How to mock nested beans when using #SpringBootTest - spring

Question

I am writing Integration tests for one of the apps.
The app architecture has RestController ---> Service ---> Dao/Repo ---> DaoImpl. The application also uses feign clients to connect third-party apps accessed from nested services within the other services.
In the integration test, I am trying to mock third-party integrations like Dao/Repo, and Feign client. I have slice tests written separately for Dao/Repo. I am just trying to test the RestControllers, Services (which has all the business logic), however, I am not able to inject mocks in nested dependencies, like from controller, actual dependency of service is used, but inside Service, Dao/Repo or Fiegn client needs to be mocked so no actual SQL query or HTTP request to other is executed.
Below is my test code for this.
#Slf4j
#AutoConfigureMockMvc
#SpringBootTest
public class TokenControllerTest {
#Autowired
private MockMvc mockMvc;
#MockBean
private AppDao appDao;
#Autowired
private TokenService tokenService;
private ObjectMapper mapper = new ObjectMapper();
#Test
public void givenAppNameAndSecret_shouldReturnWithToken() throws Exception {
AppTokenDTO tokenDTO = AppTokenDTO.builder().appName("dummy").accessToken("uoqiuwe90273492308019238472839423").expiresIn(1800L).build();
App app = AppStub.getApp();
when(appDao.getApp(app.getName(), app.getApiKey())).thenReturn(app);
mockMvc.perform(MockMvcRequestBuilders.post("/tokens")
.contentType(MediaType.APPLICATION_JSON)
.content(mapper.writeValueAsString(app)))
.andDo(MockMvcResultHandlers.print())
.andExpect(MockMvcResultMatchers.status().isOk())
.andExpect(MockMvcResultMatchers.jsonPath("$.data.accessToken").isNotEmpty());
}
The expectation is when the endpoint is accessed from MockMvc, the TokenService from ApplicationContext is loaded, however, AppDao must be mocked inside TokenService.
I am using #SpringBootTest and it is loading the complete context of the application because of which the execution is taking time. I tried replacing #SpringBootTest with #WebMvcText to limit the configuration to the relevant MVC test (I am not sure to know if this needs to be done or not), but the application keeps throwing failed to load ApplicationContext exception.
Below is the expectation that is raised when #WebMvcTest is used.
java.lang.IllegalStateException: Failed to load ApplicationContext
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:132)
at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:124)
at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.postProcessFields(MockitoTestExecutionListener.java:110)
at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.injectFields(MockitoTestExecutionListener.java:94)
at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.prepareTestInstance(MockitoTestExecutionListener.java:61)
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:248)
at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:138)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$8(ClassBasedTestDescriptor.java:363)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.executeAndMaskThrowable(ClassBasedTestDescriptor.java:368)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$9(ClassBasedTestDescriptor.java:363)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:735)
at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)
at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.invokeTestInstancePostProcessors(ClassBasedTestDescriptor.java:362)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$instantiateAndPostProcessTestInstance$6(ClassBasedTestDescriptor.java:283)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.instantiateAndPostProcessTestInstance(ClassBasedTestDescriptor.java:282)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$4(ClassBasedTestDescriptor.java:272)
at java.base/java.util.Optional.orElseGet(Optional.java:369)
at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$5(ClassBasedTestDescriptor.java:271)
at org.junit.jupiter.engine.execution.TestInstancesProvider.getTestInstances(TestInstancesProvider.java:31)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$prepare$0(TestMethodTestDescriptor.java:102)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:101)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:66)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$prepare$2(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.prepare(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:90)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'tokenController': Unsatisfied dependency expressed through field 'tokenService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.myapp.auth.service.TokenService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:659)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:308)
at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:132)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
... 72 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.myapp.auth.service.TokenService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1799)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1355)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656)
... 91 more
Any help is appreciated.

Answer 1

The error you get is No qualifying bean of type 'com.myapp.auth.service.TokenService' available
You need to add this bean into the spring beans test context
#SpringBootTest(classes = {TokenService.class})
OR
#ContextConfiguration(classes = {TokenService.class})

Answer 2

I was able to solve this problem of injecting nested mocks using
#MockBean(answer = Answers.RETURNS_DEEP_STUBS)
private AppDao appDao;
Though the documentation says it is discouraged to be used, in my case, this solves the purpose.
Alternatively RETURNS_MOCKS can also be used as below
#MockBean(answer = Answers.RETURNS_MOCKS)
private AppDao appDao;
If anyone has a better solution, would like to know that.