Trying to verify a method call from abstract class on a mocked service but I get a npe

I stuck since a couple of hours on a test method.

I tried to reproduce a similar situation. I have a service who extend a abstract service with a utility method like this:

public class MyService extends MyAbstractService {
    @Autowired
    private UserRepository userRepository;

    public void whatever(MyDTO myDTO) {
        User user = this.userRepository.findByName(myDTO.userId);
        hello(user.name);
    }
}

abstract class MyAbstractService {
    protected void hello(String userName) {
        System.out.printf("Hello %s", userName);
    }
}

my testing class :

@Test
void whenIcallWhaterver() {
    MyService myService = Mockito.mock(MyService.class, InvocationOnMock::callRealMethod);

    myService.whatever(myDTO);
    verify(myService, only()).hello(anyString());
}

My goal is just to verify if when I go into the method whatever, the method of the abstract service is called too. I got a null pointer exception because the repository isn't not init in the mock (normal behavior I assume), but I would like to learn/understand how test this.

How could I do to fix this?

Thanks for your help

Solution

You are getting a NullPointerException because you are not setting an UserRepository object to MyService.

Note that your test does not load any spring context, so the annotation @Autowired is not taking effect.

So in order to get your test to work either:

add a mock UserRepository to your service via constructor or setter
or load a spring context to your test and add a mock UserRepository.

For example, you could do something like the following:

@SpringBootTest(classes = MyTestConfig.class)
class MyTest {

  @MockBean
  private UserRepository userRepository;

  @SpyBean
  private MyService myService;

  @Test
  void whenIcallWhaterver() {

    // Mocks the response of the userRepository
    final User user = new User();
    user.setName("my-name");
    Mockito.when(this.userRepository.findByName(Mockito.anyString()))
            .thenReturn(user);

    final MyDTO myDTO = new MyDTO();
    myDTO.setUserId("myid");
    this.myService.whatever(myDTO);

    verify(this.myService).hello("my-name");
}

  @Configuration
  static class MyTestConfig {

    @Bean
    public MyService myService() {
        return new MyService();
    }
  }
}