Support @ContextHierarchy when using @SpringBootTest

Closes gh-8000

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

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -33,8 +33,10 @@ import org.springframework.boot.web.support.ServletContextApplicationContextInit
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.core.Ordered;
 import org.springframework.core.SpringVersion;
 import org.springframework.core.annotation.AnnotatedElementUtils;
+import org.springframework.core.annotation.Order;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.MapPropertySource;
 import org.springframework.core.env.MutablePropertySources;
@@ -187,6 +189,10 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 				.getContextInitializerClasses()) {
 			initializers.add(BeanUtils.instantiate(initializerClass));
 		}
+		if (config.getParent() != null) {
+			initializers.add(new ParentContextApplicationContextInitializer(
+					config.getParentApplicationContext()));
+		}
 		return initializers;
 	}
 
@@ -295,4 +301,21 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 
 	}
 
+	@Order(Ordered.HIGHEST_PRECEDENCE)
+	private static class ParentContextApplicationContextInitializer
+			implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+		private final ApplicationContext parent;
+
+		ParentContextApplicationContextInitializer(ApplicationContext parent) {
+			this.parent = parent;
+		}
+
+		@Override
+		public void initialize(ConfigurableApplicationContext applicationContext) {
+			applicationContext.setParent(this.parent);
+		}
+
+	}
+
 }

spring-boot-test/src/test/java/org/springframework/boot/test/context/SpringBootTestContextHierarchyTests.java

+/*
+ * Copyright 2012-2017 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.boot.test.context;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.boot.test.context.SpringBootTestContextHierarchyTests.ChildConfiguration;
+import org.springframework.boot.test.context.SpringBootTestContextHierarchyTests.ParentConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.ContextHierarchy;
+import org.springframework.test.context.junit4.SpringRunner;
+
+/**
+ * Tests for {@link SpringBootTest} and {@link ContextHierarchy}.
+ *
+ * @author Andy Wilkinson
+ */
+@SpringBootTest
+@ContextHierarchy({ @ContextConfiguration(classes = ParentConfiguration.class),
+		@ContextConfiguration(classes = ChildConfiguration.class) })
+@RunWith(SpringRunner.class)
+public class SpringBootTestContextHierarchyTests {
+
+	@Test
+	public void contextLoads() {
+
+	}
+
+	@Configuration
+	static class ParentConfiguration {
+
+		@Bean
+		MyBean myBean() {
+			return new MyBean();
+		}
+
+	}
+
+	@Configuration
+	static class ChildConfiguration {
+
+		ChildConfiguration(MyBean myBean) {
+
+		}
+
+	}
+
+	static class MyBean {
+
+	}
+
+}