"sharedHttpSession" shortcut for MockMvc builders

Issue: SPR-13820

spring-test/src/main/java/org/springframework/test/web/servlet/setup/ConfigurableMockMvcBuilder.java

@@ -122,6 +122,13 @@ public interface ConfigurableMockMvcBuilder<B extends ConfigurableMockMvcBuilder
 	/**
 	 * Add a {@code MockMvcConfigurer} that automates MockMvc setup and
 	 * configures it for some specific purpose (e.g. security).
+	 *
+	 * <p>There is a built-in {@link SharedHttpSessionConfigurer} that can be
+	 * used to re-use the HTTP session across requests. 3rd party frameworks
+	 * like Spring Security also use this mechanism to provide configuration
+	 * shortcuts.
+	 *
+	 * @see SharedHttpSessionConfigurer
 	 */
 	<T extends B> T apply(MockMvcConfigurer configurer);
 

spring-test/src/main/java/org/springframework/test/web/servlet/setup/SharedHttpSessionConfigurer.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2002-2017 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 org.springframework.test.web.servlet.setup;
+
+import javax.servlet.http.HttpSession;
+
+import org.springframework.test.web.servlet.request.RequestPostProcessor;
+import org.springframework.web.context.WebApplicationContext;
+
+/**
+ * {@link MockMvcConfigurer} that stores and re-uses the HTTP session across
+ * multiple requests performed through the same {@code MockMvc} instance.
+ *
+ * <p>Example use:
+ * <pre class="code">
+ * import static org.springframework.test.web.servlet.setup.SharedHttpSessionConfigurer.sharedHttpSession;
+ *
+ * // ...
+ *
+ * MockMvc mockMvc = MockMvcBuilders.standaloneSetup(new TestController())
+ *         .apply(sharedHttpSession())
+ *         .build();
+ *
+ * // Use mockMvc to perform requests ...
+ * </pre>
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.0
+ */
+public class SharedHttpSessionConfigurer implements MockMvcConfigurer {
+
+	private HttpSession session;
+
+
+	@Override
+	public void afterConfigurerAdded(ConfigurableMockMvcBuilder<?> builder) {
+		builder.alwaysDo(result -> this.session = result.getRequest().getSession(false));
+	}
+
+	@Override
+	public RequestPostProcessor beforeMockMvcCreated(ConfigurableMockMvcBuilder<?> builder,
+			WebApplicationContext context) {
+
+		return request -> {
+			if (this.session != null) {
+				request.setSession(this.session);
+			}
+			return request;
+		};
+	}
+
+	public static SharedHttpSessionConfigurer sharedHttpSession() {
+		return new SharedHttpSessionConfigurer();
+	}
+
+}