Saving credentials doesn't work in Safari

[Bartozo]

Description

I have noticed that this plugin does not work correctly on the Safari browser. During the login flow the code stops at the saveCredentials function, which never resolves and does not throw any error, causing the awaited call to hang and leaving users stuck on the login page. However after refreshing the page the user is logged in successfully, which suggests that the token is fetched and stored but the login flow is blocked by this function. Is this a known Safari limitation, is there a recommended workaround or fix, or is it possible to disable this plugin conditionally for Safari only?

Code:

class SaveCredentialsUseCase {
  const SaveCredentialsUseCase({
    this.credentialsSaver = AutologinPlugin.saveCredentials,
  });

  final Future<bool> Function(Credential) credentialsSaver;

  Future<Result> execute({
    required String email,
    required String password,
  }) async {
    try {
      final isSuccess = await credentialsSaver(
        Credential(
          username: email,
          password: password,
          domain: '...',
        ),
      );
      if (!isSuccess) return Failure(Exception("Couldn't save credentials"));

      return const Success(unit);
    } on Exception catch (e) {
      return Failure(Exception("Couldn't save credentials - $e"));
    }
  }
}

Steps to Reproduce

1. Launch the Flutter app on the Web and make sure to choose Safari browser.
2. Try to call the AutologinPlugin.saveCredentials function and make sure to await it.
3. The code is stuck on this function.

Affected Platform

Web,Safari

Flutter Version

Flutter 3.38.5

Plugin Version

autologin: ^1.0.1

Flutter Doctor Output

[✓] Flutter (Channel stable, 3.38.5, on macOS 26.1 25B78 darwin-arm64, locale en-US) [790ms]
    • Flutter version 3.38.5 on channel stable at /Users/bartozo/fvm/versions/3.38.5
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision f6ff1529fd (4 weeks ago), 2025-12-11 11:50:07 -0500
    • Engine revision 1527ae0ec5
    • Dart version 3.10.4
    • DevTools version 2.51.1
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android, enable-ios, cli-animations, enable-native-assets,
      omit-legacy-version-file, enable-lldb-debugging

[✓] Android toolchain - develop for Android devices (Android SDK version 36.1.0) [2.5s]
    • Android SDK at /Users/bartozo/Library/Android/sdk
    • Emulator version 36.1.9.0 (build_id 13823996) (CL:N/A)
    • Platform android-36, build-tools 36.1.0
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.7+-13880790-b1038.58)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 26.2) [2.7s]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 17C52
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [5ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Connected device (4 available) [9.1s]
    • iPhone (Bartozo) (mobile) • 00008130-0018392C02E8001C            • ios            • iOS 26.1 23B85
    • iPhone 16e (mobile)       • 9BE2F574-1666-42E8-975F-E13C22C6A7FA • ios            • com.apple.CoreSimulator.SimRuntime.iOS-26-0 (simulator)
    • macOS (desktop)           • macos                                • darwin-arm64   • macOS 26.1 25B78 darwin-arm64
    • Chrome (web)              • chrome                               • web-javascript • Google Chrome 143.0.7499.170

[✓] Network resources [1,166ms]
    • All expected network resources are available.

• No issues found!

[rekire]

Sorry for my delayed response, I'm a bit busy. I'm planning an update soon where I will check if I can resolve this issue. However the tag "bug" is IMHO wrong since on the demo page is the clear statement that the browser is not supported. However on the first view this can be a false positive. My readme file also mentions that the web support is "[j]ust on chromium based browsers". I'm looking into this feature request.

[rekire]

Based on an old StackOverflow question, MDN and caniuse.com I got the strong feeling that this is simply not supported. If you are a web developer please provide an example code which I can adapt, or feel free to create a PR. Right now I don't see anything I can do to resolve this issue. Thank you for your patience.

[Bartozo]

I understand that the documentation already mentions Safari is not supported. My thought was more about developer experience 🙂 Wouldn’t it be easier if the package itself detected Safari and automatically skipped the logic part, throwing a clear “unsupported browser” error instead? That way it avoids the false positive impression that something is broken. I can also handle this on my side by detecting Safari and skipping the code entirely, but having this check built into the package would be really helpful and make integration safer for others as well.

[rekire]

That's a good feedback, yeah I should throw an exception. My original idea was that the developers use the AutologinPlugin.isPlatformSupported property, but an exception might be easier to understand (and it could point to that property too).

Right now I'm checking if I can add wasm support. Looks more complected then expected.