feat(firebase_auth): add custom auth domain setter to Firebase Auth (#12218)

Co-authored-by: russellwheatley <[email protected]>

Author: Andrey-K-Calven

packages/firebase_auth/firebase_auth/android/src/main/java/io/flutter/plugins/firebase/auth/FlutterFirebaseAuthPlugin.java

@@ -142,6 +142,11 @@ static FirebaseAuth getAuthFromPigeon(
       auth.setCustomAuthDomain(customDomain);
     }
 
+    // Auth's `getCustomAuthDomain` supersedes value from `customAuthDomain` map set by `initializeApp`
+    if (pigeonApp.getCustomAuthDomain() != null) {
+      auth.setCustomAuthDomain(pigeonApp.getCustomAuthDomain());
+    }
+
     return auth;
   }
 

packages/firebase_auth/firebase_auth/android/src/main/java/io/flutter/plugins/firebase/auth/GeneratedAndroidFirebaseAuth.java

@@ -363,6 +363,16 @@ public void setTenantId(@Nullable String setterArg) {
       this.tenantId = setterArg;
     }
 
+    private @Nullable String customAuthDomain;
+
+    public @Nullable String getCustomAuthDomain() {
+      return customAuthDomain;
+    }
+
+    public void setCustomAuthDomain(@Nullable String setterArg) {
+      this.customAuthDomain = setterArg;
+    }
+
     /** Constructor is non-public to enforce null safety; use Builder. */
     AuthPigeonFirebaseApp() {}
 
@@ -382,19 +392,28 @@ public static final class Builder {
         return this;
       }
 
+      private @Nullable String customAuthDomain;
+
+      public @NonNull Builder setCustomAuthDomain(@Nullable String setterArg) {
+        this.customAuthDomain = setterArg;
+        return this;
+      }
+
       public @NonNull AuthPigeonFirebaseApp build() {
         AuthPigeonFirebaseApp pigeonReturn = new AuthPigeonFirebaseApp();
         pigeonReturn.setAppName(appName);
         pigeonReturn.setTenantId(tenantId);
+        pigeonReturn.setCustomAuthDomain(customAuthDomain);
         return pigeonReturn;
       }
     }
 
     @NonNull
     ArrayList<Object> toList() {
-      ArrayList<Object> toListResult = new ArrayList<Object>(2);
+      ArrayList<Object> toListResult = new ArrayList<Object>(3);
       toListResult.add(appName);
       toListResult.add(tenantId);
+      toListResult.add(customAuthDomain);
       return toListResult;
     }
 
@@ -404,6 +423,8 @@ ArrayList<Object> toList() {
       pigeonResult.setAppName((String) appName);
       Object tenantId = list.get(1);
       pigeonResult.setTenantId((String) tenantId);
+      Object customAuthDomain = list.get(2);
+      pigeonResult.setCustomAuthDomain((String) customAuthDomain);
       return pigeonResult;
     }
   }

packages/firebase_auth/firebase_auth/ios/Classes/FLTFirebaseAuthPlugin.m

@@ -635,6 +635,10 @@ - (FIRAuth *_Nullable)getFIRAuthFromAppNameFromPigeon:(AuthPigeonFirebaseApp *)p
 
   auth.tenantID = pigeonApp.tenantId;
   auth.customAuthDomain = [FLTFirebaseCorePlugin getCustomDomain:app.name];
+  // Auth's `customAuthDomain` supersedes value from `getCustomDomain` set by `initializeApp`
+  if (pigeonApp.customAuthDomain != nil) {
+    auth.customAuthDomain = pigeonApp.customAuthDomain;
+  }
 
   return auth;
 }

packages/firebase_auth/firebase_auth/ios/Classes/Public/firebase_auth_messages.g.h

@@ -91,9 +91,12 @@ typedef NS_ENUM(NSUInteger, ActionCodeInfoOperation) {
 @interface AuthPigeonFirebaseApp : NSObject
 /// `init` unavailable to enforce nonnull fields, see the `make` class method.
 - (instancetype)init NS_UNAVAILABLE;
-+ (instancetype)makeWithAppName:(NSString *)appName tenantId:(nullable NSString *)tenantId;
++ (instancetype)makeWithAppName:(NSString *)appName
+                       tenantId:(nullable NSString *)tenantId
+               customAuthDomain:(nullable NSString *)customAuthDomain;
 @property(nonatomic, copy) NSString *appName;
 @property(nonatomic, copy, nullable) NSString *tenantId;
+@property(nonatomic, copy, nullable) NSString *customAuthDomain;
 @end
 
