Fail fast if @WebAppConfiguration is used with a non-mock web environement

@WebAppConfiguration expects a mock web environment. If it is used
in conjuction with @SpringBootTest configured with a RANDOM_PORT or
DEFINED_PORT web environment a null pointer exception occurs as an
assumption that's made by MockServerContainerContextCustomizer doesn't
hold true in a non-mock web environment.

This commit updates SpringBootTestContextBootstrap to detect the
illegal configuration combination and fail fast, advising the user
to remove @WebAppConfiguration or reconfigure @SpringBootTest.

Closes gh-6795

spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestContextBootstrapper.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.test.context;
 
+import java.lang.annotation.Annotation;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -75,6 +76,7 @@ public class SpringBootTestContextBootstrapper extends DefaultTestContextBootstr
 	@Override
 	public TestContext buildTestContext() {
 		TestContext context = super.buildTestContext();
+		verifyConfiguration(context.getTestClass());
 		WebEnvironment webEnvironment = getWebEnvironment(context.getTestClass());
 		if (webEnvironment == WebEnvironment.MOCK && hasWebEnvironmentClasses()) {
 			context.setAttribute(ACTIVATE_SERVLET_LISTENER, true);
@@ -261,6 +263,24 @@ public class SpringBootTestContextBootstrapper extends DefaultTestContextBootstr
 		return AnnotatedElementUtils.getMergedAnnotation(testClass, SpringBootTest.class);
 	}
 
+	protected void verifyConfiguration(Class<?> testClass) {
+		SpringBootTest springBootTest = getAnnotation(testClass);
+		if (springBootTest != null
+				&& (springBootTest.webEnvironment() == WebEnvironment.DEFINED_PORT
+						|| springBootTest.webEnvironment() == WebEnvironment.RANDOM_PORT)
+				&& getAnnotation(WebAppConfiguration.class, testClass) != null) {
+			throw new IllegalStateException("@WebAppConfiguration should only be used "
+					+ "with @SpringBootTest when @SpringBootTest is configured with a "
+					+ "mock web environment. Please remove @WebAppConfiguration or "
+					+ "reconfigure @SpringBootTest.");
+		}
+	}
+
+	private <T extends Annotation> T getAnnotation(Class<T> annotationType,
+			Class<?> testClass) {
+		return AnnotatedElementUtils.getMergedAnnotation(testClass, annotationType);
+	}
+
 	/**
 	 * Create a new {@link MergedContextConfiguration} with different classes.
 	 * @param mergedConfig the source config

spring-boot-test/src/test/java/org/springframework/boot/test/context/bootstrap/SpringBootTestContextBootstrapperExampleConfig.java

@@ -19,7 +19,7 @@ package org.springframework.boot.test.context.bootstrap;
 import org.springframework.boot.SpringBootConfiguration;
 
 /**
- * Example configuration used in {@link SpringBootTestContextBootstrapperTests}.
+ * Example configuration used in {@link SpringBootTestContextBootstrapperIntegrationTests}.
  *
  * @author Phillip Webb
  */

spring-boot-test/src/test/java/org/springframework/boot/test/context/bootstrap/SpringBootTestContextBootstrapperIntegrationTests.java

@@ -0,0 +1,91 @@
+/*
+ * 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.
+ * 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.context.bootstrap;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.stereotype.Component;
+import org.springframework.test.context.BootstrapWith;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for {@link SpringBootTestContextBootstrapper} (in its own package so
+ * we can test detection).
+ *
+ * @author Phillip Webb
+ */
+@RunWith(SpringRunner.class)
+@BootstrapWith(SpringBootTestContextBootstrapper.class)
+public class SpringBootTestContextBootstrapperIntegrationTests {
+
+	@Autowired
+	private ApplicationContext context;
+
+	@Autowired
+	private SpringBootTestContextBootstrapperExampleConfig config;
+
+	boolean defaultTestExecutionListenersPostProcessorCalled = false;
+
+	@Test
+	public void findConfigAutomatically() throws Exception {
+		assertThat(this.config).isNotNull();
+	}
+
+	@Test
+	public void contextWasCreatedViaSpringApplication() throws Exception {
+		assertThat(this.context.getId()).startsWith("application:");
+	}
+
+	@Test
+	public void testConfigurationWasApplied() throws Exception {
+		assertThat(this.context.getBean(ExampleBean.class)).isNotNull();
+	}
+
+	@Test
+	public void defaultTestExecutionListenersPostProcessorShouldBeCalled()
+			throws Exception {
+		assertThat(this.defaultTestExecutionListenersPostProcessorCalled).isTrue();
+	}
+
+	@TestConfiguration
+	static class TestConfig {
+
+		@Bean
+		public ExampleBean exampleBean() {
+			return new ExampleBean();
+		}
+
+	}
+
+	static class ExampleBean {
+
+	}
+
+	@Component
+	static class ExampleTestComponent {
+
+	}
+
+}

spring-boot-test/src/test/java/org/springframework/boot/test/context/bootstrap/SpringBootTestContextBootstrapperTests.java

