Android functional testing with Dagger

Question

I’m trying to test an Activity with Mockito & Dagger. I have been able to inject dependencies to Activity in my application but when testing the Activity, I have not been able to inject mock to the Activity. Should I inject Activity to test or let getActivity() create it?

public class MainActivityTest extends
    ActivityInstrumentationTestCase2<MainActivity> {

@Inject Engine engineMock;
private MainActivity mActivity;
private Button mLogoutBtn;


public MainActivityTest() {
    super(MainActivity.class);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    // Inject engineMock to test
    ObjectGraph.create(new TestModule()).inject(this);
}

@Override
protected void tearDown() {
    if (mActivity != null)
        mActivity.finish();
}

 @Module(
 includes = MainModule.class,
 entryPoints = MainActivityTest.class,
 overrides = true
 )

static class TestModule {
    @Provides
    @Singleton
    Engine provideEngine() {
        return mock(Engine.class);
    }
}

@UiThreadTest
public void testLogoutButton() {

    when(engineMock.isLoggedIn()).thenReturn(true);

    mActivity = getActivity();
    mLogoutBtn = (Button) mActivity.findViewById(R.id.logoutButton);

    // how to inject engineMock to Activity under test?
    ObjectGraph.create(new TestModule()).inject(this.mActivity);

    assertTrue(mLogoutBtn.isEnabled() == true);
}
}

Answer 1

I use Mockito and Dagger for functional testing. The key concept is that your test class inherits from ActivityUnitTestCase, instead of ActivityInstrumentationTestCase2; the latter super-class call onStart() life-cycle method of Activity blocking you for inject your test doubles dependencies, but with first super-class you can handle the life-cycle more fine-grained.

You can see my working examples using dagger-1.0.0 and mockito for test Activities and Fragments in:

https://github.com/IIIRepublica/android-civicrm-test

The project under test is in:

https://github.com/IIIRepublica/android-civicrm

Hope this helps you