 @interface PigeonActionCodeInfoData : NSObject

packages/firebase_auth/firebase_auth/ios/Classes/firebase_auth_messages.g.m

@@ -238,17 +238,21 @@ - (NSArray *)toList {
 @end
 
 @implementation AuthPigeonFirebaseApp
-+ (instancetype)makeWithAppName:(NSString *)appName tenantId:(nullable NSString *)tenantId {
++ (instancetype)makeWithAppName:(NSString *)appName
+                       tenantId:(nullable NSString *)tenantId
+               customAuthDomain:(nullable NSString *)customAuthDomain {
   AuthPigeonFirebaseApp *pigeonResult = [[AuthPigeonFirebaseApp alloc] init];
   pigeonResult.appName = appName;
   pigeonResult.tenantId = tenantId;
+  pigeonResult.customAuthDomain = customAuthDomain;
   return pigeonResult;
 }
 + (AuthPigeonFirebaseApp *)fromList:(NSArray *)list {
   AuthPigeonFirebaseApp *pigeonResult = [[AuthPigeonFirebaseApp alloc] init];
   pigeonResult.appName = GetNullableObjectAtIndex(list, 0);
   NSAssert(pigeonResult.appName != nil, @"");
   pigeonResult.tenantId = GetNullableObjectAtIndex(list, 1);
+  pigeonResult.customAuthDomain = GetNullableObjectAtIndex(list, 2);
   return pigeonResult;
 }
 + (nullable AuthPigeonFirebaseApp *)nullableFromList:(NSArray *)list {
@@ -258,6 +262,7 @@ - (NSArray *)toList {
   return @[
     (self.appName ?: [NSNull null]),
     (self.tenantId ?: [NSNull null]),
+    (self.customAuthDomain ?: [NSNull null]),
   ];
 }
 @end

packages/firebase_auth/firebase_auth/lib/src/firebase_auth.dart

@@ -157,6 +157,35 @@ class FirebaseAuth extends FirebasePluginPlatform {
     _delegate.tenantId = tenantId;
   }
 
+  /// The current Auth instance's custom auth domain.
+  /// The auth domain used to handle redirects from OAuth provides, for example
+  /// "my-awesome-app.firebaseapp.com". By default, this is set to `null` and
+  /// default auth domain is used.
+  ///
+  /// If not `null`, this value will supersede `authDomain` property set in `initializeApp`.
+  String? get customAuthDomain {
+    return _delegate.customAuthDomain;
+  }
+
+  /// Set the current Auth instance's auth domain for apple and android platforms.
+  /// The auth domain used to handle redirects from OAuth provides, for example
+  /// "my-awesome-app.firebaseapp.com". By default, this is set to `null` and
+  /// default auth domain is used.
+  ///
+  /// If not `null`, this value will supersede `authDomain` property set in `initializeApp`.
+  set customAuthDomain(String? customAuthDomain) {
+    // Web and windows do not support setting custom auth domains on the auth instance
+    if (defaultTargetPlatform == TargetPlatform.windows || kIsWeb) {
+      final message = defaultTargetPlatform == TargetPlatform.windows
+          ? 'Cannot set custom auth domain on a FirebaseAuth instance for windows platform'
+          : 'Cannot set custom auth domain on a FirebaseAuth instance. Set the custom auth domain on `FirebaseOptions.authDomain` instance and pass into `Firebase.initializeApp()` instead.';
+      throw UnimplementedError(
+        message,
+      );
+    }
+    _delegate.customAuthDomain = customAuthDomain;
+  }
+
   /// Applies a verification code sent to the user by email or other out-of-band
   /// mechanism.
   ///

packages/firebase_auth/firebase_auth/test/firebase_auth_test.dart

@@ -10,6 +10,7 @@ import 'package:firebase_auth/firebase_auth.dart';
 import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
 import 'package:firebase_auth_platform_interface/src/method_channel/method_channel_firebase_auth.dart';
 import 'package:firebase_core/firebase_core.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/mockito.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
@@ -230,6 +231,37 @@ void main() {
       });
     });
 
