TestMainActivity.java

@Config(constants = BuildConfig.class, sdk = 21, application = TestApplication.class)
@RunWith(RobolectricTestRunner.class)
public class TestMainActivity {

    private MainActivity mainActivity;

    @Before
    public void setUp() throws Exception {
    }

    @Test
    public void addition_isCorrect() throws Exception {
        mainActivity = Robolectric.buildActivity(MainActivity.class).create().visible().get();
        assertEquals("flumbolate test", mainActivity.flumbolate());
    }

}