Want to mock a dependency that belongs to another class-CodePudding

What I want to test is abc() method from UserServiceImpl class. Within that method it invokes xyz(), which is belongs to UserDao dependency. In UserDao class it has a dependency of UserRepository and xyz() method uses it. So how can I mock UserRepository dependency when I test abc() method? Really appreciate any kind of help.

    public class UserServiceImpl{

    @Autowired
    UserDao userDao;

    public void abc(){
        userDao.xyz("a");
    }
    }

    public class UserDao{

    @Autowired
    UserRepository userRepository;

    public void xyz(String a){
        Optional<User> userOptional = userRepository.findByName("mike");
    }
    }

CodePudding user response：

If you want to test UserServiceImpl.abc() then mock UserDao and define a return value for UserDao.xyz() I see you have void method without parameter but for the example have String as param and return with a User.

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes={UserServiceImpl.class})
public class UserServiceImplTest{

    @Autowired
    UserServiceImpl userSvc;

    @MockBean
    UserDao userDao;
    
    @Test
    public void abcTest(){
        //define User to return and the mock
        User userToReturn = new User("Mike");

        when(userDao.xyz("mike")).thenReturn(userToReturn);
        User retUser=userSvc.abc("mike");

        //do some assertion...

    }
}

If you want to test UserDao then do this in its own Test class.

CodePudding user response：

If you mock UserDao you don't need to mock UserRepository because only the real UserDao needs it.

And if you move your @Autowired annotation to the constructor it will be easier to inject in your test.

public class UserServiceImpl{


    private final UserDao userDao;

    @Autowired
    public UserServiceImpl(UserDao userDao) {
        this.userDao = userDao;
    }

    public void abc(){
        userDao.xyz("a");
    }

}

Test:

UserDao userDao = mock(UserDao.class);

UserServiceImpl subject = new UserServiceImpl(userDao);
subject.abc();
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