Flutterfire: 🐛 [firebase_auth] email always returns null when user has no provider

[stx]

Bug report

A user's email address will always return null, even when it is set in Firebase, if the user lacks a provider. Works as expected in the Admin SDK and Firebase web client SDK.

Steps to reproduce

1. Create a user and auth token in the backend:

user = admin.auth().createUser({
  email: email,
  emailVerified: true,
});

token = admin.auth().createCustomToken(user.uid);

Note that this creates a user, with this email, but without any provider.

1. Fire signInWithCustomToken in Flutter using token.

email is null for the returned user data and the future returned user data. A signed-in user is propagated with a null email through the FirebaseAuth stream. The email will remain null even when set using updateEmail.

Workaround

Create the user with a password, and it will be classified with an Email Provider, and the email will be returned.

Expected behavior

The email is always returned if it is set in Firebase.

---

Flutter doctor

Run flutter doctor and paste the output below:

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Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, 1.24.0-10.2.pre, on Mac OS X 10.15.7 19H2 darwin-x64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[✓] Xcode - develop for iOS and macOS (Xcode 12.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.0)
[✓] VS Code (version 1.51.1)
[✓] Connected device (3 available)

• No issues found!

---

Flutter dependencies

Run flutter pub deps -- --style=compact and paste the output below:

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Dart SDK 2.12.0-29.10.beta
Flutter SDK 1.24.0-10.2.pre

dependencies:
- chewie 0.12.0 [video_player cupertino_icons wakelock flutter]
- cloud_firestore 0.14.3 [flutter meta quiver firebase_core firebase_core_platform_interface cloud_firestore_platform_interface cloud_firestore_web]
- cloud_functions 0.6.0+1 [meta flutter firebase_core cloud_functions_platform_interface cloud_functions_web]
- email_validator 1.0.6
- expandable 4.1.4 [flutter]
- firebase_auth 0.18.3 [meta firebase_core firebase_core_platform_interface firebase_auth_platform_interface firebase_auth_web flutter]
- firebase_core 0.5.2 [firebase_core_platform_interface flutter quiver meta firebase_core_web]
- firebase_crashlytics 0.2.3 [flutter stack_trace firebase_core firebase_core_platform_interface firebase_crashlytics_platform_interface]
- firebase_dynamic_links 0.6.2 [flutter firebase_core]
- firebase_messaging 7.0.3 [meta flutter firebase_core]
- firebase_performance 0.4.2 [flutter firebase_core]
- flutter 0.0.0 [characters collection meta typed_data vector_math sky_engine]
- flutter_localizations 0.0.0 [flutter intl characters collection meta path typed_data vector_math]
- flutter_secure_storage 3.3.5 [meta flutter]
- flutter_spinkit 4.1.2+1 [flutter]
- font_awesome_flutter 8.10.0 [flutter]
- geocoder 0.2.1 [meta flutter]
- get_it 5.0.1 [async meta]
- google_maps_flutter 1.0.6 [flutter flutter_plugin_android_lifecycle google_maps_flutter_platform_interface]
- google_maps_webservice 0.0.18 [http meta]
- http 0.12.2 [http_parser path pedantic]
- in_app_review 1.0.3 [flutter in_app_review_platform_interface]
- local_auth 0.6.3+4 [flutter meta intl platform flutter_plugin_android_lifecycle]
- location 3.1.0 [flutter meta location_platform_interface location_web]
- logger 0.9.4
- modal_bottom_sheet 1.0.0+1 [flutter]
- package_info 0.4.3+2 [flutter]
- path 1.8.0-nullsafety.3
- pinput 0.2.6 [flutter]
- progress_dialog 1.2.4 [flutter]
- purchases_flutter 1.4.3 [flutter]
- recase 3.0.1
- rxdart 0.24.1
- shared_preferences 0.5.12+4 [meta flutter shared_preferences_platform_interface shared_preferences_linux shared_preferences_macos shared_preferences_web shared_preferences_windows]
- sqflite 1.3.1+2 [flutter sqflite_common path]
- syncfusion_flutter_charts 18.2.59 [flutter intl vector_math syncfusion_flutter_core]
- timeago 2.0.28
- universal_platform 0.1.3
- url_launcher 5.7.10 [flutter url_launcher_platform_interface url_launcher_web url_launcher_linux url_launcher_macos url_launcher_windows]
- vibrate 0.0.4 [flutter]
- video_player 1.0.1 [meta video_player_platform_interface video_player_web flutter]

dev dependencies:
- flutter_launcher_icons 0.8.1 [image args yaml path]
- 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]

