Add support for using WebFlux's WebTestClient to document an API

Closes gh-384

docs/src/test/java/com/example/webtestclient/RequestPartPayload.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2014-2017 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
+ *
+ *      http://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 com.example.webtestclient;
+
+import java.util.Collections;
+
+import org.springframework.core.io.ByteArrayResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+
+import static org.springframework.restdocs.payload.PayloadDocumentation.fieldWithPath;
+import static org.springframework.restdocs.payload.PayloadDocumentation.requestPartBody;
+import static org.springframework.restdocs.payload.PayloadDocumentation.requestPartFields;
+import static org.springframework.restdocs.webtestclient.WebTestClientRestDocumentation.document;
+
+public class RequestPartPayload {
+
+	// @formatter:off
+
+	private WebTestClient webTestClient;
+
+	public void fields() throws Exception {
+		// tag::fields[]
+		MultiValueMap<String, Object> multipartData = new LinkedMultiValueMap<>();
+		Resource imageResource = new ByteArrayResource("<<png data>>".getBytes()) {
+
+			@Override
+			public String getFilename() {
+				return "image.png";
+			}
+
+		};
+		multipartData.add("image", imageResource);
+		multipartData.add("metadata", Collections.singletonMap("version",  "1.0"));
+		this.webTestClient.post().uri("/images").syncBody(multipartData)
+			.accept(MediaType.APPLICATION_JSON).exchange()
+			.expectStatus().isOk().expectBody()
+			.consumeWith(document("image-upload",
+				requestPartFields("metadata", // <1>
+					fieldWithPath("version").description("The version of the image")))); // <2>
+		// end::fields[]
+	}
+
+	public void body() throws Exception {
+		// tag::body[]
+		MultiValueMap<String, Object> multipartData = new LinkedMultiValueMap<>();
+		Resource imageResource = new ByteArrayResource("<<png data>>".getBytes()) {
+
+			@Override
+			public String getFilename() {
+				return "image.png";
+			}
+
+		};
+		multipartData.add("image", imageResource);
+		multipartData.add("metadata", Collections.singletonMap("version",  "1.0"));
+
+		this.webTestClient.post().uri("/images").syncBody(multipartData)
+			.accept(MediaType.APPLICATION_JSON).exchange()
+			.expectStatus().isOk().expectBody()
+			.consumeWith(document("image-upload",
+					requestPartBody("metadata"))); // <1>
+		// end::body[]
+	}
+
+}