How to unit test a ViewModel that extends AndroidViewModel. Having issues with the application in the constructor

Question

So I'm having to write unit tests and I need to test my ViewModels.

I have a base ViewModel and that BaseViewModel extends AndroidViewModel. The reason I extend AndroidViewModel is so that I can use the context for Dagger.

My BaseViewModel.

public class BaseViewModel extends AndroidViewModel {

protected @Inject SharedPreferencesHelper sharedPreferencesHelper;

public BaseViewModel(@NonNull Application application) {
    super(application);

    //Only inject sharedPreferences since it is used in almost all of the VMs.
    ((CommissioningApplication) getApplication()).getAppComponent().inject(this);
}

}

Essentially I'm having issues creating an instance of my ViewModel in my unit tests. I have tried many things and have been unsuccessful.

I have considered extending ViewModel instead of AndroidViewModel and creating a Factory that will pass the application context to my ViewModels. But in the end I will run towards the same issue whenever I try to create an instance of my ViewModel.

Does anyone have an example that I could follow on how to test this? Or would have I have to do Instrumented testing instead of Unit testing?

I'm very new to testing so maybe I'm not doing things properly, any help would be great.

Thanks

Answer 1

As stated here:

Mockito.mock(Application::class.java)