGraphQlBuilderConfiguration.class).run((context) -> {
+			GraphQlSource graphQlSource = context.getBean(GraphQlSource.class);
+			GraphQLSchema schema = graphQlSource.schema();
+			GraphQLOutputType bookConnection = schema.getQueryType().getField("books").getType();
+			assertThat(bookConnection).isNotNull().isInstanceOf(GraphQLObjectType.class);
+			assertThat((GraphQLObjectType) bookConnection)
+				.satisfies((connection) -> assertThat(connection.getFieldDefinition("edges")).isNotNull());
+		});
+	}
+
+	@Test
+	void shouldContributeConnectionDataFetcher() {
+		this.contextRunner.withUserConfiguration(CustomGraphQlBuilderConfiguration.class).run((context) -> {
+			GraphQlSource graphQlSource = context.getBean(GraphQlSource.class);
+			GraphQLFieldDefinition books = graphQlSource.schema().getQueryType().getField("books");
+			FieldCoordinates booksCoordinates = FieldCoordinates.coordinates("Query", "books");
+			assertThat(graphQlSource.schema().getCodeRegistry().getDataFetcher(booksCoordinates, books))
+				.isNotInstanceOf(PropertyDataFetcher.class);
+		});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class CustomGraphQlBuilderConfiguration {
 

spring-boot-project/spring-boot-autoconfigure/src/test/resources/graphql/schema.graphqls

@@ -1,4 +1,5 @@
 type Query {
     greeting(name: String! = "Spring"): String!
     bookById(id: ID): Book
+    books: BookConnection
 }