🐛 [cloud_firestore] Need working example for Firestore Emulator in Widget tests - initializeApp hangs indefinitely

[normidar]

What feature would you like to see?

Issue Description

When trying to use the Firestore Emulator in Widget tests (testWidgets), Firebase.initializeApp() hangs indefinitely. We need a working example of how to properly set up and use the Firestore Emulator in Widget tests.

Current Code

testWidgets('test emulate', (tester) async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: const FirebaseOptions(
        apiKey: 'fake-api-key',
        appId: 'fake-app-id',
        messagingSenderId: 'fake-sender-id',
        projectId: 'demo-project',
      ),
    );
    FirebaseFirestore.instance.settings = const Settings(
      host: 'localhost:8085',
      sslEnabled: false,
      persistenceEnabled: false,
  );
});

Why This Matters

Fake Firestore don't support all Firestore features. Having the ability to test with the actual Firestore Emulator would allow us to:

1. Test with real Firestore behavior
2. Use features not available in fake implementations
3. Have more confidence in our tests

What I'm Looking For

1. A working example of how to properly set up the Firestore Emulator in Widget tests
2. If this is not currently possible, guidance on what needs to be implemented to make it possible

Environment

• firebase_core version: 3.4.0
• cloud_firestore version: 5.5.0
• Platform: Mac OS M1 chip
• Flutter version:

Flutter 3.24.4 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 603104015d (4 weeks ago) • 2024-10-24 08:01:25 -0700
Engine • revision db49896cf2
Tools • Dart 3.5.4 • DevTools 2.37.3

[SelaseKay]

Hi @normidar, thanks for raising this concern. However, I don't think this is the right way to go about it. Can you try something like this to see if it resolves your issue:

void main() {
  setUpAll(() async {
    WidgetsFlutterBinding.ensureInitialized();
    
    await Firebase.initializeApp(
      options: const FirebaseOptions(
        apiKey: 'fake-api-key',
        appId: 'fake-app-id',
        messagingSenderId: 'fake-sender-id',
        projectId: 'demo-project',
      ),
    );
    
    FirebaseFirestore.instance.useFirestoreEmulator('localhost', 8085);
  });


  testWidgets('some firestore test', (WidgetTester tester) async {
    // Test logic here, Firebase is already initialized
  });
}

[normidar]

Thank you for your response.

Is it okay to use dummy values like 'fake-api-key' in the test environment, or do I need to use real Firebase credentials?

[normidar]

I ran that and got an error:

PlatformException(channel-error, Unable to establish connection on channel., null, null)
package:firebase_core_platform_interface/src/pigeon/messages.pigeon.dart 210:7  FirebaseCoreHostApi.initializeCore

[SelaseKay]

You'll have to use your real Firebase credentials. Did you start your firebase emulator before running the test?

[russellwheatley]

@normidar - we have firestore test setup in the repository that you can follow. https://github.com/firebase/flutterfire/blob/main/packages/cloud_firestore/cloud_firestore/example/integration_test/e2e_test.dart

Pay attention to test_driver/ and integration_test directory setup.

Here is how to run: https://github.com/firebase/flutterfire/blob/main/.github/workflows/android.yaml#L90

As @SelaseKay mentioned - run firebase emualtors.