feat(auth, web): add phone mfa

packages/firebase_auth/firebase_auth/example/lib/auth.dart

@@ -2,7 +2,6 @@ import 'dart:io';
 
 import 'package:firebase_auth/firebase_auth.dart';
 import 'package:firebase_auth_example/config.dart';
-import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';

packages/firebase_auth/firebase_auth/example/lib/profile.dart

@@ -1,7 +1,6 @@
 import 'dart:developer';
 
 import 'package:firebase_auth/firebase_auth.dart';
-import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
 import 'package:flutter/material.dart';
 import 'package:google_sign_in/google_sign_in.dart';
 

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

@@ -607,7 +607,7 @@ class FirebaseAuth extends FirebasePluginPlatform {
     // If we add a recaptcha to the page by creating a new instance, we must
     // also clear that instance before proceeding.
     bool mustClear = verifier == null;
-    verifier ??= RecaptchaVerifier();
+    verifier ??= RecaptchaVerifier(auth: _delegate);
     final result =
         await _delegate.signInWithPhoneNumber(phoneNumber, verifier.delegate);
     if (mustClear) {

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

@@ -17,7 +17,7 @@ class MultiFactor {
   ///
   /// [displayName] can be used to provide a display name for the second factor.
   Future<void> enroll(
-    MultiFactorAssertion assertion, {
+    MultiFactorAssertionPlatform assertion, {
     String? displayName,
   }) async {
     return _delegate.enroll(assertion, displayName: displayName);
@@ -40,3 +40,14 @@ class MultiFactor {
     return _delegate.getEnrolledFactors();
   }
 }
+
+/// Provider for generating a PhoneMultiFactorAssertion.
+class PhoneMultiFactorGenerator {
+  /// Transforms a PhoneAuthCredential into a [MultiFactorAssertion]
+  /// which can be used to confirm ownership of a phone second factor.
+  static MultiFactorAssertionPlatform getAssertion(
+    PhoneAuthCredential credential,
+  ) {
+    return PhoneMultiFactorGeneratorPlatform.instance.getAssertion(credential);
+  }
+}

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

@@ -46,6 +46,7 @@ class RecaptchaVerifier {
   ///
   /// [onExpired] An optional callback which is called when the reCAPTCHA expires.
   factory RecaptchaVerifier({
+    required FirebaseAuthPlatform auth,
     String? container,
     RecaptchaVerifierSize size = RecaptchaVerifierSize.normal,
     RecaptchaVerifierTheme theme = RecaptchaVerifierTheme.light,
@@ -55,6 +56,7 @@ class RecaptchaVerifier {
   }) {
     return RecaptchaVerifier._(
       _factory.delegateFor(
+        auth: auth,
         container: container,
         size: size,
         theme: theme,

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

@@ -262,7 +262,7 @@ class User {
     // If we add a recaptcha to the page by creating a new instance, we must
     // also clear that instance before proceeding.
     bool mustClear = verifier == null;
-    verifier ??= RecaptchaVerifier();
+    verifier ??= RecaptchaVerifier(auth: _delegate.auth);
     final result =
         await _delegate.linkWithPhoneNumber(phoneNumber, verifier.delegate);
     if (mustClear) {

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

@@ -18,11 +18,13 @@ class MethodChannelMultiFactor extends MultiFactorPlatform {
 
   @override
   Future<void> enroll(
-    MultiFactorAssertion assertion, {
+    MultiFactorAssertionPlatform assertion, {
     String? displayName,
   }) async {
-    if (assertion.credential is PhoneAuthCredential) {
-      final credential = assertion.credential as PhoneAuthCredential;
+    final _assertion = assertion as MultiFactorAssertion;
+
+    if (_assertion.credential is PhoneAuthCredential) {
+      final credential = _assertion.credential as PhoneAuthCredential;
       final verificationId = credential.verificationId;
       final verificationCode = credential.smsCode;
 
@@ -43,7 +45,7 @@ class MethodChannelMultiFactor extends MultiFactorPlatform {
       );
     } else {
       throw UnimplementedError(
-        'Credential type ${assertion.credential} is not supported yet',
+        'Credential type ${_assertion.credential} is not supported yet',
       );
     }
   }
@@ -90,10 +92,12 @@ class MethodChannelMultiFactorResolver extends MultiFactorResolverPlatform {
 
   @override
   Future<UserCredentialPlatform> resolveSignIn(
-    MultiFactorAssertion assertion,
+    MultiFactorAssertionPlatform assertion,
   ) async {
-    if (assertion.credential is PhoneAuthCredential) {
-      final credential = assertion.credential as PhoneAuthCredential;
+    final _assertion = assertion as MultiFactorAssertion;
+
+    if (_assertion.credential is PhoneAuthCredential) {
+      final credential = _assertion.credential as PhoneAuthCredential;
       final verificationId = credential.verificationId;
       final verificationCode = credential.smsCode;
 