@@ -16,75 +16,67 @@
 
 package org.springframework.boot.test.context.bootstrap;
 
+import org.junit.Rule;
 import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.rules.ExpectedException;
 
-import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
-import org.springframework.boot.test.context.TestConfiguration;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.annotation.Bean;
-import org.springframework.stereotype.Component;
-import org.springframework.test.context.BootstrapWith;
-import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.BootstrapContext;
+import org.springframework.test.context.CacheAwareContextLoaderDelegate;
+import org.springframework.test.context.web.WebAppConfiguration;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
 
 /**
- * Tests for {@link SpringBootTestContextBootstrapper} (in its own package so we can test
- * detection).
+ * Tests for {@link SpringBootTestContextBootstrapper}.
  *
- * @author Phillip Webb
+ * @author Andy Wilkinson
  */
-@RunWith(SpringRunner.class)
-@BootstrapWith(SpringBootTestContextBootstrapper.class)
 public class SpringBootTestContextBootstrapperTests {
 
-	@Autowired
-	private ApplicationContext context;
-
-	@Autowired
-	private SpringBootTestContextBootstrapperExampleConfig config;
-
-	public boolean defaultTestExecutionListenersPostProcessorCalled;
-
-	@Test
-	public void findConfigAutomatically() throws Exception {
-		assertThat(this.config).isNotNull();
-	}
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
 
 	@Test
-	public void contextWasCreatedViaSpringApplication() throws Exception {
-		assertThat(this.context.getId()).startsWith("application:");
+	public void springBootTestWithANonMockWebEnvironmentAndWebAppConfigurationFailsFast() {
+		this.thrown.expect(IllegalStateException.class);
+		this.thrown.expectMessage("@WebAppConfiguration should only be used with "
+				+ "@SpringBootTest when @SpringBootTest is configured with a mock web "
+				+ "environment. Please remove @WebAppConfiguration or reconfigure "
+				+ "@SpringBootTest.");
+		buildTestContext(SpringBootTestNonMockWebEnvironmentAndWebAppConfiguration.class);
 	}
 
 	@Test
-	public void testConfigurationWasApplied() throws Exception {
-		assertThat(this.context.getBean(ExampleBean.class)).isNotNull();
+	public void springBootTestWithAMockWebEnvironmentCanBeUsedWithWebAppConfiguration() {
+		buildTestContext(SpringBootTestMockWebEnvironmentAndWebAppConfiguration.class);
 	}
 
-	@Test
-	public void defaultTestExecutionListenersPostProcessorShouldBeCalled()
-			throws Exception {
-		assertThat(this.defaultTestExecutionListenersPostProcessorCalled).isTrue();
-	}
-
-	@TestConfiguration
-	static class TestConfig {
-
-		@Bean
-		public ExampleBean exampleBean() {
-			return new ExampleBean();
-		}
-
+	@SuppressWarnings("rawtypes")
+	private void buildTestContext(Class<?> testClass) {
+		SpringBootTestContextBootstrapper bootstrapper = new SpringBootTestContextBootstrapper();
+		BootstrapContext bootstrapContext = mock(BootstrapContext.class);
+		bootstrapper.setBootstrapContext(bootstrapContext);
+		given((Class) bootstrapContext.getTestClass()).willReturn(testClass);
+		CacheAwareContextLoaderDelegate contextLoaderDeleagte = mock(
+				CacheAwareContextLoaderDelegate.class);
+		given(bootstrapContext.getCacheAwareContextLoaderDelegate())
+				.willReturn(contextLoaderDeleagte);
+		bootstrapper.buildTestContext();
 	}
 
-	static class ExampleBean {
+	@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+	@WebAppConfiguration
+	private static class SpringBootTestNonMockWebEnvironmentAndWebAppConfiguration {
 
 	}
 
-	@Component
-	static class ExampleTestComponent {
+	@SpringBootTest
+	@WebAppConfiguration
+	private static class SpringBootTestMockWebEnvironmentAndWebAppConfiguration {
 
 	}
 

spring-boot-test/src/test/java/org/springframework/boot/test/context/bootstrap/TestDefaultTestExecutionListenersPostProcessor.java

@@ -43,8 +43,8 @@ public class TestDefaultTestExecutionListenersPostProcessor
 		@Override
 		public void prepareTestInstance(TestContext testContext) throws Exception {
 			Object testInstance = testContext.getTestInstance();
-			if (testInstance instanceof SpringBootTestContextBootstrapperTests) {
-				SpringBootTestContextBootstrapperTests test = (SpringBootTestContextBootstrapperTests) testInstance;
+			if (testInstance instanceof SpringBootTestContextBootstrapperIntegrationTests) {
+				SpringBootTestContextBootstrapperIntegrationTests test = (SpringBootTestContextBootstrapperIntegrationTests) testInstance;
 				test.defaultTestExecutionListenersPostProcessorCalled = true;
 			}
 		}