Configure interceptors on WebSocketGraphQlTester

This commit adds two new methods on the `WebSocketGraphQlTester` builder
to configure `GraphQlClientInterceptor` instances on the client.
For now, this is only accessible on the WebSocket tester but could be
promoted to a higher level builder in the future.

Closes gh-823

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultWebSocketGraphQlTesterBuilder.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.
@@ -18,10 +18,14 @@ package org.springframework.graphql.test.tester;
 
 
 import java.net.URI;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 import java.util.function.Consumer;
 
 import reactor.core.publisher.Mono;
 
+import org.springframework.graphql.client.GraphQlClientInterceptor;
 import org.springframework.graphql.client.WebSocketGraphQlClient;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.codec.CodecConfigurer;
@@ -41,6 +45,8 @@ final class DefaultWebSocketGraphQlTesterBuilder
 
 	private final WebSocketGraphQlClient.Builder<?> graphQlClientBuilder;
 
+	private final List<GraphQlClientInterceptor> interceptors = new ArrayList<>();
+
 
 	/**
 	 * Constructor to start via {@link WebSocketGraphQlTester#builder(String, WebSocketClient)}.
@@ -98,10 +104,22 @@ final class DefaultWebSocketGraphQlTesterBuilder
 		return this;
 	}
 
+	@Override
+	public DefaultWebSocketGraphQlTesterBuilder interceptor(GraphQlClientInterceptor... interceptors) {
+		this.interceptors.addAll(Arrays.asList(interceptors));
+		return this;
+	}
+
+	@Override
+	public DefaultWebSocketGraphQlTesterBuilder interceptors(Consumer<List<GraphQlClientInterceptor>> interceptorsConsumer) {
+		interceptorsConsumer.accept(this.interceptors);
+		return this;
+	}
+
 	@Override
 	public WebSocketGraphQlTester build() {
 		registerJsonPathMappingProvider();
-		WebSocketGraphQlClient client = this.graphQlClientBuilder.build();
+		WebSocketGraphQlClient client = this.graphQlClientBuilder.interceptors((list) -> list.addAll(this.interceptors)).build();
 		GraphQlTester graphQlTester = super.buildGraphQlTester(asTransport(client));
 		return new DefaultWebSocketGraphQlTester(graphQlTester, client, getBuilderInitializer());
 	}

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

@@ -17,9 +17,13 @@
 package org.springframework.graphql.test.tester;
 
 import java.net.URI;
+import java.util.List;
+import java.util.function.Consumer;
 
 import reactor.core.publisher.Mono;
 
+import org.springframework.graphql.client.GraphQlClientInterceptor;
+import org.springframework.graphql.client.GraphQlTransport;
 import org.springframework.graphql.client.WebSocketGraphQlClient;
 import org.springframework.web.reactive.socket.client.WebSocketClient;
 
@@ -81,6 +85,22 @@ public interface WebSocketGraphQlTester extends WebGraphQlTester {
 	 */
 	interface Builder<B extends Builder<B>> extends WebGraphQlTester.Builder<B> {
 
+		/**
+		 * Configure interceptors to be invoked before delegating to the
+		 * {@link GraphQlTransport} to perform the request.
+		 * @param interceptors the interceptors to add
+		 * @return this builder
+		 */
+		B interceptor(GraphQlClientInterceptor... interceptors);
+
+		/**
+		 * Customize the list of interceptors. The provided list is "live", so
+		 * the consumer can inspect and insert interceptors accordingly.
+		 * @param interceptorsConsumer consumer to customize the interceptors with
+		 * @return this builder
+		 */
+		B interceptors(Consumer<List<GraphQlClientInterceptor>> interceptorsConsumer);
+
 		/**
 		 * Build the {@code WebSocketGraphQlTester}.
 		 */

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

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2020-2024 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.
+ * 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.test.tester;
+
+import java.net.URI;
+import java.time.Duration;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+
+import org.springframework.graphql.client.ClientGraphQlRequest;
+import org.springframework.graphql.client.ClientGraphQlResponse;
+import org.springframework.graphql.client.GraphQlClientInterceptor;
+import org.springframework.graphql.client.TestWebSocketClient;
+import org.springframework.graphql.client.WebSocketGraphQlClient;
+import org.springframework.graphql.execution.MockExecutionGraphQlService;
+import org.springframework.graphql.server.WebGraphQlHandler;
+import org.springframework.graphql.server.webflux.GraphQlWebSocketHandler;
+import org.springframework.http.codec.ClientCodecConfigurer;
+import org.springframework.web.reactive.socket.WebSocketHandler;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link WebSocketGraphQlTester}.
+ */
+class WebSocketGraphQlTesterTests {
+
+
+	@Test
+	void shouldConfigureInterceptors() {
+		TestInterceptor testInterceptor = new TestInterceptor();
+		TestWebSocketClient webSocketClient = createWebSocketClient();
+		WebSocketGraphQlClient client = WebSocketGraphQlClient.builder(URI.create(""), webSocketClient)
+				.interceptor(testInterceptor)
+				.build();
+
+		client.document("{ Query }").execute().block(Duration.ofMillis(500));
+		assertThat(testInterceptor.executed).as("Interceptor is not executed").isTrue();
+	}
+
+	private TestWebSocketClient createWebSocketClient() {
+		MockExecutionGraphQlService graphQlService = new MockExecutionGraphQlService();
+		graphQlService.setDefaultResponse("{}");
+		WebGraphQlHandler graphQlHandler = WebGraphQlHandler.builder(graphQlService).build();
+		ClientCodecConfigurer configurer = ClientCodecConfigurer.create();
+		WebSocketHandler handler = new GraphQlWebSocketHandler(graphQlHandler, configurer, Duration.ofSeconds(5));
+		return new TestWebSocketClient(handler);
+	}
+
+	class TestInterceptor implements GraphQlClientInterceptor {
+
+		AtomicBoolean executed = new AtomicBoolean();
+
+		@Override
+		public Mono<ClientGraphQlResponse> intercept(ClientGraphQlRequest request, Chain chain) {
+			return chain.next(request).doOnNext((response) -> executed.set(true));
+		}
+	}
+
+}