Unit Testing in Retrofit for Callback

Question

Here i got a sample of code in presenter. How do i make write a test for onSuccess and onFailure in retrofit call

public void getNotifications(final List

        

Answer 1

When you want to test different responses from service (API) it's probably best to mock it and return what you need.

    @Test
    public void testApiResponse() {
      ApiInterface mockedApiInterface = Mockito.mock(ApiInterface.class);
      Call<UserNotifications> mockedCall = Mockito.mock(Call.class);

      Mockito.when(mockedApiInterface.getNotifications()).thenReturn(mockedCall);

      Mockito.doAnswer(new Answer() {
        @Override
        public Void answer(InvocationOnMock invocation) throws Throwable {
          Callback<UserNotifications> callback = invocation.getArgumentAt(0, Callback.class);

          callback.onResponse(mockedCall, Response.success(new UserNotifications()));
          // or callback.onResponse(mockedCall, Response.error(404. ...);
          // or callback.onFailure(mockedCall, new IOException());

          return null;
        }
      }).when(mockedCall).enqueue(any(Callback.class));

      // inject mocked ApiInterface to your presenter
      // and then mock view and verify calls (and eventually use ArgumentCaptor to access call parameters)
    }