fix(auth, iOS): include missing email and credential in account-exists-with-different-credential error (#17180)

* fix(auth, iOS): include missing email and credential in account-exists-with-different-credential error

* chore: use `convertToFlutterError` function

* chore: revert indentation

* chore: revert indentation

* chore: fix formatting issues

Author: SelaseKay

packages/firebase_auth/firebase_auth/ios/firebase_auth/Sources/firebase_auth/FLTFirebaseAuthPlugin.m

@@ -602,51 +602,58 @@ static void handleAppleAuthResult(FLTFirebaseAuthPlugin *object, AuthPigeonFireb
     return;
   }
   if (credentials) {
-    [auth signInWithCredential:credentials
-                    completion:^(FIRAuthDataResult *authResult, NSError *error) {
-                      if (error != nil) {
-                        NSDictionary *userInfo = [error userInfo];
-                        NSError *underlyingError = [userInfo objectForKey:NSUnderlyingErrorKey];
-
-                        NSDictionary *firebaseDictionary =
-                            underlyingError.userInfo[@"FIRAuthErrorUserInfoDes"
-                                                     @"erializedResponseKey"];
-
-                        if (firebaseDictionary == nil &&
-                            userInfo[@"FIRAuthErrorUserInfoNameKey"] != nil) {
-                          // Removing since it's not parsed and causing issue when sending back the
-                          // object to Flutter
-                          NSMutableDictionary *mutableUserInfo = [userInfo mutableCopy];
-                          [mutableUserInfo
-                              removeObjectForKey:@"FIRAuthErrorUserInfoUpdatedCredentialKey"];
-                          NSError *modifiedError = [NSError errorWithDomain:error.domain
-                                                                       code:error.code
-                                                                   userInfo:mutableUserInfo];
-
-                          completion(nil,
-                                     [FlutterError errorWithCode:@"sign-in-failed"
-                                                         message:userInfo[@"NSLocalizedDescription"]
-                                                         details:modifiedError.userInfo]);
-
-                        } else if (firebaseDictionary != nil &&
-                                   firebaseDictionary[@"message"] != nil) {
-                          // error from firebase-ios-sdk is
-                          // buried in underlying error.
-                          completion(nil,
-                                     [FlutterError errorWithCode:@"sign-in-failed"
-                                                         message:error.localizedDescription
-                                                         details:firebaseDictionary[@"message"]]);
-                        } else {
-                          completion(nil, [FlutterError errorWithCode:@"sign-in-failed"
-                                                              message:error.localizedDescription
-                                                              details:error.userInfo]);
+    [auth
+        signInWithCredential:credentials
+                  completion:^(FIRAuthDataResult *authResult, NSError *error) {
+                    if (error != nil) {
+                      NSDictionary *userInfo = [error userInfo];
+                      NSError *underlyingError = [userInfo objectForKey:NSUnderlyingErrorKey];
+
+                      NSDictionary *firebaseDictionary =
+                          underlyingError.userInfo[@"FIRAuthErrorUserInfoDes"
+                                                   @"erializedResponseKey"];
+
+                      NSString *errorCode = userInfo[@"FIRAuthErrorUserInfoNameKey"];
+
+                      if (firebaseDictionary == nil && errorCode != nil) {
+                        if ([errorCode isEqual:@"ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL"]) {
+                          completion(nil, [FLTFirebaseAuthPlugin convertToFlutterError:error]);
+                          return;
                         }
+
+                        // Removing since it's not parsed and causing issue when sending back the
+                        // object to Flutter
+                        NSMutableDictionary *mutableUserInfo = [userInfo mutableCopy];
+                        [mutableUserInfo
+                            removeObjectForKey:@"FIRAuthErrorUserInfoUpdatedCredentialKey"];
+                        NSError *modifiedError = [NSError errorWithDomain:error.domain
+                                                                     code:error.code
+                                                                 userInfo:mutableUserInfo];
+
+                        completion(nil,
+                                   [FlutterError errorWithCode:@"sign-in-failed"
+                                                       message:userInfo[@"NSLocalizedDescription"]
+                                                       details:modifiedError.userInfo]);
+
+                      } else if (firebaseDictionary != nil &&
+                                 firebaseDictionary[@"message"] != nil) {
+                        // error from firebase-ios-sdk is
+                        // buried in underlying error.
+                        completion(nil,
+                                   [FlutterError errorWithCode:@"sign-in-failed"
+                                                       message:error.localizedDescription
+                                                       details:firebaseDictionary[@"message"]]);
                       } else {
-                        completion([PigeonParser getPigeonUserCredentialFromAuthResult:authResult
-                                                                     authorizationCode:nil],
-                                   nil);
+                        completion(nil, [FlutterError errorWithCode:@"sign-in-failed"
+                                                            message:error.localizedDescription
+                                                            details:error.userInfo]);
                       }
-                    }];
+                    } else {
+                      completion([PigeonParser getPigeonUserCredentialFromAuthResult:authResult
+                                                                   authorizationCode:nil],
+                                 nil);
+                    }
+                  }];
   }
 }