Setting Up Mockito

Sync Your Code to the Start of this Video

git checkout -f v4

Using Git with this Workshop

See the README on Github for information on how to use Git with this repo to follow along with this workshop.

Alternate Approaches to Setting Up Mockito

Without the MockitoJUnitRunner

If you want to run your unit tests without the MockitoJUnitRunner, you can delete the @RunWith annotation from the class. Then, you'll need to tell Mockito to initialize the mocks according to your @InjectMocks and @Mock annotations:

public class FavoriteControllerTest {
  private MockMvc mockMvc;

  @InjectMocks
  private FavoriteController controller;

  @Mock
  private FavoriteService service;

  @Before
  public void setup() {
    MockitoAnnotations.initMocks(this); // Initialize according to annotations
    mockMvc = MockMvcBuilders.standaloneSetup(controller).build();
  }
}

Construct Mocks Yourself

If you'd like to construct and initialize the mocks yourself, you have options. Here is one way to do this:

public class FavoriteControllerTest {
  private MockMvc mockMvc;
  private FavoriteController controller;
  private FavoriteService service;

  @Before
  public void setup() {
    // Construct the service mock
    service = Mockito.mock(FavoriteService.class);
    controller = new FavoriteController(service,null,null);
    mockMvc = MockMvcBuilders.standaloneSetup(controller).build();
  }
}

Of course, this will require a constructor in the FavoriteController class. Because we don't want to break Spring's dependency injection, you can mark this constructor as @Autowired, which means that any parameter values will be injected according to available beans. This is a nice, test-friendly alternative to autowired fields, which require reflection for DI. Here's the relevant part of the FavoriteController class:

@Controller
public class FavoriteController {
  // @Autowired annotations removed from fields

  private FavoriteService favoriteService;
  private PlacesService placesService;
  private WeatherService weatherService;

  @Autowired // Added for Spring DI
  public FavoriteController(
        FavoriteService favoriteService,
        PlacesService placesService,
        WeatherService weatherService) {
     this.favoriteService = favoriteService;
     this.placesService = placesService;
     this.weatherService = weatherService;
  }
} 

Overview of Mocking

Wikipedia has a nice explanation of what mock objects are: https://en.wikipedia.org/wiki/Mock_object

Here is a nice supplement to our mocking work, still within the context of Spring: https://dzone.com/articles/mocking-in-unit-tests

Popular Mocking Libraries

• Mockito
• EasyMock
• PowerMock
• JMockit