JUnit testing on class with firebase

Question

I\'m trying to JUnit test this class:

public class WeekListActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
         


        

Answer 1

As usual, I suggest everybody to not mix presentation and storage code. And this is a question for another topic.

And here the trick how you can achieve what you want. First, extract method for Firebase initialisation and providing FirebaseAuth:

 @VisibleForTest
 @NonNull
 FirebaseAuth initAndReturnFirebaseAuth() {
     FirebaseApp.initializeApp(this);
     FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
 }

Second, create test activity and override this method:

public class TestWeekListActivity extends WeekListActivity {
    @Override
    @NonNull
    FirebaseAuth initAndReturnFirebaseAuth() {
       FirebaseAuth authMock = mock(FirebaseAuth.class);
       when(authMock.getCurrentUser()).thenReturn(mockFirebaseUser);
       return authMock;
    }
}

And then use test activity in test instead of you real activity.

Hope it helps!