[google_sign_in] Add Android account name field as optional (#8573)

The underlying Android library for google_sign_in allows for explicitly specifying an account name, but google_sign_in doesn't have a passthrough field for this. Android clients who want to use this functionality through google_sign_in are unable. This PR would remedy this by adding a passthrough field to expose this functionality.

Flutter issue: [163257](flutter/flutter#163257)

Author: neilself

packages/google_sign_in/google_sign_in/CHANGELOG.md

@@ -1,5 +1,7 @@
-## NEXT
+## 6.3.0
 
+* Adds a sign-in field to allow Android clients to explicitly specify an account name. This
+  capability is only available within Android for the underlying libraries.
 * Updates minimum supported SDK version to Flutter 3.22/Dart 3.4.
 
 ## 6.2.2

packages/google_sign_in/google_sign_in/lib/google_sign_in.dart

@@ -187,6 +187,7 @@ class GoogleSignIn {
     this.clientId,
     this.serverClientId,
     this.forceCodeForRefreshToken = false,
+    this.forceAccountName,
   }) {
     // Start initializing.
     if (kIsWeb) {
@@ -263,6 +264,9 @@ class GoogleSignIn {
   /// Force the authorization code to be valid for a refresh token every time. Only needed on Android.
   final bool forceCodeForRefreshToken;
 
+  /// Explicitly specifies the account name to be used in sign-in. Must only be set on Android.
+  final String? forceAccountName;
+
   final StreamController<GoogleSignInAccount?> _currentUserController =
       StreamController<GoogleSignInAccount?>.broadcast();
 
@@ -317,6 +321,7 @@ class GoogleSignIn {
       clientId: clientId,
       serverClientId: serverClientId,
       forceCodeForRefreshToken: forceCodeForRefreshToken,
+      forceAccountName: forceAccountName,
     ));
 
     unawaited(GoogleSignInPlatform.instance.userDataEvents

packages/google_sign_in/google_sign_in/pubspec.yaml

@@ -3,11 +3,11 @@ description: Flutter plugin for Google Sign-In, a secure authentication system
   for signing in with a Google account.
 repository: https://github.com/flutter/packages/tree/main/packages/google_sign_in/google_sign_in
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
-version: 6.2.2
+version: 6.3.0
 
 environment:
-  sdk: ^3.4.0
-  flutter: ">=3.22.0"
+  sdk: ^3.6.0
+  flutter: ">=3.27.0"
 
 flutter:
   plugin:
@@ -24,10 +24,10 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
-  google_sign_in_android: ^6.1.0
-  google_sign_in_ios: ^5.7.0
-  google_sign_in_platform_interface: ^2.4.0
-  google_sign_in_web: ^0.12.0
+  google_sign_in_android: ^6.2.0
+  google_sign_in_ios: ^5.8.1
+  google_sign_in_platform_interface: ^2.5.0
+  google_sign_in_web: ^0.12.4+4
 
 dev_dependencies:
   build_runner: ^2.1.10

packages/google_sign_in/google_sign_in/test/google_sign_in_test.dart

@@ -113,6 +113,17 @@ void main() {
       verify(mockPlatform.signIn());
     });
 
+    test('forceAccountName sent with init method call', () async {
+      final GoogleSignIn googleSignIn =
+          GoogleSignIn(forceAccountName: '[email protected]');
+
+      await googleSignIn.signIn();
+
+      _verifyInit(mockPlatform,
+          forceAccountName: '[email protected]');
+      verify(mockPlatform.signIn());
+    });
+
     test('signOut', () async {
       final GoogleSignIn googleSignIn = GoogleSignIn();
 
@@ -447,6 +458,7 @@ void _verifyInit(
   String? clientId,
   String? serverClientId,
   bool forceCodeForRefreshToken = false,
+  String? forceAccountName,
 }) {
   verify(mockSignIn.initWithParams(argThat(
     isA<SignInInitParameters>()
@@ -479,6 +491,11 @@ void _verifyInit(
           (SignInInitParameters p) => p.forceCodeForRefreshToken,
           'forceCodeForRefreshToken',
           forceCodeForRefreshToken,
+        )
+        .having(
+          (SignInInitParameters p) => p.forceAccountName,
+          'forceAccountName',
+          forceAccountName,
         ),
   )));
 }