How to test GWT/GWTP project?

Question

I am currently building a web application using GWT, GWTP.

And I have some questions about testings:

• Is there a Lint-like tool for GWTP or GWT?
• How to test presenters? (GWTP with Mockito)
• How to test views?

Thanks.

Answer 1

Google put out a great article about using different testing methodologies with GWT. Definitely check it out. Personally, I use JUnit when I'm testing back-end stuff like business logic, and Selenium for testing the UI and application as a whole from the browser's perspective.

Answer 2

Presenters can be easily unit-tested using Jukito. Here's a quick example of a Presenter being tested using Jukito.

@RunWith(JukitoRunner.class)
public class ShowCommentsPresenterTest {
    @Inject
    private ShowCommentsPresenter showCommentsPresenter;

    @Inject
    private PlaceManager placeManager;

    @Test
    public void onReset_PlaceRequestHasNoShowId_ShouldHideView() {
        //given
        when(placeManager.getCurrentPlaceRequest()).thenReturn(new PlaceRequest());

        //when
        showCommentsPresenter.onReset();

        //then 
        verify(showCommentsPresenter.getView()).hide();
    }

    @Test
    public void onReset_PlaceRequestHasAShowId_ShouldDisplayView() {
        //given
        String someShowId = "12345";
        when(placeManager.getCurrentPlaceRequest()).thenReturn(new PlaceRequest()
            .with(ParameterTokens.getShowId(), someShowId));

        //when
        showCommentsPresenter.onReset();

        //then
        verify(showCommentsPresenter.getView()).display();
    }
}

In GWTP's philosophy, Views should not be unit-tested directly. Using a dumb View that is a slave to the Presenter, most of the logic can be tested through unit tests on the Presenters. Tools like Selenium are a better fit for testing UI interactivity.