Allow @SpyBean to be used to spy on a Spring Data repository

Fixes gh-7033

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -16,6 +16,9 @@
 
 package org.springframework.boot.test.mock.mockito;
 
+import java.lang.reflect.Proxy;
+
+import org.mockito.AdditionalAnswers;
 import org.mockito.MockSettings;
 import org.mockito.Mockito;
 import org.mockito.listeners.VerificationStartedEvent;
@@ -95,12 +98,20 @@ class SpyDefinition extends Definition {
 		if (StringUtils.hasLength(name)) {
 			settings.name(name);
 		}
-		settings.spiedInstance(instance);
-		settings.defaultAnswer(Mockito.CALLS_REAL_METHODS);
 		if (isProxyTargetAware()) {
 			settings.verificationStartedListeners(new SpringAopBypassingVerificationStartedListener());
 		}
-		return (T) mock(instance.getClass(), settings);
+		Class<?> toSpy;
+		if (Proxy.isProxyClass(instance.getClass())) {
+			settings.defaultAnswer(AdditionalAnswers.delegatesTo(instance));
+			toSpy = this.typeToSpy.toClass();
+		}
+		else {
+			settings.defaultAnswer(Mockito.CALLS_REAL_METHODS);
+			settings.spiedInstance(instance);
+			toSpy = instance.getClass();
+		}
+		return (T) mock(toSpy, settings);
 	}
 
 	/**

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

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2012-2021 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 java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.verify;
+
+/**
+ * Tests for {@link SpyBean @SpyBean} with a JDK proxy.
+ *
+ * @author Andy Wilkinson
+ */
+@ExtendWith(SpringExtension.class)
+public class SpyBeanWithJdkProxyTests {
+
+	@Autowired
+	private ExampleService service;
+
+	@SpyBean
+	private ExampleRepository repository;
+
+	@Test
+	void jdkProxyCanBeSpied() throws Exception {
+		Example example = this.service.find("id");
+		assertThat(example.id).isEqualTo("id");
+		verify(this.repository).find("id");
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@Import(ExampleService.class)
+	static class Config {
+
+		@Bean
+		ExampleRepository dateService() {
+			return (ExampleRepository) Proxy.newProxyInstance(getClass().getClassLoader(),
+					new Class<?>[] { ExampleRepository.class }, new InvocationHandler() {
+
+						@Override
+						public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+							return new Example((String) args[0]);
+						}
+
+					});
+		}
+
+	}
+
+	static class ExampleService {
+
+		private final ExampleRepository repository;
+
+		ExampleService(ExampleRepository repository) {
+			this.repository = repository;
+		}
+
+		Example find(String id) {
+			return this.repository.find(id);
+		}
+
+	}
+
+	interface ExampleRepository {
+
+		Example find(String id);
+
+	}
+
+	static class Example {
+
+		private final String id;
+
+		Example(String id) {
+			this.id = id;
+		}
+
+	}
+
+}

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-data-jpa/src/main/java/smoketest/data/jpa/service/CityRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -22,7 +22,7 @@ import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.repository.Repository;
 
-interface CityRepository extends Repository<City, Long> {
+public interface CityRepository extends Repository<City, Long> {
 
 	Page<City> findAll(Pageable pageable);
 

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-data-jpa/src/test/java/smoketest/data/jpa/SpyBeanSampleDataJpaApplicationTests.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2012-2021 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 smoketest.data.jpa;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import smoketest.data.jpa.service.CityRepository;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.SpyBean;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.WebApplicationContext;
+
+import static org.mockito.Mockito.verify;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Tests for {@link SampleDataJpaApplication} that use {@link SpyBean @SpyBean}.
+ *
+ * @author Andy Wilkinson
+ */
+@SpringBootTest
+@AutoConfigureTestDatabase
+public class SpyBeanSampleDataJpaApplicationTests {
+
+	@Autowired
+	private WebApplicationContext context;
+
+	private MockMvc mvc;
+
+	@SpyBean
+	private CityRepository repository;
+
+	@BeforeEach
+	void setUp() {
+		this.mvc = MockMvcBuilders.webAppContextSetup(this.context).build();
+	}
+
+	@Test
+	void testHome() throws Exception {
+		this.mvc.perform(get("/")).andExpect(status().isOk()).andExpect(content().string("Bath"));
+		verify(this.repository).findByNameAndCountryAllIgnoringCase("Bath", "UK");
+	}
+
+}