Set web application context on ServletContext in plain web app tests

Previously, the web application context was only set on the
ServletContext in a full-blown integration test or when MockMvc was
used.

This commit updates SpringApplicationContextLoader so that the context
is also set on the context in a plain web application test (one where
MockMvc is not being used). The change is a partial backport of commit
7dffb702.

Closes gh-4370

spring-boot/src/main/java/org/springframework/boot/context/web/ServletContextApplicationContextInitializer.java

 /*
- * Copyright 2010-2012 the original author or authors.
+ * Copyright 2010-2016 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.
@@ -18,14 +18,17 @@ package org.springframework.boot.context.web;
 
 import javax.servlet.ServletContext;
 
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.core.Ordered;
 import org.springframework.web.context.ConfigurableWebApplicationContext;
+import org.springframework.web.context.WebApplicationContext;
 
 /**
  * {@link ApplicationContextInitializer} for setting the servlet context.
  *
  * @author Dave Syer
+ * @author Phillip Webb
  */
 public class ServletContextApplicationContextInitializer implements
 		ApplicationContextInitializer<ConfigurableWebApplicationContext>, Ordered {
@@ -34,12 +37,27 @@ public class ServletContextApplicationContextInitializer implements
 
 	private final ServletContext servletContext;
 
+	private final boolean addApplicationContextAttribute;
+
 	/**
 	 * Create a new {@link ServletContextApplicationContextInitializer} instance.
 	 * @param servletContext the servlet that should be ultimately set.
 	 */
 	public ServletContextApplicationContextInitializer(ServletContext servletContext) {
+		this(servletContext, false);
+	}
+
+	/**
+	 * Create a new {@link ServletContextApplicationContextInitializer} instance.
+	 * @param servletContext the servlet that should be ultimately set.
+	 * @param addApplicationContextAttribute if the {@link ApplicationContext} should be
+	 * stored as an attribute in the {@link ServletContext}
+	 * @since 1.3.4
+	 */
+	public ServletContextApplicationContextInitializer(ServletContext servletContext,
+			boolean addApplicationContextAttribute) {
 		this.servletContext = servletContext;
+		this.addApplicationContextAttribute = addApplicationContextAttribute;
 	}
 
 	public void setOrder(int order) {
@@ -54,6 +72,12 @@ public class ServletContextApplicationContextInitializer implements
 	@Override
 	public void initialize(ConfigurableWebApplicationContext applicationContext) {
 		applicationContext.setServletContext(this.servletContext);
+		if (this.addApplicationContextAttribute) {
+			this.servletContext.setAttribute(
+					WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE,
+					applicationContext);
+		}
+
 	}
 
 }

spring-boot/src/main/java/org/springframework/boot/test/SpringApplicationContextLoader.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -241,8 +241,8 @@ public class SpringApplicationContextLoader extends AbstractContextLoader {
 				WebMergedContextConfiguration webConfiguration) {
 			SpringBootMockServletContext servletContext = new SpringBootMockServletContext(
 					webConfiguration.getResourceBasePath());
-			initializers.add(0,
-					new ServletContextApplicationContextInitializer(servletContext));
+			initializers.add(0, new ServletContextApplicationContextInitializer(
+					servletContext, true));
 		}
 
 	}

spring-boot/src/test/java/org/springframework/boot/test/SpringApplicationMockMvcTests.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -41,7 +41,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 /**
- * Tests for {@link WebAppConfiguration} integration.
+ * Tests for {@link WebAppConfiguration} with {@link MockMvc}.
  *
  * @author Stephane Nicoll
  */

spring-boot/src/test/java/org/springframework/boot/test/SpringApplicationMockServletTests.java

+/*
+ * Copyright 2012-2015 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.boot.test;
+
+import javax.servlet.ServletContext;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.SpringApplicationMockServletTests.Config;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.context.support.WebApplicationContextUtils;
+
+import static org.junit.Assert.assertSame;
+
+/**
+ * Tests for {@link WebAppConfiguration} with a plain mock Servlet environment.
+ *
+ * @author Andy Wilkinson
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = Config.class)
+@WebAppConfiguration
+public class SpringApplicationMockServletTests {
+
+	@Autowired
+	private WebApplicationContext context;
+
+	@Autowired
+	private ServletContext servletContext;
+
+	@Test
+	public void webApplicationContextIsSetOnServletContext() {
+		assertSame(this.context,
+				WebApplicationContextUtils.getWebApplicationContext(this.servletContext));
+	}
+
+	@Configuration
+	protected static class Config {
+
+	}
+
+}