+    group('customAuthDomain', () {
+      test('set customAuthDomain should call delegate method', () async {
+        // Each test uses a unique FirebaseApp instance to avoid sharing state
+        final app = await Firebase.initializeApp(
+            name: 'customAuthDomainTest',
+            options: const FirebaseOptions(
+                apiKey: 'apiKey',
+                appId: 'appId',
+                messagingSenderId: 'messagingSenderId',
+                projectId: 'projectId'));
+
+        FirebaseAuthPlatform.instance =
+            FakeFirebaseAuthPlatform(customAuthDomain: 'foo');
+        auth = FirebaseAuth.instanceFor(app: app);
+
+        expect(auth.customAuthDomain, 'foo');
+        if (defaultTargetPlatform == TargetPlatform.windows || kIsWeb) {
+          try {
+            auth.customAuthDomain = 'bar';
+          } on UnimplementedError catch (e) {
+            expect(e.message, contains('Cannot set auth domain'));
+          }
+        } else {
+          auth.customAuthDomain = 'bar';
+
+          expect(auth.customAuthDomain, 'bar');
+          expect(FirebaseAuthPlatform.instance.customAuthDomain, 'bar');
+        }
+      });
+    });
+
     group('languageCode', () {
       test('.languageCode should call delegate method', () {
         auth.languageCode;
@@ -1026,11 +1058,14 @@ class MockFirebaseAuth extends Mock
 class FakeFirebaseAuthPlatform extends Fake
     with MockPlatformInterfaceMixin
     implements FirebaseAuthPlatform {
-  FakeFirebaseAuthPlatform({this.tenantId});
+  FakeFirebaseAuthPlatform({this.tenantId, this.customAuthDomain});
 
   @override
   String? tenantId;
 
+  @override
+  String? customAuthDomain;
+
   @override
   FirebaseAuthPlatform delegateFor(
       {required FirebaseApp app, Persistence? persistence}) {

packages/firebase_auth/firebase_auth/windows/messages.g.cpp

@@ -200,11 +200,15 @@ PigeonMultiFactorInfo PigeonMultiFactorInfo::FromEncodableList(
 AuthPigeonFirebaseApp::AuthPigeonFirebaseApp(const std::string& app_name)
     : app_name_(app_name) {}
 
-AuthPigeonFirebaseApp::AuthPigeonFirebaseApp(const std::string& app_name,
-                                             const std::string* tenant_id)
+AuthPigeonFirebaseApp::AuthPigeonFirebaseApp(
+    const std::string& app_name, const std::string* tenant_id,
+    const std::string* custom_auth_domain)
     : app_name_(app_name),
       tenant_id_(tenant_id ? std::optional<std::string>(*tenant_id)
-                           : std::nullopt) {}
+                           : std::nullopt),
+      custom_auth_domain_(custom_auth_domain
+                              ? std::optional<std::string>(*custom_auth_domain)
+                              : std::nullopt) {}
 
 const std::string& AuthPigeonFirebaseApp::app_name() const { return app_name_; }
 
@@ -225,11 +229,27 @@ void AuthPigeonFirebaseApp::set_tenant_id(std::string_view value_arg) {
   tenant_id_ = value_arg;
 }
 
+const std::string* AuthPigeonFirebaseApp::custom_auth_domain() const {
+  return custom_auth_domain_ ? &(*custom_auth_domain_) : nullptr;
+}
+
+void AuthPigeonFirebaseApp::set_custom_auth_domain(
+    const std::string_view* value_arg) {
+  custom_auth_domain_ =
+      value_arg ? std::optional<std::string>(*value_arg) : std::nullopt;
+}
+
+void AuthPigeonFirebaseApp::set_custom_auth_domain(std::string_view value_arg) {
+  custom_auth_domain_ = value_arg;
+}
+
 EncodableList AuthPigeonFirebaseApp::ToEncodableList() const {
   EncodableList list;
-  list.reserve(2);
+  list.reserve(3);
   list.push_back(EncodableValue(app_name_));
   list.push_back(tenant_id_ ? EncodableValue(*tenant_id_) : EncodableValue());
+  list.push_back(custom_auth_domain_ ? EncodableValue(*custom_auth_domain_)
+                                     : EncodableValue());
   return list;
 }
 
@@ -240,6 +260,11 @@ AuthPigeonFirebaseApp AuthPigeonFirebaseApp::FromEncodableList(
   if (!encodable_tenant_id.IsNull()) {
     decoded.set_tenant_id(std::get<std::string>(encodable_tenant_id));
   }
+  auto& encodable_custom_auth_domain = list[2];
+  if (!encodable_custom_auth_domain.IsNull()) {
+    decoded.set_custom_auth_domain(
+        std::get<std::string>(encodable_custom_auth_domain));
+  }
   return decoded;
 }
 

packages/firebase_auth/firebase_auth/windows/messages.g.h

@@ -213,7 +213,8 @@ class AuthPigeonFirebaseApp {
 
   // Constructs an object setting all fields.
   explicit AuthPigeonFirebaseApp(const std::string& app_name,
-                                 const std::string* tenant_id);
+                                 const std::string* tenant_id,
+                                 const std::string* custom_auth_domain);
 
   const std::string& app_name() const;
   void set_app_name(std::string_view value_arg);
@@ -222,6 +223,10 @@ class AuthPigeonFirebaseApp {
   void set_tenant_id(const std::string_view* value_arg);
   void set_tenant_id(std::string_view value_arg);
 
