How to share Flutter source code for projects linked to Firebase? - flutter

Question

I have a Flutter project linked to my Firebase account (using FlutterFire CLI).
Now that I finished the project I want to sell the source code.
How can I change the Firebase account linked to this project?
When using FlutterFire CLI, it generates a file called firebase_options.dart containing Firebase options for each platform like this:
static const FirebaseOptions android = FirebaseOptions(
apiKey: '-------',
appId: '------',
messagingSenderId: '-----',
projectId: '----------',
storageBucket: '--------',
  );
Do I have just to change these values? If yes, where can I find all of them?
main.dart
import 'firebase_options.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);
runApp(const MyApp());
}
Full firebase_options.dart file
// File generated by FlutterFire CLI.
// ignore_for_file: lines_longer_than_80_chars, avoid_classes_with_only_static_members
import 'package:firebase_core/firebase_core.dart' show FirebaseOptions;
import 'package:flutter/foundation.dart'
show defaultTargetPlatform, kIsWeb, TargetPlatform;
/// Default [FirebaseOptions] for use with your Firebase apps.
///
/// Example:
/// ```dart
/// import 'firebase_options.dart';
/// // ...
/// await Firebase.initializeApp(
/// options: DefaultFirebaseOptions.currentPlatform,
/// );
/// ```
class DefaultFirebaseOptions {
static FirebaseOptions get currentPlatform {
if (kIsWeb) {
return web;
}
switch (defaultTargetPlatform) {
case TargetPlatform.android:
return android;
case TargetPlatform.iOS:
throw UnsupportedError(
'DefaultFirebaseOptions have not been configured for ios - '
'you can reconfigure this by running the FlutterFire CLI again.',
);
case TargetPlatform.macOS:
throw UnsupportedError(
'DefaultFirebaseOptions have not been configured for macos - '
'you can reconfigure this by running the FlutterFire CLI again.',
);
case TargetPlatform.windows:
throw UnsupportedError(
'DefaultFirebaseOptions have not been configured for windows - '
'you can reconfigure this by running the FlutterFire CLI again.',
);
case TargetPlatform.linux:
throw UnsupportedError(
'DefaultFirebaseOptions have not been configured for linux - '
'you can reconfigure this by running the FlutterFire CLI again.',
);
default:
throw UnsupportedError(
'DefaultFirebaseOptions are not supported for this platform.',
);
}
}
static const FirebaseOptions web = FirebaseOptions(
apiKey: '------',
appId: '------',
messagingSenderId: '-----',
projectId: '------',
authDomain: '--------',
storageBucket: '--------',
measurementId: '--------',
);
static const FirebaseOptions android = FirebaseOptions(
apiKey: '----',
appId: '----',
messagingSenderId: '--------',
projectId: '------',
storageBucket: '--------',
);
}
I tried to change the values (in firebase_options.dart) and that caused this error:
E/flutter (26545): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: [core/duplicate-app] A Firebase App named "[DEFAULT]" already exists
it throws this error(duplicateApp from method_channel_firebase.dart):
// If there is a native default app and the user provided options do a soft
// check to see if options are roughly identical (so we don't unnecessarily
// throw on minor differences such as platform specific keys missing
// e.g. hot reloads/restarts).
if (defaultApp != null && _options != null) {
if (_options.apiKey != defaultApp.options.apiKey ||
(_options.databaseURL != null &&
_options.databaseURL != defaultApp.options.databaseURL) ||
(_options.storageBucket != null &&
_options.storageBucket != defaultApp.options.storageBucket)) {
// Options are different; throw.
throw duplicateApp(defaultFirebaseAppName);
}
// Options are roughly the same; so we'll return the existing app.
}

Answer 1

You can change the firebase account linked to this project. This error that you are seeing
E/flutter (26545): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: [core/duplicate-app] A Firebase App named "[DEFAULT]" already exists
is caused by the original gradle sync operation generating a Google-Services.json file and using it within the app. To remove this error, switch into the android folder from your main flutter project and run
./gradlew clean
This command calls the gradle wrapper which then cleans the project and brings it back to its original state. The flutter team uses a default empty flutter_options.dart file for their projects. You may want to consider doing that if you are seeing the source code to someone. I would just package instructions for how to configure their project to work with a new Firebase project that they would select.