[Firebase Auth] didn't get email, credential in case of email-already-in-use error code

[mabujaber]

Bug report

Describe the bug
in case of user already exist with a different provider will get the error code email-already-in-use and in the FirebaseAuthException has these values email, credential ...etc but when I tried to access them but unfortunately all the values are null.

Why need these value, I want to link the email trying to login with one of the third-party sign-in such as Facebook, apple ...etc instead of having one account for multiple providers.

For instance, we have two methods of sign-in (Facebook and Apple) when I sign-in using Facebook and try to use the same email account in apple sign-in will get the above error email-already-in-use but unable to link them due to unavalibility for the above fields

Steps to reproduce

1- Sign in with facebook
2- signout
3- sign in with apple that has the same email address you signed in step 1
4- you will get the error email-already-in-use without providing email, credential ...etc

Expected behavior

I should get the same error with providing me the fields (email, credential ...etc)

[markusaksli-nc]

Hi @mabujaber
Could you please provide your flutter doctor -v and flutter pub deps -- --style=compact?
Thank you

[mabujaber]

flutter doctor -v

[✓] Flutter (Channel stable, 2.0.2, on Mac OS X 10.15.7 19H2 darwin-x64,
    locale en-JO)
    • Flutter version 2.0.2 at /Users/mabujaber/tools/flutter
    • Framework revision 8962f6dc68 (3 weeks ago), 2021-03-11 13:22:20 -0800
    • Engine revision 5d8bf811b3
    • Dart version 2.12.1

[✓] Android toolchain - develop for Android devices (Android SDK version
    29.0.3)
    • Android SDK at /Users/mabujaber/Library/Android/sdk
    • Platform android-30, build-tools 29.0.3
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.0

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6915495)

[✓] IntelliJ IDEA Ultimate Edition (version 2020.3.2)
    • IntelliJ at /Applications/IntelliJ IDEA.app
    • Flutter plugin version 54.0.3
    • Dart plugin version 203.7759

[✓] VS Code (version 1.54.3)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.20.0

[✓] Connected device (1 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 89.0.4389.90

• No issues found!

flutter pub deps -- --style=compact

Dart SDK 2.12.1
Flutter SDK 2.0.2
trynkets_app 1.0.0+7

dependencies:
- badges 1.2.0 [flutter]
- carousel_slider 3.0.0 [flutter]
- cloud_firestore 1.0.0 [cloud_firestore_platform_interface cloud_firestore_web firebase_core firebase_core_platform_interface flutter meta]
- confetti 0.5.5 [flutter random_color vector_math]
- crypto 2.1.5 [collection convert typed_data]
- cupertino_icons 1.0.2
- firebase_analytics 7.1.1 [firebase_analytics_platform_interface firebase_analytics_web firebase_core flutter meta]
- firebase_auth 1.0.1 [firebase_auth_platform_interface firebase_auth_web firebase_core firebase_core_platform_interface flutter meta]
- firebase_core 1.0.0 [firebase_core_platform_interface firebase_core_web flutter meta]
- firebase_crashlytics 1.0.0 [firebase_core firebase_core_platform_interface firebase_crashlytics_platform_interface flutter stack_trace]
- firebase_database 6.1.0 [flutter firebase_core]
- firebase_messaging 9.0.0 [firebase_core firebase_core_platform_interface firebase_messaging_platform_interface firebase_messaging_web flutter meta]
- firebase_performance 0.6.0 [flutter firebase_core]
- firebase_storage 8.0.0 [firebase_core firebase_core_platform_interface firebase_storage_platform_interface firebase_storage_web flutter]
- flutter 0.0.0 [characters collection meta typed_data vector_math sky_engine]
- flutter_app_badger 1.1.2 [flutter]
- flutter_localizations 0.0.0 [flutter intl characters clock collection meta path typed_data vector_math]
- flutter_login_facebook 0.5.0 [flutter list_ext]
- flutter_sequence_animation 3.0.1 [flutter meta]
- freezed_annotation 0.12.0 [collection json_annotation meta]
- geocoder 0.2.1 [meta flutter]
- geolocator 7.0.1 [flutter geolocator_platform_interface geolocator_web]
- google_maps_flutter 2.0.1 [flutter flutter_plugin_android_lifecycle google_maps_flutter_platform_interface]
- http 0.13.0 [http_parser meta path pedantic]
- intl 0.17.0 [clock path]
- json_annotation 3.1.1
- logging 1.0.0
- page_transition 1.1.7+6 [flutter]
- shared_preferences 2.0.3 [meta flutter shared_preferences_platform_interface shared_preferences_linux shared_preferences_macos shared_preferences_web shared_preferences_windows]
- showcaseview 0.1.6 [flutter]
- sign_in_with_apple 2.5.4 [meta flutter]
- states_rebuilder 3.2.0 [flutter collection]
- typicons_flutter 0.4.2 [flutter]
- url_launcher 6.0.2 [flutter url_launcher_platform_interface url_launcher_linux url_launcher_macos url_launcher_windows url_launcher_web]
- url_launcher_platform_interface 2.0.2 [flutter plugin_platform_interface]
- wakelock 0.2.1+1 [flutter meta wakelock_platform_interface wakelock_web]

