[google_sign_in_platform_interface] Add support for serverClientId

Author: blaugold

packages/google_sign_in/google_sign_in_platform_interface/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 2.2.0
+
+* Add `GoogleSignInPlatform.init2` and deprecate `GoogleSignInPlatform.init` to support the
+  `serverClientId` parameter.
+
 ## 2.1.2
 
 * Internal code cleanup for stricter analysis options.

packages/google_sign_in/google_sign_in_platform_interface/lib/google_sign_in_platform_interface.dart

@@ -66,6 +66,9 @@ abstract class GoogleSignInPlatform {
   /// Initializes the plugin. You must call this method before calling other
   /// methods.
   ///
+  /// This method is deprecated and will be removed in the future.
+  /// Use [init2] instead.
+  ///
   /// The [hostedDomain] argument specifies a hosted domain restriction. By
   /// setting this, sign in will be restricted to accounts of the user in the
   /// specified domain. By default, the list of accounts will not be restricted.
@@ -89,6 +92,38 @@ abstract class GoogleSignInPlatform {
     throw UnimplementedError('init() has not been implemented.');
   }
 
+  /// Initializes the plugin. You must call this method before calling other
+  /// methods.
+  ///
+  /// The [hostedDomain] argument specifies a hosted domain restriction. By
+  /// setting this, sign in will be restricted to accounts of the user in the
+  /// specified domain. By default, the list of accounts will not be restricted.
+  ///
+  /// The list of [scopes] are OAuth scope codes to request when signing in.
+  /// These scope codes will determine the level of data access that is granted
+  /// to your application by the user. The full list of available scopes can be
+  /// found here: <https://developers.google.com/identity/protocols/googlescopes>
+  ///
+  /// The [signInOption] determines the user experience. [SigninOption.games] is
+  /// only supported on Android.
+  ///
+  /// See:
+  /// https://developers.google.com/identity/sign-in/web/reference#gapiauth2initparams
+  Future<void> init2({
+    List<String> scopes = const <String>[],
+    SignInOption signInOption = SignInOption.standard,
+    String? hostedDomain,
+    String? clientId,
+    String? serverClientId,
+  }) async {
+    return init(
+      scopes: scopes,
+      signInOption: signInOption,
+      hostedDomain: hostedDomain,
+      clientId: clientId,
+    );
+  }
+
   /// Attempts to reuse pre-existing credentials to sign in again, without user interaction.
   Future<GoogleSignInUserData?> signInSilently() async {
     throw UnimplementedError('signInSilently() has not been implemented.');

packages/google_sign_in/google_sign_in_platform_interface/lib/src/method_channel_google_sign_in.dart

@@ -25,12 +25,29 @@ class MethodChannelGoogleSignIn extends GoogleSignInPlatform {
     SignInOption signInOption = SignInOption.standard,
     String? hostedDomain,
     String? clientId,
+  }) {
+    return init2(
+      scopes: scopes,
+      signInOption: signInOption,
+      hostedDomain: hostedDomain,
+      clientId: clientId,
+    );
+  }
+
+  @override
+  Future<void> init2({
+    List<String> scopes = const <String>[],
+    SignInOption signInOption = SignInOption.standard,
+    String? hostedDomain,
+    String? clientId,
+    String? serverClientId,
   }) {
     return channel.invokeMethod<void>('init', <String, dynamic>{
       'signInOption': signInOption.toString(),
       'scopes': scopes,
       'hostedDomain': hostedDomain,
       'clientId': clientId,
+      'serverClientId': serverClientId,
     });
   }
 

packages/google_sign_in/google_sign_in_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/plugins/tree/main/packages/google_sign_in
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 2.1.2
+version: 2.2.0
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

packages/google_sign_in/google_sign_in_platform_interface/test/method_channel_google_sign_in_test.dart

@@ -108,6 +108,21 @@ void main() {
           'scopes': <String>['two', 'scopes'],
           'signInOption': 'SignInOption.games',
           'clientId': 'fakeClientId',
+          'serverClientId': null,
+        }),
+        () {
+          googleSignIn.init2(
+              hostedDomain: 'example.com',
+              scopes: <String>['two', 'scopes'],
+              signInOption: SignInOption.games,
+              clientId: 'fakeClientId',
+              serverClientId: 'fakeServerClientId');
+        }: isMethodCall('init', arguments: <String, dynamic>{
+          'hostedDomain': 'example.com',
+          'scopes': <String>['two', 'scopes'],
+          'signInOption': 'SignInOption.games',
+          'clientId': 'fakeClientId',
+          'serverClientId': 'fakeServerClientId',
         }),
         () {
           googleSignIn.getTokens(