#1225 - Provide implementation of WebTestClientConfigurer to support hypermedia registration.

Expand reference documentation to show ways to use it directly or via Spring Boot.

src/main/java/org/springframework/hateoas/config/HypermediaWebTestClientConfigurer.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2019-2020 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.hateoas.config;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.http.client.reactive.ClientHttpConnector;
+import org.springframework.http.codec.ClientCodecConfigurer;
+import org.springframework.http.codec.json.Jackson2JsonDecoder;
+import org.springframework.http.codec.json.Jackson2JsonEncoder;
+import org.springframework.test.web.reactive.server.MockServerConfigurer;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.test.web.reactive.server.WebTestClientConfigurer;
+import org.springframework.util.Assert;
+import org.springframework.util.MimeType;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+import java.util.List;
+import java.util.function.Consumer;
+
+/**
+ * Assembles {@link Jackson2JsonEncoder}s and {@link Jackson2JsonDecoder}s needed to wire a {@link WebTestClient} with
+ * hypermedia support.
+ *
+ * @author Greg Turnquist
+ * @since 1.1
+ */
+public class HypermediaWebTestClientConfigurer implements WebTestClientConfigurer, MockServerConfigurer {
+
+	private Consumer<ClientCodecConfigurer> configurer;
+
+	/**
+	 * Creates a new {@link HypermediaWebTestClientConfigurer} for the given {@link ObjectMapper} and
+	 * {@link HypermediaMappingInformation}s.
+	 *
+	 * @param mapper must not be {@literal null}.
+	 * @param hypermediaTypes must not be {@literal null}.
+	 */
+	HypermediaWebTestClientConfigurer(ObjectMapper mapper, List<HypermediaMappingInformation> hypermediaTypes) {
+
+		Assert.notNull(mapper, "mapper must not be null!");
+		Assert.notNull(hypermediaTypes, "hypermediaTypes must not be null!");
+
+		this.configurer = clientCodecConfigurer -> hypermediaTypes.forEach(hypermediaType -> {
+
+			ObjectMapper objectMapper = hypermediaType.configureObjectMapper(mapper.copy());
+			MimeType[] mimeTypes = hypermediaType.getMediaTypes().toArray(new MimeType[0]);
+
+			clientCodecConfigurer.customCodecs().registerWithDefaultConfig(new Jackson2JsonEncoder(objectMapper, mimeTypes));
+			clientCodecConfigurer.customCodecs().registerWithDefaultConfig(new Jackson2JsonDecoder(objectMapper, mimeTypes));
+		});
+	}
+
+	/**
+	 * Register the proper {@link Jackson2JsonEncoder}s and {@link Jackson2JsonDecoder}s for a given
+	 * {@link WebTestClient}.
+	 */
+	@Override
+	public void afterConfigurerAdded(WebTestClient.Builder builder, WebHttpHandlerBuilder webHttpHandlerBuilder,
+			ClientHttpConnector clientHttpConnector) {
+		builder.codecs(this.configurer);
+	}
+}

src/main/java/org/springframework/hateoas/config/WebClientHateoasConfiguration.java

@@ -15,19 +15,18 @@
  */
 package org.springframework.hateoas.config;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.RequiredArgsConstructor;
-
-import java.util.List;
-
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.lang.NonNull;
 import org.springframework.web.reactive.function.client.WebClient;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
+import java.util.List;
 
 /**
  * Spring WebFlux HATEOAS configuration.
@@ -44,6 +43,13 @@ class WebClientHateoasConfiguration {
 		return new WebClientConfigurer(mapper.getIfAvailable(ObjectMapper::new), hypermediaTypes);
 	}
 
+	@Bean
+	@Lazy
+    HypermediaWebTestClientConfigurer webTestClientConfigurer(ObjectProvider<ObjectMapper> mapper,
+                                                              List<HypermediaMappingInformation> hypermediaTypes) {
+		return new HypermediaWebTestClientConfigurer(mapper.getIfAvailable(ObjectMapper::new), hypermediaTypes);
+	}
+
 	@Bean
 	static HypermediaWebClientBeanPostProcessor webClientBeanPostProcessor(
 			ObjectProvider<WebClientConfigurer> configurer) {