dev dependencies:
- build_runner 1.11.5 [args async build build_config build_daemon build_resolvers build_runner_core code_builder collection crypto dart_style glob graphs http_multi_server io js logging meta mime path pedantic pool pub_semver pubspec_parse shelf shelf_web_socket stack_trace stream_transform timing watcher web_socket_channel yaml]
- flutter_test 0.0.0 [flutter test_api path fake_async clock stack_trace vector_math async boolean_selector characters charcode collection matcher meta source_span stream_channel string_scanner term_glyph typed_data]
- freezed 0.12.7 [analyzer build build_config meta source_gen freezed_annotation]
- json_serializable 3.5.1 [analyzer build build_config json_annotation meta path source_gen]
- lint 1.5.2

transitive dependencies:
- _fe_analyzer_shared 14.0.0 [meta]
- analyzer 0.41.2 [_fe_analyzer_shared args cli_util collection convert crypto glob meta package_config path pub_semver source_span watcher yaml]
- args 1.6.0
- async 2.5.0 [collection]
- boolean_selector 2.1.0 [source_span string_scanner]
- build 1.6.2 [analyzer async convert crypto glob logging meta path]
- build_config 0.4.6 [checked_yaml json_annotation meta path pubspec_parse yaml]
- build_daemon 2.1.8 [built_collection built_value http_multi_server logging pedantic path pool shelf shelf_web_socket stream_transform watcher web_socket_channel]
- build_resolvers 1.5.3 [analyzer build crypto graphs logging meta path package_config pool pub_semver]
- build_runner_core 6.1.10 [async build build_config build_resolvers collection convert crypto glob graphs logging meta path package_config pedantic pool timing watcher yaml]
- built_collection 5.0.0
- built_value 8.0.0 [built_collection collection fixnum]
- characters 1.1.0
- charcode 1.2.0
- checked_yaml 1.0.4 [json_annotation source_span yaml]
- cli_util 0.2.0 [path]
- clock 1.1.0
- cloud_firestore_platform_interface 4.0.0 [collection firebase_core flutter meta plugin_platform_interface]
- cloud_firestore_web 1.0.0 [cloud_firestore_platform_interface firebase_core firebase_core_web flutter flutter_web_plugins js]
- code_builder 3.6.0 [built_collection built_value collection matcher meta]
- collection 1.15.0
- convert 2.1.1 [charcode typed_data]
- csslib 0.16.2 [source_span]
- dart_style 1.3.12 [analyzer args path pub_semver source_span]
- fake_async 1.2.0 [clock collection]
- ffi 1.0.0
- file 6.1.0 [meta path]
- firebase 9.0.0 [http http_parser js]
- firebase_analytics_platform_interface 1.1.0 [flutter meta]
- firebase_analytics_web 0.2.0+1 [firebase firebase_analytics_platform_interface flutter flutter_web_plugins meta]
- firebase_auth_platform_interface 4.0.0 [firebase_core flutter meta plugin_platform_interface]
- firebase_auth_web 1.0.1 [firebase_auth_platform_interface firebase_core firebase_core_web flutter flutter_web_plugins http_parser intl js meta]
- firebase_core_platform_interface 4.0.0 [flutter meta plugin_platform_interface]
- firebase_core_web 1.0.0 [firebase_core_platform_interface flutter flutter_web_plugins js meta]
- firebase_crashlytics_platform_interface 2.0.0 [collection firebase_core flutter meta plugin_platform_interface]
- firebase_messaging_platform_interface 2.0.0 [firebase_core flutter meta plugin_platform_interface]
- firebase_messaging_web 1.0.0 [firebase_core firebase_core_web firebase_messaging_platform_interface flutter flutter_web_plugins js meta]
- firebase_storage_platform_interface 2.0.0 [collection firebase_core flutter meta plugin_platform_interface]
