无法捕获Firebase Auth的'email-already-in-use'错误求助

在使用Firebase Auth实现邮箱注册逻辑时，重复使用同一邮箱注册，预设的Snackbar并未弹出，无法正确捕获'email-already-in-use'错误。

注册逻辑代码 #

class FirebaseAuthFailure implements IauthFailure {
  final FirebaseAuth firebaseAuth;
  final GoogleSignIn googleSignIn;

  FirebaseAuthFailure(this.firebaseAuth, this.googleSignIn);
  @override
  Future<Either<AuthFailure, Unit>> registerWithEmailAndPassword(
      {required EmailAddress emailAddress, required Password password}) async {
    final emailAddressStr = emailAddress.value
        .fold((left) => throw UnexpectedValueError(left), (right) => right);
    final passwordStr = password.value
        .fold((left) => throw UnexpectedValueError(left), (right) => right);
    try {
      await firebaseAuth.createUserWithEmailAndPassword(
          email: emailAddressStr, password: passwordStr);
      return right(unit);
    } on PlatformException catch (e) {
      if (e.code == 'email-already-in-use') {
        return left(const AuthFailure.emailalreadyinuse());
      } else {
        return left(const AuthFailure.servererror());
      }
    }
  }
}

Snackbar相关代码 #

BlocConsumer<AuthBloc, AuthState>(
              listener: (context, state) {
                state.authfailureorsuccess.fold(
                    () {},
                    (either) => either.fold((failure) {
                          FlushbarHelper.createError(
                            message: failure.map(
                                cancelledbyuser: (_) => 'Cancelled',
                                servererror: (_) => 'Server Error',
                                emailalreadyinuse: (_) =>
                                    'Email Already In Use',
                                invalidemailandpasswordcomnination: (_) =>
                                    'Invalid Email And Password Combination'),
                          ).show(context);
                        }, (_) {}));
              },
)

控制台错误信息 #

I/FirebaseAuth(29404): Creating user with nidhinvninan29@gmail.com with empty reCAPTCHA token
W/System (29404): Ignoring header X-Firebase-Locale because its value was null.
E/RecaptchaCallWrapper(29404): Initial task failed for action RecaptchaAction(action=signUpPassword)with exception - The email address is already in use by another account.
E/flutter (29404): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: Unhandled error [firebase_auth/email-already-in-use] The email address is already in use by another account. occurred in Instance of 'AuthBloc'.

已尝试的无效方案 #

• 匹配e.code == 'email-already-in-use:'
• 匹配e.code == 'firebase_auth/email-already-in-use'

解决方案 #

问题核心在于异常捕获的类型错误：Firebase Auth当前抛出的是FirebaseAuthException而非PlatformException，原代码的on PlatformException catch (e)无法捕获到目标错误。

修改注册逻辑的异常捕获部分：

try {
  await firebaseAuth.createUserWithEmailAndPassword(
      email: emailAddressStr, password: passwordStr);
  return right(unit);
} on FirebaseAuthException catch (e) { // 替换为FirebaseAuthException类型捕获
  if (e.code == 'email-already-in-use') {
    return left(const AuthFailure.emailalreadyinuse());
  } else {
    return left(const AuthFailure.servererror());
  }
} catch (e) { // 兜底捕获其他未知异常
  return left(const AuthFailure.servererror());
}

同时确保已导入Firebase Auth相关包：

import 'package:firebase_auth/firebase_auth.dart';

修改后即可正确捕获email-already-in-use错误，触发对应的Snackbar提示。

内容的提问来源于stack exchange，提问作者nidhin ninan