Make MockBean resolve right type for abstract test class

Fixes gh-20916

Author: mbhave

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/DefinitionsParser.java

@@ -60,20 +60,20 @@ class DefinitionsParser {
 	}
 
 	void parse(Class<?> source) {
-		parseElement(source);
-		ReflectionUtils.doWithFields(source, this::parseElement);
+		parseElement(source, null);
+		ReflectionUtils.doWithFields(source, (element) -> parseElement(element, source));
 	}
 
-	private void parseElement(AnnotatedElement element) {
+	private void parseElement(AnnotatedElement element, Class<?> source) {
 		MergedAnnotations annotations = MergedAnnotations.from(element, SearchStrategy.SUPERCLASS);
 		annotations.stream(MockBean.class).map(MergedAnnotation::synthesize)
-				.forEach((annotation) -> parseMockBeanAnnotation(annotation, element));
+				.forEach((annotation) -> parseMockBeanAnnotation(annotation, element, source));
 		annotations.stream(SpyBean.class).map(MergedAnnotation::synthesize)
-				.forEach((annotation) -> parseSpyBeanAnnotation(annotation, element));
+				.forEach((annotation) -> parseSpyBeanAnnotation(annotation, element, source));
 	}
 
-	private void parseMockBeanAnnotation(MockBean annotation, AnnotatedElement element) {
-		Set<ResolvableType> typesToMock = getOrDeduceTypes(element, annotation.value());
+	private void parseMockBeanAnnotation(MockBean annotation, AnnotatedElement element, Class<?> source) {
+		Set<ResolvableType> typesToMock = getOrDeduceTypes(element, annotation.value(), source);
 		Assert.state(!typesToMock.isEmpty(), () -> "Unable to deduce type to mock from " + element);
 		if (StringUtils.hasLength(annotation.name())) {
 			Assert.state(typesToMock.size() == 1, "The name attribute can only be used when mocking a single class");
@@ -86,8 +86,8 @@ private void parseMockBeanAnnotation(MockBean annotation, AnnotatedElement eleme
 		}
 	}
 
-	private void parseSpyBeanAnnotation(SpyBean annotation, AnnotatedElement element) {
-		Set<ResolvableType> typesToSpy = getOrDeduceTypes(element, annotation.value());
+	private void parseSpyBeanAnnotation(SpyBean annotation, AnnotatedElement element, Class<?> source) {
+		Set<ResolvableType> typesToSpy = getOrDeduceTypes(element, annotation.value(), source);
 		Assert.state(!typesToSpy.isEmpty(), () -> "Unable to deduce type to spy from " + element);
 		if (StringUtils.hasLength(annotation.name())) {
 			Assert.state(typesToSpy.size() == 1, "The name attribute can only be used when spying a single class");
@@ -108,13 +108,13 @@ private void addDefinition(AnnotatedElement element, Definition definition, Stri
 		}
 	}
 
-	private Set<ResolvableType> getOrDeduceTypes(AnnotatedElement element, Class<?>[] value) {
+	private Set<ResolvableType> getOrDeduceTypes(AnnotatedElement element, Class<?>[] value, Class<?> source) {
 		Set<ResolvableType> types = new LinkedHashSet<>();
 		for (Class<?> clazz : value) {
 			types.add(ResolvableType.forClass(clazz));
 		}
 		if (types.isEmpty() && element instanceof Field) {
-			types.add(ResolvableType.forField((Field) element));
+			types.add(ResolvableType.forField((Field) element, source));
 		}
 		return types;
 	}

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/mock/mockito/AbstractMockBeanOnGenericExtensionTests.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2012-2020 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
+ *
+ *      https://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.mock.mockito;
+
+/**
+ * Concrete implementation of {@link AbstractMockBeanOnGenericTests}.
+ *
+ * @author Madhura Bhave
+ */
+class AbstractMockBeanOnGenericExtensionTests extends
+		AbstractMockBeanOnGenericTests<AbstractMockBeanOnGenericTests.ThingImpl, AbstractMockBeanOnGenericTests.SomethingImpl> {
+
+}

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/mock/mockito/AbstractMockBeanOnGenericTests.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2012-2020 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
+ *
+ *      https://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.mock.mockito;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link MockBean} with abstract class and generics.
+ *
+ * @author Madhura Bhave
+ */
+@SpringBootTest(classes = AbstractMockBeanOnGenericTests.TestConfiguration.class)
+abstract class AbstractMockBeanOnGenericTests<T extends AbstractMockBeanOnGenericTests.Thing<U>, U extends AbstractMockBeanOnGenericTests.Something> {
+
+	@Autowired
+	private T thing;
+
+	@MockBean
+	private U something;
+
+	@Test
+	void mockBeanShouldResolveConcreteType() {
+		assertThat(this.something).isInstanceOf(SomethingImpl.class);
+	}
+
+	abstract static class Thing<T extends AbstractMockBeanOnGenericTests.Something> {
+
+		@Autowired
+		private T something;
+
+		T getSomething() {
+			return this.something;
+		}
+
+		void setSomething(T something) {
+			this.something = something;
+		}
+
+	}
+
+	static class SomethingImpl extends Something {
+
+	}
+
+	static class ThingImpl extends Thing<SomethingImpl> {
+
+	}
+
+	static class Something {
+
+	}
+
+	@Configuration
+	static class TestConfiguration {
+
+		@Bean
+		ThingImpl thing() {
+			return new ThingImpl();
+		}
+
+	}
+
+}