Add extension point to pre-configure a MockMvcBuilder

Issue: SPR-11497

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

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -50,6 +50,8 @@ public abstract class AbstractMockMvcBuilder<B extends AbstractMockMvcBuilder<B>
 
 	private Boolean dispatchOptions = Boolean.FALSE;
 
+	private final List<MockMvcConfigurer> configurers = new ArrayList<MockMvcConfigurer>(4);
+
 
 
 	/**
@@ -166,9 +168,9 @@ public abstract class AbstractMockMvcBuilder<B extends AbstractMockMvcBuilder<B>
 	}
 
 	/**
-	 * Should the {@link org.springframework.web.servlet.DispatcherServlet} dispatch OPTIONS request to controllers.
-	 * @param dispatchOptions
-	 * @see org.springframework.web.servlet.DispatcherServlet#setDispatchOptionsRequest(boolean)
+	 * Whether to enable the DispatcherServlet property
+	 * {@link org.springframework.web.servlet.DispatcherServlet#setDispatchOptionsRequest
+	 * dispatchOptionsRequest} which allows processing of HTTP OPTIONS requests.
 	 */
 	@SuppressWarnings("unchecked")
 	public final <T extends B> T dispatchOptions(boolean dispatchOptions) {
@@ -176,6 +178,18 @@ public abstract class AbstractMockMvcBuilder<B extends AbstractMockMvcBuilder<B>
 		return (T) this;
 	}
 
+	/**
+	 * Add a {@code MockMvcConfigurer} which encapsulates ways to further configure
+	 * this MockMvcBuilder with some specific purpose in mind.
+	 */
+	@SuppressWarnings("unchecked")
+	public final <T extends B> T add(MockMvcConfigurer configurer) {
+		configurer.afterConfigurerAdded(this);
+		this.configurers.add(configurer);
+		return (T) this;
+	}
+
+
 	/**
 	 * Build a {@link org.springframework.test.web.servlet.MockMvc} instance.
 	 */
@@ -187,6 +201,10 @@ public abstract class AbstractMockMvcBuilder<B extends AbstractMockMvcBuilder<B>
 		ServletContext servletContext = wac.getServletContext();
 		MockServletConfig mockServletConfig = new MockServletConfig(servletContext);
 
+		for (MockMvcConfigurer configurer : this.configurers) {
+			configurer.beforeMockMvcCreated(this, this.defaultRequestBuilder, wac);
+		}
+
 		Filter[] filterArray = this.filters.toArray(new Filter[this.filters.size()]);
 
 		return super.createMockMvc(filterArray, mockServletConfig, wac, this.defaultRequestBuilder,

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

+/*
+ * Copyright 2002-2014 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 org.springframework.test.web.servlet.MockMvcBuilder;
+import org.springframework.test.web.servlet.RequestBuilder;
+import org.springframework.web.context.WebApplicationContext;
+
+/**
+ * A contract that allows the encapsulation of a "recipe" for configuring a
+ * MockMvcBuilder for some specific purpose. For example a 3rd party library
+ * may use this to provide convenient, easy ways to set up MockMvc.
+ *
+ * <p>Supported via {@link AbstractMockMvcBuilder#add(MockMvcConfigurer)}
+ * with instances of class likely created via static methods, e.g.:
+ *
+ * <pre class="code">
+ * 	MockMvcBuilders.webAppContextSetup(context)
+ * 		.add(myLibrary("foo","bar").myProperty("foo"))
+ * 		.build();
+ * </pre>
+ *
+ * @author Rossen Stoyanchev
+ * @since 4.1
+ */
+public interface MockMvcConfigurer {
+
+
+	/**
+	 * Invoked immediately after a {@code MockMvcConfigurer} is configured via
+	 * {@link AbstractMockMvcBuilder#add(MockMvcConfigurer)}.
+	 */
+	void afterConfigurerAdded(MockMvcBuilder mockMvcBuilder);
+
+	/**
+	 * Invoked just before the MockMvc instance is built providing access to the
+	 * configured "default" RequestBuilder. If a "default" RequestBuilder is
+	 * needed but was not configured and is {@code null}), it can still be added
+	 * via {@link AbstractMockMvcBuilder#defaultRequest}.
+	 */
+	void beforeMockMvcCreated(MockMvcBuilder mockMvcBuilder, RequestBuilder defaultRequestBuilder,
+			WebApplicationContext applicationContext);
+
+}