Expose a TestDispatcherServlet bean in the MockMvcAutoConfiguration

This commit also contains changes to `ServletContextInitializerBeans`.
`ServletContextInitializerBeans` can now be configured to only look
for specific ServletContextInitializer subclasses, defaulting to
ServletContextIntializer.class. `SpringBootMockMvcBuilderCustomizer`
only cares about filters so it was unnecessary to look for all
`ServletContextInitializer`s. Additionally, adapting `Servlet` beans
caused a cycle once the `DispatcherServlet` bean was added and the
customizer only needs to adapt `Filter` beans.

Closes gh-13241

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/MockMvcAutoConfiguration.java

@@ -86,6 +86,12 @@ public class MockMvcAutoConfiguration {
 		return builder.build();
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	public DispatcherServlet dispatcherServlet(MockMvc mockMvc) {
+		return mockMvc.getDispatcherServlet();
+	}
+
 	private static class MockMvcDispatcherServletCustomizer
 			implements DispatcherServletCustomizer {
 

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java

@@ -28,9 +28,11 @@ import javax.servlet.Filter;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.web.servlet.DelegatingFilterProxyRegistrationBean;
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.boot.web.servlet.RegistrationBean;
 import org.springframework.boot.web.servlet.ServletContextInitializer;
 import org.springframework.boot.web.servlet.ServletContextInitializerBeans;
 import org.springframework.context.ApplicationContext;
@@ -106,8 +108,7 @@ public class SpringBootMockMvcBuilderCustomizer implements MockMvcBuilderCustomi
 	}
 
 	private void addFilters(ConfigurableMockMvcBuilder<?> builder) {
-		ServletContextInitializerBeans initializers = new ServletContextInitializerBeans(
-				this.context);
+		FilterRegistrationBeans initializers = new FilterRegistrationBeans(this.context);
 		for (ServletContextInitializer initializer : initializers) {
 			if (initializer instanceof FilterRegistrationBean) {
 				addFilter(builder, (FilterRegistrationBean<?>) initializer);
@@ -319,4 +320,33 @@ public class SpringBootMockMvcBuilderCustomizer implements MockMvcBuilderCustomi
 
 	}
 
+	private static class FilterRegistrationBeans extends ServletContextInitializerBeans {
+
+		FilterRegistrationBeans(ListableBeanFactory beanFactory) {
+			super(beanFactory, FilterRegistrationBean.class,
+					DelegatingFilterProxyRegistrationBean.class);
+		}
+
+		@Override
+		protected void addAdaptableBeans(ListableBeanFactory beanFactory) {
+			addAsRegistrationBean(beanFactory, Filter.class,
+					new FilterRegistrationBeanAdapter());
+		}
+
+		private static class FilterRegistrationBeanAdapter
+				implements RegistrationBeanAdapter<Filter> {
+
+			@Override
+			public RegistrationBean createRegistrationBean(String name, Filter source,
+					int totalNumberOfSourceBeans) {
+				FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>(
+						source);
+				bean.setName(name);
+				return bean;
+			}
+
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/web/servlet/MockMvcAutoConfigurationTests.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2012-2018 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.autoconfigure.web.servlet;
+
+import org.junit.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.servlet.DispatcherServlet;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link MockMvcAutoConfiguration}.
+ *
+ * @author Madhura Bhave
+ */
+public class MockMvcAutoConfigurationTests {
+
+	private WebApplicationContextRunner contextRunner = new WebApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(MockMvcAutoConfiguration.class));
+
+	@Test
+	public void registersDispatcherServletFromMockMvc() {
+		this.contextRunner.run((context) -> {
+			MockMvc mockMvc = context.getBean(MockMvc.class);
+			assertThat(context).hasSingleBean(DispatcherServlet.class);
+			assertThat(context.getBean(DispatcherServlet.class))
+					.isEqualTo(mockMvc.getDispatcherServlet());
+		});
+	}
+
+}

