JSON config in ExecutionGraphQlServiceTester builder

See gh-345

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultExecutionGraphQlServiceTesterBuilder.java

@@ -17,9 +17,13 @@
 package org.springframework.graphql.test.tester;
 
 
+import java.util.Collections;
 import java.util.function.Consumer;
 
+import org.springframework.core.codec.Decoder;
+import org.springframework.core.codec.Encoder;
 import org.springframework.graphql.ExecutionGraphQlService;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 
@@ -36,6 +40,12 @@ final class DefaultExecutionGraphQlServiceTesterBuilder
 
 	private final ExecutionGraphQlService service;
 
+	@Nullable
+	private Encoder<?> encoder;
+
+	@Nullable
+	private Decoder<?> decoder;
+
 
 	DefaultExecutionGraphQlServiceTesterBuilder(ExecutionGraphQlService service) {
 		Assert.notNull(service, "GraphQlService is required");
@@ -46,14 +56,36 @@ final class DefaultExecutionGraphQlServiceTesterBuilder
 		this.service = transport.getGraphQlService();
 	}
 
+	@Override
+	public DefaultExecutionGraphQlServiceTesterBuilder encoder(Encoder<?> encoder) {
+		this.encoder = encoder;
+		return this;
+	}
+
+	@Override
+	public DefaultExecutionGraphQlServiceTesterBuilder decoder(Decoder<?> decoder) {
+		this.decoder = decoder;
+		return this;
+	}
 
 	@Override
 	public ExecutionGraphQlServiceTester build() {
+		registerJsonPathMappingProvider();
 		GraphQlServiceGraphQlTransport transport = new GraphQlServiceGraphQlTransport(this.service);
 		GraphQlTester tester = super.buildGraphQlTester(transport);
 		return new DefaultExecutionGraphQlServiceTester(tester, transport, getBuilderInitializer());
 	}
 
+	private void registerJsonPathMappingProvider() {
+		if (this.encoder != null && this.decoder != null) {
+			configureJsonPathConfig(config -> {
+				EncoderDecoderMappingProvider provider = new EncoderDecoderMappingProvider(
+						Collections.singletonList(this.encoder), Collections.singletonList(this.decoder));
+				return config.mappingProvider(provider);
+			});
+		}
+	}
+
 
 	/**
 	 * Default {@link ExecutionGraphQlServiceTester} implementation.

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/ExecutionGraphQlServiceTester.java

@@ -16,6 +16,8 @@
 
 package org.springframework.graphql.test.tester;
 
+import org.springframework.core.codec.Decoder;
+import org.springframework.core.codec.Encoder;
 import org.springframework.graphql.ExecutionGraphQlService;
 
 /**
@@ -52,6 +54,18 @@ public interface ExecutionGraphQlServiceTester extends GraphQlTester {
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlTester.Builder<B> {
 
+		/**
+		 * Configure the JSON encoder to use for mapping response data to
+		 * higher level objects.
+		 */
+		B encoder(Encoder<?> encoder);
+
+		/**
+		 * Configure the JSON decoder to use for mapping response data to
+		 * higher level objects.
+		 */
+		B decoder(Decoder<?> decoder);
+
 		/**
 		 * Build a {@link ExecutionGraphQlServiceTester} instance.
 		 */

spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterBuilderTests.java

@@ -16,12 +16,23 @@
 
 package org.springframework.graphql.test.tester;
 
+import java.util.Collections;
+import java.util.Map;
+
+import graphql.ExecutionResultImpl;
 import graphql.GraphqlErrorBuilder;
 import org.junit.jupiter.api.Test;
 import reactor.core.publisher.Mono;
 
+import org.springframework.core.ResolvableType;
+import org.springframework.core.codec.DecodingException;
+import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.graphql.ExecutionGraphQlService;
 import org.springframework.graphql.support.DocumentSource;
+import org.springframework.http.codec.json.Jackson2JsonDecoder;
+import org.springframework.http.codec.json.Jackson2JsonEncoder;
+import org.springframework.lang.Nullable;
+import org.springframework.util.MimeType;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -65,6 +76,34 @@ public class GraphQlTesterBuilderTests extends GraphQlTesterTestSupport {
 		assertThat(getActualRequestDocument()).isEqualTo(DOCUMENT);
 	}
 
+	@Test
+	void codecConfigurerRegistersJsonPathMappingProvider() {
+
+		TestJackson2JsonDecoder testDecoder = new TestJackson2JsonDecoder();
+
+		ExecutionGraphQlServiceTester.Builder<?> builder = graphQlTesterBuilder()
+				.encoder(new Jackson2JsonEncoder())
+				.decoder(testDecoder);
+
+		String document = "{me {name}}";
+		MovieCharacter character = MovieCharacter.create("Luke Skywalker");
+		getGraphQlService().setResponse(document,
+				ExecutionResultImpl.newExecutionResult()
+						.data(Collections.singletonMap("me", character))
+						.build());
+
+		GraphQlTester client = builder.build();
+		GraphQlTester.Response response = client.document(document).execute();
+
+		testDecoder.resetLastValue();
+		assertThat(testDecoder.getLastValue()).isNull();
+
+		assertThat(response).isNotNull();
+		response.path("me").entity(MovieCharacter.class).isEqualTo(character);
+		response.path("me").matchesJson("{name:\"Luke Skywalker\"}");
+		assertThat(testDecoder.getLastValue()).isEqualTo(character);
+	}
+
 	@Test
 	void errorsFilteredGlobally() {
 
@@ -86,4 +125,29 @@ public class GraphQlTesterBuilderTests extends GraphQlTesterTestSupport {
 		assertThat(getActualRequestDocument()).contains(document);
 	}
 
+
+	private static class TestJackson2JsonDecoder extends Jackson2JsonDecoder {
+
+		@Nullable
+		private Object lastValue;
+
+		@Nullable
+		Object getLastValue() {
+			return this.lastValue;
+		}
+
+		@Override
+		public Object decode(DataBuffer dataBuffer, ResolvableType targetType,
+				@Nullable MimeType mimeType, @Nullable Map<String, Object> hints) throws DecodingException {
+
+			this.lastValue = super.decode(dataBuffer, targetType, mimeType, hints);
+			return this.lastValue;
+		}
+
+		void resetLastValue() {
+			this.lastValue = null;
+		}
+
+	}
+
 }

spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTestSupport.java

@@ -28,7 +28,8 @@ public class GraphQlTesterTestSupport {
 
 	private final MockExecutionGraphQlService graphQlService = new MockExecutionGraphQlService();
 
-	private final GraphQlTester.Builder<?> graphQlTesterBuilder = ExecutionGraphQlServiceTester.builder(this.graphQlService);
+	private final ExecutionGraphQlServiceTester.Builder<?> graphQlTesterBuilder =
+			ExecutionGraphQlServiceTester.builder(this.graphQlService);
 
 	private final GraphQlTester graphQlTester = this.graphQlTesterBuilder.build();
 
@@ -45,7 +46,7 @@ public class GraphQlTesterTestSupport {
 		return this.graphQlTester;
 	}
 
-	public GraphQlTester.Builder<?> graphQlTesterBuilder() {
+	public ExecutionGraphQlServiceTester.Builder<?> graphQlTesterBuilder() {
 		return this.graphQlTesterBuilder;
 	}