- firebase_storage_web 1.0.0 [async firebase_core firebase_core_web firebase_storage_platform_interface flutter flutter_web_plugins http js meta]
- fixnum 1.0.0
- flutter_plugin_android_lifecycle 2.0.0 [flutter]
- flutter_web_plugins 0.0.0 [flutter js characters collection meta typed_data vector_math]
- geolocator_platform_interface 2.0.0 [flutter plugin_platform_interface vector_math meta]
- geolocator_web 2.0.1 [flutter flutter_web_plugins geolocator_platform_interface]
- glob 2.0.0 [async collection file path pedantic string_scanner]
- google_maps_flutter_platform_interface 2.0.1 [flutter meta plugin_platform_interface stream_transform collection]
- graphs 0.2.0
- html 0.14.0+4 [csslib source_span]
- http_multi_server 2.2.0 [async]
- http_parser 4.0.0 [charcode collection source_span string_scanner typed_data]
- import_js_library 1.0.2 [flutter html flutter_web_plugins js]
- io 0.3.4 [charcode meta path string_scanner]
- js 0.6.3
- list_ext 0.2.0 [quiver collection]
- matcher 0.12.10 [stack_trace]
- meta 1.3.0
- mime 0.9.7
- package_config 1.9.3 [path charcode]
- path 1.8.0
- path_provider_linux 2.0.0 [path xdg_directories path_provider_platform_interface flutter]
- path_provider_platform_interface 2.0.1 [flutter meta platform plugin_platform_interface]
- path_provider_windows 2.0.0 [path_provider_platform_interface meta path flutter ffi win32]
- pedantic 1.11.0
- platform 3.0.0
- plugin_platform_interface 2.0.0 [meta]
- pool 1.4.0 [async stack_trace]
- process 4.1.0 [file path platform]
- pub_semver 1.4.4 [collection]
- pubspec_parse 0.1.8 [checked_yaml json_annotation pub_semver yaml]
- quiver 2.1.5 [matcher meta]
- random_color 1.0.6-nullsafety [flutter]
- shared_preferences_linux 2.0.0 [flutter file meta path path_provider_linux shared_preferences_platform_interface]
- shared_preferences_macos 2.0.0 [shared_preferences_platform_interface flutter]
- shared_preferences_platform_interface 2.0.0 [flutter]
- shared_preferences_web 2.0.0 [shared_preferences_platform_interface flutter flutter_web_plugins meta]
- shared_preferences_windows 2.0.0 [shared_preferences_platform_interface flutter file meta path path_provider_platform_interface path_provider_windows]
- shelf 1.0.0 [async collection http_parser path stack_trace stream_channel]
- shelf_web_socket 0.2.4+1 [shelf stream_channel web_socket_channel]
- sky_engine 0.0.99
- source_gen 0.9.10+3 [analyzer async build dart_style glob meta path pedantic source_span]
- source_span 1.8.0 [charcode collection path term_glyph]
- stack_trace 1.10.0 [path]
- stream_channel 2.1.0 [async]
- stream_transform 2.0.0
- string_scanner 1.1.0 [charcode source_span]
- term_glyph 1.2.0
- test_api 0.2.19 [async boolean_selector collection meta path source_span stack_trace stream_channel string_scanner term_glyph matcher]
- timing 0.1.1+3 [json_annotation]
- typed_data 1.3.0 [collection]
- url_launcher_linux 2.0.0 [flutter]
- url_launcher_macos 2.0.0 [flutter]
- url_launcher_web 2.0.0 [url_launcher_platform_interface meta flutter flutter_web_plugins]
- url_launcher_windows 2.0.0 [flutter]
- vector_math 2.1.0
- wakelock_platform_interface 0.1.0+1 [flutter meta]
- wakelock_web 0.1.0+3 [flutter flutter_web_plugins import_js_library js wakelock_platform_interface]
- watcher 0.9.7+15 [async path pedantic]
- web_socket_channel 1.1.0 [async crypto stream_channel]
- win32 2.0.0 [ffi]
- xdg_directories 0.2.0 [meta path process]
- yaml 2.2.1 [charcode collection string_scanner source_span]

