Espresso, Dagger2 set ViemodelProvider.Factory on

Question

I have an abstract AccountRequiredActivity that looks like this (and works fine):

public abstract class AccountRequiredActivity extends LifecycleActivity {

    @Inject
    ViewModelProvider.Factory viewModelFactory;

    private AccountViewModel accountViewModel;

    public abstract void doOnCreate(Bundle savedInstanceState);
    public abstract void doOnResume();

    @Override
    protected final void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_loading_app);
        AndroidInjection.inject(this);
        accountViewModel = ViewModelProviders.of(this, viewModelFactory).get(AccountViewModel.class);

        if(!accountViewModel.isAuthenticated()) {
            redirectToLogin();
        } else {
            doOnCreate(savedInstanceState);
        };

    }

    @Override
    protected void onResume() {
        super.onResume();
        if(!accountViewModel.isAuthenticated()) {
            redirectToLogin();
        } else {
            doOnResume();
        };
    }

    private void redirectToLogin() {
        Intent intent = new Intent(this, LoginActivity.class);
        startActivity(intent);
    }

}

The problem during tests is that there is no way for me to set the viewModelFactory on the activity.

When an activity has a fragment, I can just do something like:

@Before
public void init() {
    LoginFragment fragment = LoginFragment.newInstance();
    viewModel = mock(AccountViewModel.class);
    when(viewModel.getAuthenticatedUserResource()).thenReturn(authenticatedUser);

    fragment.viewModelFactory = ViewModelUtil.createFor(viewModel);
    activityRule.getActivity().setFragment(fragment);
}

The problem however in this case is that I use this in my tests (HomeActivity extends AccountRequiredActivity):

@Rule
public ActivityTestRule<HomeActivity> activityTestRule = new ActivityTestRule<>(HomeActivity.class, true, false);

So there is no way to dynamically set the viewModelFactory, as onCreate immediately gets called. There doesn't seem to be a way to get access to the Activity object before onCreate gets called.

How to fix this problem?

Note: I use Dagger 2.11 with AndroidInjector.
Also see this question that I posted yesterday for follow-up info:

Inject ViewModelFactory.Provider in activity for espresso testing

Answer 1

I solved the problem by overriding AndroidInjector's inject() method:

@Override
public AndroidInjector<Activity> activityInjector() {
    return new AndroidInjector<Activity>() {
        @Override
        public void inject(Activity instance) {
            AccountViewModel viewModel = mock( AccountViewModel.class );
            if(instance instanceof TestHomeActivity) {
                ((TestHomeActivity) instance).viewModelFactory = ViewModelUtil.createFor( viewModel );
            }
        }
    };
} 

Answer 2

Try to override dagger module for provide ViewModelProvider.Factory.

• change testInstrumentationRunner 'com.eusecom.attendance.MockTestRunner' in app/build.gradle

• call MockYourApplication.class in MockTestRunner

• create new Mock dagger component in your MockYourApplication.class

• before run testActivity override dagger component and module

Watch example https://github.com/eurosecom/Attendance/blob/master/app/src/androidTest/java/com/eusecom/attendance/DgAeaActivityTest.java

I have not used new dagger 2.11 with AndroidInjector ( i have used older dagger2 pattern ) but may be it helps.

Answer 3

you can create own testrule

public class MyCustomRule<A extends MainActivity> extends ActivityTestRule<A> {
    public MyCustomRule(Class<A> activityClass) {
        super(activityClass);
    }

    @Override
    protected void beforeActivityLaunched() {
        super.beforeActivityLaunched();
        // Maybe prepare some mock service calls
        // Maybe override some depency injection modules with mocks
    }

    @Override
    protected Intent getActivityIntent() {
        Intent customIntent = new Intent();
        // add some custom extras and stuff
        return customIntent;
    }

    @Override
    protected void afterActivityLaunched() {
        super.afterActivityLaunched();
        // maybe you want to do something here 
    }

    @Override
    protected void afterActivityFinished() {
        super.afterActivityFinished();
        // Clean up mocks
    }
}

and set as ActivityTestRule

@Rule
public ActivityTestRule<MainActivity> testRule = new MyCustomRule<>(MainActivity.class);

in beforeActivityLaunched() you can then inject your viewModelFactory

more here

Answer 4

It’s possible to set injected activity attribute by registering a custom ActivityLifecycleCallbacks in your TestApp in the @Before Method.

Example:

 @Before
public void init(){

UserFragment fragment = UserFragment.create("foo");
viewModel = mock(UserViewModel.class);
when(viewModel.getUser()).thenReturn(userData);
when(viewModel.getRepositories()).thenReturn(repoListData);
navigationController = mock(NavigationController.class);


TestApp testApp = ((TestApp) InstrumentationRegistry.getContext().getApplicationContext());
testApp.registerActivityLifecycleCallbacks(new Application.ActivityLifecycleCallbacks() {
    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
        //will be called before the onCreate method of your activity
        activity.setViewModelFactory(ViewModelUtil.createFor(viewModel));
    }

    @Override
    public void onActivityStarted(Activity activity) {

    }

    @Override
    public void onActivityResumed(Activity activity) {

    }

    @Override
    public void onActivityPaused(Activity activity) {

    }

    @Override
    public void onActivityStopped(Activity activity) {

    }

    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {

    }

    @Override
    public void onActivityDestroyed(Activity activity) {

    }
});


fragment.viewModelFactory = ViewModelUtil.createFor(viewModel);
fragment.navigationController = navigationController;
fragment.dataBindingComponent = () -> fragmentBindingAdapters;

activityRule.getActivity().setFragment(fragment);


}