Flutter: Firebase has not been correctly initialized - firebase

Question

I'm working on iPhone 12 Pro Max Emulator, macOS Catalina.
I'm getting this error when I try to run the app:
[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: [core/not-initialized] Firebase has not been correctly initialized.
Also there is a tip in the console:
Usually this means you've attempted to use a Firebase service before calling Firebase.initializeApp.
I initialize the Firebase before use it. Like this:
void main() async {
print('-- main');
WidgetsFlutterBinding.ensureInitialized();
print('-- WidgetsFlutterBinding.ensureInitialized');
await Firebase.initializeApp();
print('-- main: Firebase.initializeApp');
runApp(const MyApp());
}
This is what I see in the console output:
Xcode build done. 132.9s
flutter: -- main
flutter: -- WidgetsFlutterBinding.ensureInitialized
[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: [core/not-initialized] Firebase has not been correctly initialized.
Usually this means you've attempted to use a Firebase service before calling `Firebase.initializeApp`.
I can't see the -- main: Firebase.initializeApp line in the console. So it fails in first trying to initialize the Firebase.
I create Android/Apple apps in Firebase. Downloaded google-services.json / GoogleService-Info.plist and put in the project.
GoogleService-Info.plist:
google-services.json:
I'm not using the android, but I added dependency into build.gradle: classpath 'com.google.gms:google-services:4.3.10'
And app/build.gradle: apply plugin: 'com.google.gms.google-services'
dependencies:
firebase_auth: ^3.3.5
firebase_messaging: ^10.0.9
google_sign_in: ^5.2.1
flutter --version:
Flutter 2.5.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 18116933e7 (3 months ago) • 2021-10-15 10:46:35 -0700
Engine • revision d3ea636dc5
Tools • Dart 2.14.4
How can I solve this problem? BTW, I'm working on a brand new flutter project.

Answer 1

When you add google-services.json to an iOS project, you need to add it using Xcode as described in the following document:
https://firebase.flutter.dev/docs/manual-installation/ios
If you read through the page, you'll find the following note:
adding [google-service.json] manually via the filesystem won't link the file to the project
You need to try that then restart your app (rebuild it).
Edit: Additional Note:
You'll also need to add firebase_core to your dependencies in pubspec.yaml.

Answer 2

You have to add the GoogleService-Info.plist in Xcode instead of just placing it into the folder:
So it looks like this:
Note: The file can also be moved to a sub folder in the project (i.e. Runner).
Source: https://www.kindacode.com/article/flutter-correctly-adding-googleservices-info-plist-to-ios/

Answer 3

Here's how I fixed this error:
Ensure that all firebase services have been added to your pubspec.yaml file, in the dependencies section. firebase_core appears to be missing and is required to connect your flutter app to your firebase project.
You can simply add it using this command:
flutter pub add firebase_core
Add the firebase plugins to your main file:
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';
Replace your void main function with an asynchronous one:
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
runApp(const YourAppGoesHere());
}

Answer 4

When I add the GoogleService-Info.plist file in Xcode, I used the wrong name GoogleService-Info**(1)**.plist.
If you have the same file in downloads, mac adds a number of copy to the next downloaded file.