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizerTests.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2012-2018 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.autoconfigure.web.servlet;
+
+import java.util.List;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServlet;
+
+import org.junit.Test;
+
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.mock.web.MockServletContext;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SpringBootMockMvcBuilderCustomizer}.
+ *
+ * @author Madhura Bhave
+ */
+public class SpringBootMockMvcBuilderCustomizerTests {
+
+	private SpringBootMockMvcBuilderCustomizer customizer;
+
+	@Test
+	@SuppressWarnings("unchecked")
+	public void customizeShouldAddFilters() {
+		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+		MockServletContext servletContext = new MockServletContext();
+		context.setServletContext(servletContext);
+		context.register(ServletConfiguration.class, FilterConfiguration.class);
+		context.refresh();
+		DefaultMockMvcBuilder builder = MockMvcBuilders.webAppContextSetup(context);
+		this.customizer = new SpringBootMockMvcBuilderCustomizer(context);
+		this.customizer.customize(builder);
+		FilterRegistrationBean registrationBean = (FilterRegistrationBean) context
+				.getBean("filterRegistrationBean");
+		Filter testFilter = (Filter) context.getBean("testFilter");
+		Filter otherTestFilter = registrationBean.getFilter();
+		List<Filter> filters = (List<Filter>) ReflectionTestUtils.getField(builder,
+				"filters");
+		assertThat(filters).containsExactlyInAnyOrder(testFilter, otherTestFilter);
+	}
+
+	static class ServletConfiguration {
+
+		@Bean
+		public TestServlet testServlet() {
+			return new TestServlet();
+		}
+
+	}
+
+	static class FilterConfiguration {
+
+		@Bean
+		public FilterRegistrationBean<OtherTestFilter> filterRegistrationBean() {
+			return new FilterRegistrationBean<>(new OtherTestFilter());
+		}
+
+		@Bean
+		public TestFilter testFilter() {
+			return new TestFilter();
+		}
+
+	}
+
+	static class TestServlet extends HttpServlet {
+
+	}
+
+	static class TestFilter implements Filter {
+
+		@Override
+		public void init(FilterConfig filterConfig) {
+
+		}
+
+		@Override
+		public void doFilter(ServletRequest request, ServletResponse response,
+				FilterChain chain) {
+
+		}
+
+		@Override
+		public void destroy() {
+
+		}
+
+	}
+
+	static class OtherTestFilter implements Filter {
+
+		@Override
+		public void init(FilterConfig filterConfig) {
+
+		}
+
+		@Override
+		public void doFilter(ServletRequest request, ServletResponse response,
+				FilterChain chain) {
+
+		}
+
+		@Override
+		public void destroy() {
+
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/ServletContextInitializerBeans.java

@@ -18,6 +18,7 @@ package org.springframework.boot.web.servlet;
 
 import java.util.AbstractCollection;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.EventListener;
@@ -73,10 +74,16 @@ public class ServletContextInitializerBeans
 
 	private final MultiValueMap<Class<?>, ServletContextInitializer> initializers;
 
+	private final List<Class<? extends ServletContextInitializer>> initializerTypes;
+
 	private List<ServletContextInitializer> sortedList;
 
-	public ServletContextInitializerBeans(ListableBeanFactory beanFactory) {
+	public ServletContextInitializerBeans(ListableBeanFactory beanFactory,
+			Class<? extends ServletContextInitializer>... initializerTypes) {
 		this.initializers = new LinkedMultiValueMap<>();
+		this.initializerTypes = (initializerTypes.length != 0
+				? Arrays.asList(initializerTypes)
+				: Collections.singletonList(ServletContextInitializer.class));
 		addServletContextInitializerBeans(beanFactory);
 		addAdaptableBeans(beanFactory);
 		List<ServletContextInitializer> sortedInitializers = this.initializers.values()
@@ -88,12 +95,14 @@ public class ServletContextInitializerBeans
 	}
 
 	private void addServletContextInitializerBeans(ListableBeanFactory beanFactory) {
-		for (Entry<String, ServletContextInitializer> initializerBean : getOrderedBeansOfType(
-				beanFactory, ServletContextInitializer.class)) {
+		for (Class<? extends ServletContextInitializer> initializerType : this.initializerTypes) {
+			for (Entry<String, ? extends ServletContextInitializer> initializerBean : getOrderedBeansOfType(
+					beanFactory, initializerType)) {
 				addServletContextInitializerBean(initializerBean.getKey(),
 						initializerBean.getValue(), beanFactory);
 			}
 		}
+	}
 
 	private void addServletContextInitializerBean(String beanName,
 			ServletContextInitializer initializer, ListableBeanFactory beanFactory) {
@@ -152,7 +161,7 @@ public class ServletContextInitializerBeans
 	}
 
