How to mock the FirebaseApp in flutter

Question

I am trying to test a method that uses FirebaseFirestore but I am not able to mock the FirebaseFirestore.instance property.

I am following these examples:

1. In

Answer 1

I had the same problem. Using this answer I found the solution.

1. Copy the contents of: https://github.com/FirebaseExtended/flutterfire/blob/master/packages/firebase_auth/firebase_auth/test/mock.dart into a file, that you can import into your tests, where you need to initialize a Firebase app.

2. Call setupFirebaseAuthMocks(); at the top of your main function for all your tests.

3. In your setUpAll function, call await Firebase.initializeApp(); (You can also put this in your main function under setupFirebaseAuthMocks(); will still work).

Now you should have a mocked Firebase app.

Here is a full example:

import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter_test/flutter_test.dart';
import '../lib/authentication/your_auth_using_firebase.dart';
import './mock.dart'; // from: https://github.com/FirebaseExtended/flutterfire/blob/master/packages/firebase_auth/firebase_auth/test/mock.dart



void main() {
  // TestWidgetsFlutterBinding.ensureInitialized(); Gets called in setupFirebaseAuthMocks()
  setupFirebaseAuthMocks();

  setUpAll(() async {
    await Firebase.initializeApp();
  });

  testWidgets('Your Test', (WidgetTester tester) async {
    final YourFirebaseAuthClass authService = YourFirebaseAuthClass();
    // Tests to write
  });
}