Mokcito not mocking the DAO layer

Question

I have a Spring MVC application. It has Controller, Service and Dao. I would like to test only the Controller and Service by Mocking the DAO layer using Mockito.

My Controller class:

@Controller
@RequestMapping(value="/audit")
public class AuditController {

   @Autowired
   AuditService auditService;

   ...
}

My Service class:

@Service
public class AuditService {

   @Autowired
   AuditDao auditDao;

   ....
}

My Test class:

@RunWith(SptringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/dispatcher-servlet.xml", "spring-context.xml"})
@WebAppConfiguration
public class AuditControllerTest {

   private MockMvc mockMvc;

   @Mock
   AuditDao auditDao;

   @Autowired
   private WebApplicationContext webApplicationContext;

   @Before
   public void setUp() {
       MockitAnnotations.initMocks(this);
       mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
   }


  @Test
  public void testGetAudit() {

      Mockito.when(auditDao.getAudit(Mockito.any(Long.class))).thenReturn(new Audit(1L));
      mockMvc.perform(get("/audit/{id}", "1")).andExpect(status().isOk());
  }
}

PROBLEM: It performs the call fine by going through autowired controller and Service. However, from the Service the DAO calls are going to a real DAO not the Mocked DAO.

1. I understand that the DAO is autowired to the real Dao, however I am not sure how to replace that Dao with the Mock one from the Test.

2. Keeping the Dao in the controller and using @InjectMock to the controller works fine, but I want to keep the Dao in the Service and test only the controller and Service, but mock the Dao alone.

3. I suspect that this issue is to do with the contexts (web application context and the MockMvc context), however I am not sure how to resolve it.

Any help would be greatly appreciated. Thanks in advance.

Answer 1

First I would suggest avoiding Autowired fields and have you class explicitly expose their dependencies via constructor dependencies

Controller class:

@Controller
@RequestMapping(value="/audit")
public class AuditController {
    private final AuditService auditService;

    @Autowired
    public AuditController(AuditService auditService) {
        this.auditService = auditService
    }

    //...
}

Service class:

@Service
public class AuditService {            
    private final AuditDao auditDao;

    @Autowired
    public AuditService(AuditDao auditDao) {
        this.auditDao = auditDao;
    }

    //....
}

I was thinking of something along the line of

@RunWith(SptringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/dispatcher-servlet.xml", "spring-context.xml"})
@WebAppConfiguration
public class AuditControllerTest {

    private MockMvc mockMvc;

    @Mock
    AuditDao auditDao;

    @InjectMock
    AuditService auditService;

    @Before
    public void setUp() {
        MockitAnnotations.initMocks(this);
        AuditController controller = new AuditController (auditService);
        mockMvc = MockMvcBuilders.standaloneSetup(controller).build();
    }

    @Test
    public void testGetAudit() {

      Mockito.when(auditDao.getAudit(Mockito.any(Long.class))).thenReturn(new Audit(1L));
      mockMvc.perform(get("/audit/{id}", "1")).andExpect(status().isOk());
    }
}

But am uncertain if it will behave as expected when exercised.