 	@SuppressWarnings("unchecked")
-	private void addAdaptableBeans(ListableBeanFactory beanFactory) {
+	protected void addAdaptableBeans(ListableBeanFactory beanFactory) {
 		MultipartConfigElement multipartConfig = getMultipartConfig(beanFactory);
 		addAsRegistrationBean(beanFactory, Servlet.class,
 				new ServletRegistrationBeanAdapter(multipartConfig));
@@ -172,8 +181,8 @@ public class ServletContextInitializerBeans
 		return (beans.isEmpty() ? null : beans.get(0).getValue());
 	}
 
-	private <T> void addAsRegistrationBean(ListableBeanFactory beanFactory, Class<T> type,
-			RegistrationBeanAdapter<T> adapter) {
+	protected <T> void addAsRegistrationBean(ListableBeanFactory beanFactory,
+			Class<T> type, RegistrationBeanAdapter<T> adapter) {
 		addAsRegistrationBean(beanFactory, type, type, adapter);
 	}
 
@@ -248,8 +257,10 @@ public class ServletContextInitializerBeans
 	/**
 	 * Adapter to convert a given Bean type into a {@link RegistrationBean} (and hence a
 	 * {@link ServletContextInitializer}).
+	 *
+	 * @param <T> the type of the Bean to adapt
 	 */
-	private interface RegistrationBeanAdapter<T> {
+	protected interface RegistrationBeanAdapter<T> {
 
 		RegistrationBean createRegistrationBean(String name, T source,
 				int totalNumberOfSourceBeans);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/ServletContextInitializerBeansTests.java

@@ -20,6 +20,7 @@ import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
 import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServlet;
@@ -59,7 +60,17 @@ public class ServletContextInitializerBeansTests {
 		assertThat(initializerBeans.iterator()).hasOnlyElementsOfType(TestFilter.class);
 	}
 
-	private void load(Class<?> configuration) {
+	@Test
+	public void looksForInitializerBeansOfSpecifiedType() {
+		load(TestConfiguration.class);
+		ServletContextInitializerBeans initializerBeans = new ServletContextInitializerBeans(
+				this.context.getBeanFactory(), TestServletContextInitializer.class);
+		assertThat(initializerBeans.size()).isEqualTo(1);
+		assertThat(initializerBeans.iterator())
+				.hasOnlyElementsOfType(TestServletContextInitializer.class);
+	}
+
+	private void load(Class<?>... configuration) {
 		this.context = new AnnotationConfigApplicationContext(configuration);
 	}
 
@@ -81,6 +92,20 @@ public class ServletContextInitializerBeansTests {
 
 	}
 
+	static class TestConfiguration {
+
+		@Bean
+		public TestServletContextInitializer testServletContextInitializer() {
+			return new TestServletContextInitializer();
+		}
+
+		@Bean
+		public OtherTestServletContextInitializer otherTestServletContextInitializer() {
+			return new OtherTestServletContextInitializer();
+		}
+
+	}
+
 	static class TestServlet extends HttpServlet implements ServletContextInitializer {
 
 		@Override
@@ -115,4 +140,22 @@ public class ServletContextInitializerBeansTests {
 
 	}
 
+	static class TestServletContextInitializer implements ServletContextInitializer {
+
+		@Override
+		public void onStartup(ServletContext servletContext) throws ServletException {
+
+		}
+
+	}
+
+	static class OtherTestServletContextInitializer implements ServletContextInitializer {
+
+		@Override
+		public void onStartup(ServletContext servletContext) throws ServletException {
+
+		}
+
+	}
+
 }