CancelToken problem in Flutter version 3.13.2

[menghui0330]

Package

dio

Version

5.3.2

Output of flutter doctor -v

[✓] Flutter (Channel stable, 3.13.2, on macOS 13.5.1 22G90 darwin-arm64, locale en-MY)
    • Flutter version 3.13.2 on channel stable at /Users/menghui/fvm/versions/stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ff5b5b5fa6 (2 weeks ago), 2023-08-24 08:12:28 -0500
    • Engine revision b20183e040
    • Dart version 3.1.0
    • DevTools version 2.25.0

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0)
    • Android SDK at /Users/menghui/Library/Android/sdk
    • Platform android-33, build-tools 33.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.13+0-b1751.21-8125866)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 14.3.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14E300c
    • CocoaPods version 1.12.1

[✓] Android Studio (version 2021.3)
    • 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 11.0.13+0-b1751.21-8125866)

[✓] VS Code (version 1.81.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.72.0

[✓] Connected device (1 available)
    • iPhone SE (3rd generation) (mobile) • F1DC1D3B-48E9-4803-A860-A2CD6F1054FE • ios • com.apple.CoreSimulator.SimRuntime.iOS-16-4 (simulator)

[✓] Network resources
    • All expected network resources are available.

• No issues found!

Dart Version

3.1.0

Steps to Reproduce

1. Call an API with cancelation token provided
2. Wait for response
3. Trigger cancel token

Expected Result

Nothing happen

Actual Result

Exception

[menghui0330]

Never had this problem with flutter 3.10, but keep getting uncaught exception in 3.13

[kuhnroyal]

Please see the comment and answers: #1869 (comment)
In short, this is likely a change in Flutter and/or its interaction with VSCode, nothing we can do anything about.

[lonelyteapot]

This may have been fixed in Flutter master. Reference: dart-lang/sdk#47985

[kuhnroyal]

Yea I think we can close this issue, please follow the Dart SDK issue for updates to Dart/Flutter.
There is nothing dio can do about it.

[YDA93]

still exists in Flutter Channel stable, 3.13.9. the bug is annoying

[kuhnroyal]

Please follow the mentioned Dart SDK issue, nothing we can do here.

[tomekit]

In short, this is likely a change in Flutter and/or its interaction with VSCode, nothing we can do anything about.

We experience the same in the Android Studio IDE and we suspect this is what breaks the cancel token for stream response as described here: #2025

Present in the function: dio-5.3.3/lib/src/dio_mixin.dart:

 @internal
  static Future<T> listenCancelForAsyncTask<T>(
    CancelToken? cancelToken,
    Future<T> future,
  ) {
    return Future.any([
      if (cancelToken != null) cancelToken.whenCancel.then((e) {
        throw e;
      }),
      future,
    ]);
  }

[tomekit]

I think this issue shall be reopened.

The related Dart issue that was mentioned in this ticket: dart-lang/sdk#47985 or #1869 (comment) applies to debugger problems, however cancellation doesn't seem to work fine regardless of IDE / debugger used. It doesn't even work in the release version of the app.

In other words cancellation doesn't work for Dio as reported in this issue: #2025 even if app is built using release mode.

This issue was closed as "Out of support" without valid references to external issues.
It would be good to narrow down the problem to either Dio itself or Dart SDK... and if the issue lies within Dart SDK it would be great to link to any existing issue or create a new one: https://github.com/dart-lang/sdk/issues