@@ -118,8 +122,30 @@ class MethodChannelMultiFactorResolver extends MultiFactorResolverPlatform {
       return userCredential;
     } else {
       throw UnimplementedError(
-        'Credential type ${assertion.credential} is not supported yet',
+        'Credential type ${_assertion.credential} is not supported yet',
       );
     }
   }
 }
+
+/// Represents an assertion that the Firebase Authentication server
+/// can use to authenticate a user as part of a multi-factor flow.
+class MultiFactorAssertion extends MultiFactorAssertionPlatform {
+  MultiFactorAssertion(this.credential) : super();
+
+  /// Associated credential to the assertion
+  final AuthCredential credential;
+}
+
+/// Helper class used to generate PhoneMultiFactorAssertions.
+class MethodChannelPhoneMultiFactorGenerator
+    extends PhoneMultiFactorGeneratorPlatform {
+  /// Transforms a PhoneAuthCredential into a [MultiFactorAssertion]
+  /// which can be used to confirm ownership of a phone second factor.
+  @override
+  MultiFactorAssertionPlatform getAssertion(
+    PhoneAuthCredential credential,
+  ) {
+    return MultiFactorAssertion(credential);
+  }
+}

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

@@ -1,4 +1,5 @@
 import 'package:firebase_auth_platform_interface/firebase_auth_platform_interface.dart';
+import 'package:firebase_auth_platform_interface/src/method_channel/method_channel_multi_factor.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
 /// {@template .platformInterfaceMultiFactor}
@@ -19,7 +20,10 @@ abstract class MultiFactorPlatform extends PlatformInterface {
   /// Enrolls a second factor as identified by the [MultiFactorAssertion] parameter for the current user.
   ///
   /// [displayName] can be used to provide a display name for the second factor.
-  Future<void> enroll(MultiFactorAssertion assertion, {String? displayName}) {
+  Future<void> enroll(
+    MultiFactorAssertionPlatform assertion, {
+    String? displayName,
+  }) {
     throw UnimplementedError('enroll() is not implemented');
   }
 
@@ -54,21 +58,7 @@ class MultiFactorSession {
 
 /// Represents an assertion that the Firebase Authentication server
 /// can use to authenticate a user as part of a multi-factor flow.
-class MultiFactorAssertion {
-  const MultiFactorAssertion._(this.credential);
-
-  /// Associated credential to the assertion
-  final AuthCredential credential;
-}
-
-/// Helper class used to generate PhoneMultiFactorAssertions.
-class PhoneMultiFactorGenerator {
-  /// Transforms a PhoneAuthCredential into a [MultiFactorAssertion]
-  /// which can be used to confirm ownership of a phone second factor.
-  static MultiFactorAssertion getAssertion(PhoneAuthCredential credential) {
-    return MultiFactorAssertion._(credential);
-  }
-}
+class MultiFactorAssertionPlatform {}
 
 /// {@macro .platformInterfaceMultiFactorResolverPlatform}
 /// Utility class that contains methods to resolve second factor
@@ -91,7 +81,7 @@ class MultiFactorResolverPlatform {
   /// Completes sign in with a second factor using an MultiFactorAssertion which
   /// confirms that the user has successfully completed the second factor challenge.
   Future<UserCredentialPlatform> resolveSignIn(
-    MultiFactorAssertion assertion,
+    MultiFactorAssertionPlatform assertion,
   ) {
     throw UnimplementedError('resolveSignIn() is not implemented');
   }
@@ -139,3 +129,35 @@ class PhoneMultiFactorInfo extends MultiFactorInfo {
   /// The phone number associated with this second factor verification method.
   final String phoneNumber;
 }
+
+/// Helper class used to generate PhoneMultiFactorAssertions.
+class PhoneMultiFactorGeneratorPlatform extends PlatformInterface {
+  static PhoneMultiFactorGeneratorPlatform? _instance;
+
+  static final Object _token = Object();
+
+  PhoneMultiFactorGeneratorPlatform() : super(token: _token);
+
+  /// The current default [PhoneMultiFactorGeneratorPlatform] instance.
+  ///
+  /// It will always default to [MethodChannelPhoneMultiFactorGenerator]
+  /// if no other implementation was provided.
+  static PhoneMultiFactorGeneratorPlatform get instance {
+    _instance ??= MethodChannelPhoneMultiFactorGenerator();
+    return _instance!;
+  }
+
+  /// Sets the [PhoneMultiFactorGeneratorPlatform.instance]
+  static set instance(PhoneMultiFactorGeneratorPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  /// Transforms a PhoneAuthCredential into a [MultiFactorAssertion]
+  /// which can be used to confirm ownership of a phone second factor.
+  MultiFactorAssertionPlatform getAssertion(
+    PhoneAuthCredential credential,
+  ) {
+    throw UnimplementedError('getAssertion() is not implemented');
+  }
+}

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

@@ -80,6 +80,7 @@ abstract class RecaptchaVerifierFactoryPlatform extends PlatformInterface {
   /// Underlying implementations can use this method to create the underlying
   /// implementation of a Recaptcha Verifier.
   RecaptchaVerifierFactoryPlatform delegateFor({
+    required FirebaseAuthPlatform auth,
     String? container,
     RecaptchaVerifierSize size = RecaptchaVerifierSize.normal,
     RecaptchaVerifierTheme theme = RecaptchaVerifierTheme.light,

packages/firebase_auth/firebase_auth_platform_interface/test/platform_interface_tests/platform_interface_recaptcha_verifier_factory_test.dart

@@ -68,7 +68,9 @@ void main() {
     group('delegateFor()', () {
       test('throws UnimplementedError error', () async {
         try {
-          recaptchaVerifierFactoryPlatform.delegateFor();
+          recaptchaVerifierFactoryPlatform.delegateFor(
+            auth: FirebaseAuthPlatform.instance,
+          );
         } on UnimplementedError catch (e) {
           expect(e.message, equals('delegateFor() is not implemented'));
           return;