[mabujaber]

and here the login logic and will add a comment where should I receive the stored firebase data

Future<User> loginApple() async {
    appleError.state = false;
    facebookError.state = false;

    // //check if the device supports apple sign in
    if (!await SignInWithApple.isAvailable()) {
      return null;
    }

    final rawNonce = generateNonce();
    final nonce = sha256ofString(rawNonce);

    final appleCredential = await SignInWithApple.getAppleIDCredential(
      scopes: [
        AppleIDAuthorizationScopes.email,
        AppleIDAuthorizationScopes.fullName,
      ],
      nonce: nonce,
    ).catchError((_) {
      return null;
    });

    if (appleCredential == null) return null;

    final oauthCredential = OAuthProvider("apple.com").credential(
      idToken: appleCredential.identityToken,
      rawNonce: rawNonce,
    );

    if (oauthCredential == null) return null;

    //user data
    final userInAppleResult = {
      'email': appleCredential.email,
      'givenName': appleCredential.givenName,
      'familyName': appleCredential.familyName,
      'name': '${appleCredential.givenName} ${appleCredential.familyName}'
    };

    logger.fine(userInAppleResult);
    logger.fine(oauthCredential);

    try {
      //new users

      await _auth.currentUser
          .linkWithCredential(oauthCredential)
          .then((usercred) async {
        logger.fine('the user came from apple $usercred');

        final res = usercred.additionalUserInfo.profile;
        logger.fine(res);

        userInAppleResult['email'] = userInAppleResult['email'] ??
            usercred.additionalUserInfo.profile['email'] as String;

        logger.fine(AppleUser.fromJson(userInAppleResult));

        user = await userService.saveFromApple(
            AppleUser.fromJson(userInAppleResult), usercred.user.uid);
      });
    } on FirebaseAuthException catch (authException) {
      logger.fine(' all fields $authException');
      logger.fine('error in linking ${authException.credential}');
      await _auth.signOut();

      if (authException.code == 'email-already-in-use') {
       /// when I do check the fields of authException.credential and authException.email will be empty 
        await anonymousLogin();

        appleError.state = true;

        return null;
      }

      try {
        //here in case of the user exist with same provider but different credential 
        final res = await _auth.signInWithCredential(authException.credential);

        userInAppleResult['email'] = userInAppleResult['email'] ??
            res.additionalUserInfo.profile['email'] as String;

        logger.fine(AppleUser.fromJson(userInAppleResult));

        user = await userService.saveFromApple(
            AppleUser.fromJson(userInAppleResult), res.user.uid,
            newUser: false);
      } on FirebaseAuthException catch (signingException) {
       // I made this because I faced issue that the user exist and with same provider and has different credential 
       // but unable to login when I get the credential from the the authException neither from the created new credential 
        logger.severe('There is Error in Logging exist user $signingException');

        user = null;
        await _auth.signOut();
        anonymousLogin();
      }
    }

    return user;
  }```

[markusaksli-nc]

The problem with facebook login on the native side is that it does not provide an account with a verified email so you need to verify it yourself. Does the issue persist if the account is verified?

[mabujaber]

The problem with facebook login on the native side is that it does not provide an account with a verified email so you need to verify it yourself. Does the issue persist if the account is verified?

I'm not sure what you mean but all the account we test them are verified but the issue ain't only with facebook. the issue happened even if I tried to log in with apple and the account exist will return nulls vice versa