Beans are null when unit testing spring-retry with SpringRunner

Question

I am trying to write unit tests for a class having spring retry using the springRunner. But my @Autowired beans are null . Could you please let me know what I did wrong?

Below is my test class

@RunWith(SpringRunner.class)
@ContextConfiguration
public class DeltaHelperTest {

    @Autowired
    private DeltaHelper deltaHelper;
    
    @Before
    public void setUp() { System.setProperty("delta.process.retries", "2"); }

    @After
    public void validate() { validateMockitoUsage(); }

    @Test
    public void retriesAfterOneFailAndThenPass() throws Exception {
        when(deltaHelper.restService.call(any(), any())).thenThrow(new HttpException());
        deltaHelper.process(any(),any());
        verify(deltaHelper, times(2)).process(any(), any());
    }

    @Configuration
    @EnableRetry
    @EnableAspectJAutoProxy(proxyTargetClass=true)
    @Import(MockitoSkipAutowireConfiguration.class)

    public static class Application {

        @Bean
        public DeltaHelper deltaHelper() {
            DeltaHelper deltaHelper = new DeltaHelper();
            deltaHelper.myStorageService= myStorageService();
            deltaHelper.restService = restService();
            return deltaHelper;
        }

        @Bean
        public MyStorageService myStorageService() {
            return new MyStorageService();
        }

        @Bean
        public MyRestService restService() {
            return new MyRestService();
        }

        @Bean
        public MyRepo myRepository() {
            return mock(MyRepo.class);
        }
    }


    @Configuration
    public static class MockitoSkipAutowireConfiguration {
        @Bean MockBeanFactory mockBeanFactory() {
            return new MockBeanFactory();
        }
        private static class MockBeanFactory extends InstantiationAwareBeanPostProcessorAdapter {
            @Override
            public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
                return !mockingDetails(bean).isMock();
            }
        }
    }
}

Here test service is null on deltaHelper object .

MyRepo.class is mocked as it has some more @autowired bean reference

Attaching other classes here

@Component
public class DeltaHelper {

    @Autowired
    MyRestService restService;

    @Autowired
    MyStorageService myStorageService;

    @NotNull
    @Retryable(
            value = Exception.class,
            maxAttemptsExpression = "${delta.process.retries}"
    )
    public String process(String api, HttpEntity<?> entity) {
            return restService.call(api, entity);
    }
    @Recover
    public String recover(Exception e, String api, HttpEntity<?> entity) {

            myStorageService.save(api);
            return "recover";
    }
}


@Service
public class MyStorageService {

    @Autowired
    MyRepo myRepo;

    @Async
    public MyEntity save(String api) {
        return myRepo.save(new MyEntity(api, System.currentTimeMillis()));
    }
}



public class MyRestService extends org.springframework.web.client.RestTemplate {
}

Thank you

Tried MockitoJUnitRunner, But found that @Retryable works only when running with Spring

Answer 1

I'm not sure why you are trying to test framework functionality such as retry. Generally, you can assume that framework components have been tested thoroughly by the framework authors.

Ignoring that, I can see at least two problems:

1. deltaHelper is not a mock, but your SUT, yet you try to set up method calls. If you mock your SUT, you are no longer testing your class, you are testing the mock. If you want your call to fail, don't mock the call, but mock its dependencies (e.g. MyRestService restService) and have calls on the dependency throw an exception.

2. You pass ArgumentMatchers.any() in your real method call (the "act" part), but any() unconditionally returns null (not some magic object). If you want to act on your SUT, you must pass real values. any is for setting up mocks or verifying calls on mocks.

   For completeness' sake, here's the source of any():

   public static <T> T any() {
       reportMatcher(Any.ANY);
       return null;
   }