$ brew install flutter

import UIKit
import Flutter
+ import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
+     FirebaseApp.configure()
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

import UIKit
import Flutter
import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
+    if (Firebase.apps.isEmpty) {
        FirebaseApp.configure()
+    }
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

# Uncomment this line to define a global platform for your project
- # platform :ios, '9.0'
+ platform :ios, '10.6'
...
+ pod 'Firebase/Analytics'
+ pod 'Firebase/Auth'
+ pod 'Firebase/Firestore'

<?xml version="1.0" encoding="UTF-8"?>
...
<dict>
...
<key>CFBundleURLTypes</key>
<array>
	<dict>
		<key>CFBundleTypeRole</key>
		<string>Editor</string>
		<key>CFBundleURLSchemes</key>
		<array>
			<string>{GoogleService-Info.plist の REVERSED_CLIENT_IDを入れる}</string>
		</array>
	</dict>
</array>
...
</dict>
</plist>

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  if (Firebase.apps.isEmpty) {
    await Firebase.initializeApp(
      options: DefaultFirebaseOptions.currentPlatform,
    );
  }
  runApp(const App());
}

Widget build(BuildContext context) {
  return MaterialApp(
...
    initialRoute:
        FirebaseAuth.instance.currentUser == null ? '/sign-in' : '/',
    routes: {
      '/sign-in': (context) => SignInScreen(
            actions: [
              AuthStateChangeAction<SignedIn>((context, _) {
                Navigator.of(context).pushReplacementNamed('/');
              }),
            ],
            providerConfigs: providerConfigs,
          ),
      '/': (context) => const Tabs()
    },
...
} 

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  if (Firebase.apps.isEmpty) {
    await Firebase.initializeApp(
      name: 'Hoge',
      options: DefaultFirebaseOptions.currentPlatform,
    );
  }
  runApp(const App());
}

flutter build ios

flutter devices

flutter install -d [ここ頭文字]

✓ Successfully generated launcher icons
Unhandled exception:
FormatException: Invalid number (at character 1)

^

#0      int._handleFormatError (dart:core-patch/integers_patch.dart:129:7)
...

  flutter_launcher_icons:
    git:
      url: https://github.com/Davenchy/flutter_launcher_icons.git
      ref: fixMinSdkParseFlutter2.8

  ════════════════════════════════════════════
     FLUTTER LAUNCHER ICONS (v0.9.1)                               
  ════════════════════════════════════════════
  
• Creating default icons Android
• Adding a new Android launcher icon
• Overwriting default iOS launcher icon with new icon

✓ Successfully generated launcher icons

Guideline 5.1.1 - Legal - Privacy - Data Collection and Storage


We noticed that your app requires users to register or log in to access features that are not account based.

Apps may not require users to enter personal information to function, except when directly relevant to the core functionality of the app or required by law. For example, an e-commerce app should let users browse store offerings and other features that are not account based before being asked to register, or a restaurant app should allow users to explore the menu before placing an order. Registration must then only be required for account-specific features, such as saving items for future reference or placing an order.

Next Steps

To resolve this issue, please revise your app to let users freely access your app’s features that are not account based. 

Resources 

See guideline 5.1.1(v) - Account Sign-In to learn more about our requirements for apps with account-based content and features.

await FirebaseAuth.instance.signInAnonymously();

FirebaseAuthException ([firebase_auth/admin-restricted-operation] ADMIN_ONLY_OPERATION)