+  const std::string* custom_auth_domain() const;
+  void set_custom_auth_domain(const std::string_view* value_arg);
+  void set_custom_auth_domain(std::string_view value_arg);
+
  private:
   static AuthPigeonFirebaseApp FromEncodableList(
       const flutter::EncodableList& list);
@@ -242,6 +247,7 @@ class AuthPigeonFirebaseApp {
   friend class GenerateInterfacesCodecSerializer;
   std::string app_name_;
   std::optional<std::string> tenant_id_;
+  std::optional<std::string> custom_auth_domain_;
 };
 
 // Generated class from Pigeon that represents data sent in messages.
@@ -535,6 +541,7 @@ class PigeonUserDetails {
 
   const flutter::EncodableList& provider_data() const;
   void set_provider_data(const flutter::EncodableList& value_arg);
+
   static PigeonUserDetails FromEncodableList(
       const flutter::EncodableList& list);
   flutter::EncodableList ToEncodableList() const;

packages/firebase_auth/firebase_auth_platform_interface/lib/src/method_channel/method_channel_firebase_auth.dart

@@ -62,6 +62,7 @@ class MethodChannelFirebaseAuth extends FirebaseAuthPlatform {
     return AuthPigeonFirebaseApp(
       appName: app.name,
       tenantId: tenantId,
+      customAuthDomain: customAuthDomain,
     );
   }
 

packages/firebase_auth/firebase_auth_platform_interface/lib/src/method_channel/method_channel_multi_factor.dart

@@ -19,6 +19,7 @@ class MethodChannelMultiFactor extends MultiFactorPlatform {
     return AuthPigeonFirebaseApp(
       appName: auth.app.name,
       tenantId: auth.tenantId,
+      customAuthDomain: auth.customAuthDomain,
     );
   }
 

packages/firebase_auth/firebase_auth_platform_interface/lib/src/method_channel/method_channel_user.dart

@@ -25,6 +25,7 @@ class MethodChannelUser extends UserPlatform {
     return AuthPigeonFirebaseApp(
       appName: auth.app.name,
       tenantId: auth.tenantId,
+      customAuthDomain: auth.customAuthDomain,
     );
   }
 

packages/firebase_auth/firebase_auth_platform_interface/lib/src/pigeon/messages.pigeon.dart

@@ -128,16 +128,20 @@ class AuthPigeonFirebaseApp {
   AuthPigeonFirebaseApp({
     required this.appName,
     this.tenantId,
+    this.customAuthDomain,
   });
 
   String appName;
 
   String? tenantId;
 
+  String? customAuthDomain;
+
   Object encode() {
     return <Object?>[
       appName,
       tenantId,
+      customAuthDomain,
     ];
   }
 
@@ -146,6 +150,7 @@ class AuthPigeonFirebaseApp {
     return AuthPigeonFirebaseApp(
       appName: result[0]! as String,
       tenantId: result[1] as String?,
+      customAuthDomain: result[2] as String?,
     );
   }
 }

packages/firebase_auth/firebase_auth_platform_interface/lib/src/platform_interface/platform_interface_firebase_auth.dart

@@ -33,6 +33,14 @@ abstract class FirebaseAuthPlatform extends PlatformInterface {
   /// parent project. By default, this is set to `null`.
   String? tenantId;
 
+  /// Set the current Auth instance's auth domain for apple and android platforms.
+  /// The auth domain used to handle redirects from OAuth provides, for example
+  /// "my-awesome-app.firebaseapp.com". By default, this is set to `null` and
+  /// default auth domain is used.
+  ///
+  /// If not `null`, this value will supersede `authDomain` property set in `initializeApp`.
+  String? customAuthDomain;
+
   /// Create an instance using [app]
   FirebaseAuthPlatform({this.appInstance}) : super(token: _token);
 

packages/firebase_auth/firebase_auth_platform_interface/pigeons/messages.dart

@@ -66,10 +66,12 @@ class AuthPigeonFirebaseApp {
   const AuthPigeonFirebaseApp({
     required this.appName,
     required this.tenantId,
+    required this.customAuthDomain,
   });
 
   final String appName;
   final String? tenantId;
+  final String? customAuthDomain;
 }
 
 /// The type of operation that generated the action code from calling