transitive dependencies:
- archive 2.0.13 [crypto args path]
- args 1.6.0
- async 2.5.0-nullsafety.3 [collection]
- boolean_selector 2.1.0-nullsafety.3 [source_span string_scanner]
- characters 1.1.0-nullsafety.5
- charcode 1.2.0-nullsafety.3
- clock 1.1.0-nullsafety.3
- cloud_firestore_platform_interface 2.2.0 [flutter meta collection firebase_core plugin_platform_interface]
- cloud_firestore_web 0.2.1 [flutter flutter_web_plugins http_parser meta firebase_core firebase_core_web cloud_firestore_platform_interface js]
- cloud_functions_platform_interface 2.0.0 [flutter meta firebase_core plugin_platform_interface]
- cloud_functions_web 2.0.0 [cloud_functions_platform_interface flutter flutter_web_plugins firebase http_parser meta]
- collection 1.15.0-nullsafety.5
- convert 2.1.1 [charcode typed_data]
- crypto 2.1.5 [collection convert typed_data]
- csslib 0.16.2 [source_span]
- cupertino_icons 1.0.1+1
- fake_async 1.2.0-nullsafety.3 [clock collection]
- ffi 0.1.3
- file 5.2.1 [intl meta path]
- firebase 7.3.2 [http http_parser js]
- firebase_auth_platform_interface 2.1.3 [flutter meta firebase_core plugin_platform_interface]
- firebase_auth_web 0.3.2 [flutter flutter_web_plugins meta http_parser intl firebase_core firebase_core_web firebase_auth_platform_interface js]
- firebase_core_platform_interface 2.0.0 [flutter meta plugin_platform_interface quiver]
- firebase_core_web 0.2.1 [firebase_core_platform_interface flutter flutter_web_plugins meta js]
- firebase_crashlytics_platform_interface 1.1.3 [flutter meta collection firebase_core plugin_platform_interface]
- flutter_plugin_android_lifecycle 1.0.11 [flutter]
- flutter_web_plugins 0.0.0 [flutter js characters collection meta typed_data vector_math]
- google_maps_flutter_platform_interface 1.0.5 [flutter meta plugin_platform_interface stream_transform]
- html 0.14.0+4 [csslib source_span]
- http_parser 3.1.4 [charcode collection source_span string_scanner typed_data]
- image 2.1.19 [archive xml meta]
- import_js_library 1.0.2 [flutter html flutter_web_plugins js]
- in_app_review_platform_interface 1.0.4 [flutter url_launcher package_info plugin_platform_interface]
- intl 0.16.1 [path]
- js 0.6.3-nullsafety.3
- location_platform_interface 1.0.1 [flutter meta plugin_platform_interface]
- location_web 1.0.0 [flutter flutter_web_plugins location_platform_interface http_parser meta js]
- matcher 0.12.10-nullsafety.3 [stack_trace]
- meta 1.3.0-nullsafety.6
- path_provider_linux 0.0.1+2 [path xdg_directories path_provider_platform_interface flutter]
- path_provider_platform_interface 1.0.4 [flutter meta platform plugin_platform_interface]
- path_provider_windows 0.0.4+3 [path_provider_platform_interface meta path flutter ffi win32]
- pedantic 1.9.2 [meta]
- petitparser 3.1.0 [meta]
- platform 2.2.1
- plugin_platform_interface 1.0.3 [meta]
- process 3.0.13 [file intl meta path platform]
- quiver 2.1.5 [matcher meta]
- shared_preferences_linux 0.0.2+4 [file flutter meta path path_provider_linux shared_preferences_platform_interface]
- shared_preferences_macos 0.0.1+11 [shared_preferences_platform_interface flutter]
- shared_preferences_platform_interface 1.0.4 [meta flutter]
- shared_preferences_web 0.1.2+7 [shared_preferences_platform_interface flutter flutter_web_plugins meta]
- shared_preferences_windows 0.0.1+3 [shared_preferences_platform_interface flutter ffi file meta path path_provider_platform_interface path_provider_windows]
- sky_engine 0.0.99
- source_span 1.8.0-nullsafety.4 [charcode collection path term_glyph]
- sqflite_common 1.0.2+1 [synchronized path meta]
- stack_trace 1.10.0-nullsafety.6 [path]
- stream_channel 2.1.0-nullsafety.3 [async]
- stream_transform 1.2.0
- string_scanner 1.1.0-nullsafety.3 [charcode source_span]
- syncfusion_flutter_core 18.3.50 [flutter pedantic]
- synchronized 2.2.0+2
- term_glyph 1.2.0-nullsafety.3
- test_api 0.2.19-nullsafety.6 [async boolean_selector collection meta path source_span stack_trace stream_channel string_scanner term_glyph matcher]
- typed_data 1.3.0-nullsafety.5 [collection]
- url_launcher_linux 0.0.1+4 [flutter]
- url_launcher_macos 0.0.1+9 [flutter]
- url_launcher_platform_interface 1.0.9 [flutter meta plugin_platform_interface]
- url_launcher_web 0.1.5+1 [url_launcher_platform_interface flutter flutter_web_plugins meta]
- url_launcher_windows 0.0.1+3 [flutter]
- vector_math 2.1.0-nullsafety.5
- video_player_platform_interface 2.2.0 [flutter meta]
- video_player_web 0.1.4+1 [flutter flutter_web_plugins meta video_player_platform_interface]
- wakelock 0.2.1+1 [flutter meta wakelock_platform_interface wakelock_web]
- 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]
- win32 1.7.4 [ffi]
- xdg_directories 0.1.2 [meta path process]
- xml 4.5.1 [collection convert meta petitparser]
- yaml 2.2.1 [charcode collection string_scanner source_span]

---

[brosnic]

Thank you @stx for your report! I just wanted to write the same bug report.

Here are my additional findings:

• It works for Android but not for iOS.

• The code where the email is set to null is here: https://github.com/FirebaseExtended/flutterfire/blob/2b038bea37d6f6156fd18a1b9d0d1baa2b3730fe/packages/firebase_auth/firebase_auth/ios/Classes/FLTFirebaseAuthPlugin.m#L1253

[markusaksli-nc]

Admin SDK is technically out of scope here but supporting users with no providers (as well as parity) should be in the scope of auth.