Events Presenter Test

gistfile1.txt

public class EventsPresenterTest {

    private static List<Event> EVENTS = new ArrayList<>();

    @Mock
    EventsRepository eventsRepository;
    @Mock
    EventsContract.View eventsView;

    private EventsPresenter eventsPresenter;

    /**
     * {@link ArgumentCaptor} is a powerful Mockito API to capture argument values and use them to
     * perform further actions or assertions on them.
     */
    @Captor
    private ArgumentCaptor<EventsDataSource.LoadEventsCallback> loadEventsCallbackCaptor;

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
        eventsPresenter = new EventsPresenter(eventsRepository, eventsView);

        // Test data
        EVENTS.add(
                new Event("1", "Pizza Fest", "Pizza Everywhere", 33928672270000L,
                        "www.pizza.com", "pizza", true));

        EVENTS.add(
                new Event("2", "Beer", "Duff Everywhere", 33928672270777L,
                        "www.duffman.com", "beer", true));

    }

    @Test
    public void loadAllEventsFromRepositoryAndLoadIntoView() {

        eventsPresenter.loadEvents();

        // Callback is captured and invoked with stubbed events
        
        verify(eventsRepository).getEvents(loadEventsCallbackCaptor.capture());
        
        loadEventsCallbackCaptor.getValue().onEventsLoaded(EVENTS);

        //Verify that view is given a list of one event from the presenter
        
        ArgumentCaptor<List> showEventsArgumentCaptor = ArgumentCaptor.forClass(List.class);
        
        verify(eventsView).showEvents(showEventsArgumentCaptor.capture());
        
        assertTrue(showEventsArgumentCaptor.getValue().size() == 2);
    }
}