flutter_test framework does not run isolates/handle isolate message sending properly #21093

GaryQian · 2018-08-28T00:59:05Z

Isolates are unable to send and receive messages properly when running flutter_test tests. For example, even very simple ping-pong style messages either fail to send or the isolate may fail to run at all.

import 'dart:isolate';
import 'package:unittest/unittest.dart';

child(args) {
  var msg = args[0];
  var reply = args[1];
  print("msg = $msg, reply = $reply");
  reply.send('re: $msg');
}

void main([args, port]) {
  test('message - reply chain', () {
    ReceivePort port = new ReceivePort();
    port.listen((msg) {
      print("Received msg + $msg");
      port.close();
    });
    Isolate.spawn(child, ['hi', port.sendPort]);
  });
}

This simple example shows one of the symptoms of the issue where the 're: $msg' is never printed.

Other examples sometimes run the child isolate code, but the reply messages to the reply port fails to send.

GaryQian · 2019-08-27T22:18:08Z

cc @jonahwilliams Not sure if you are the right person to ping on this, but remembered this bug existed!

iapicca · 2020-07-22T11:44:08Z

Hi @GaryQian
testing the code below with the latest master

code

import 'package:flutter_test/flutter_test.dart';
import 'dart:isolate';

child(args) {
  var msg = args[0];
  var reply = args[1];
  print("msg = $msg, reply = $reply");
  reply.send('re: $msg');
}

void main([args, port]) {
  test('message - reply chain', () {
    ReceivePort port =  ReceivePort();
    port.listen((msg) {
      print("Received msg + $msg");
      port.close();
    });
    Isolate.spawn(child, ['hi', port.sendPort]);
  });
}

logs

 nevercode@Nevercodes-Air  ~/Desktop/projects/master  flutter_master test                                                                                  ✔  2723  14:37:53
00:02 +1: All tests passed!

doctor

[✓] Flutter (Channel master, 1.21.0-2.0.pre.94, on Mac OS X 10.15.5 19F101, locale en-GB)
    • Flutter version 1.21.0-2.0.pre.94 at /Users/nevercode/development/flutter_master
    • Framework revision adc9dde3ba (12 hours ago), 2020-07-21 16:17:23 -0700
    • Engine revision 5a73d4dc25
    • Dart version 2.9.0 (build 2.9.0-21.0.dev 84e5eeaea4)


[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/nevercode/Library/Android/sdk
    • Platform android-29, build-tools 29.0.2
    • 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-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.5)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.5, Build version 11E608c
    • CocoaPods version 1.9.0

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

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 46.0.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.12.2

[✓] Connected device (4 available)
    • iPhone 11 Pro Max (mobile) • D6967F45-CB0F-4D4E-AFD5-278816A21CAE • ios            • com.apple.CoreSimulator.SimRuntime.iOS-13-5 (simulator)
    • macOS (desktop)            • macos                                • darwin-x64     • Mac OS X 10.15.5 19F101
    • Web Server (web)           • web-server                           • web-javascript • Flutter Tools
    • Chrome (web)               • chrome                               • web-javascript • Google Chrome 84.0.4147.89

• No issues found!

the issue seems to persist
Thank you

darshankawar · 2022-10-20T10:26:47Z

This still seems to be the case using latest stable and master versions:

dhs@Dhss-MacBook-Pro test_app % flutter test
00:02 +0: message - reply chain                                                                                                                                                          Shell: msg = hi, reply = SendPort
00:02 +1: message - reply chain                                                                                                                                                          
Received msg + re: hi
00:02 +1: All tests passed!

stable, master flutter doctor -v


[✓] Flutter (Channel stable, 3.3.5, on macOS 12.2.1 21D62 darwin-x64, locale
    en-GB)
    • Flutter version 3.3.5 on channel stable at
      /Users/dhs/documents/fluttersdk/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision d9111f6402 (10 hours ago), 2022-10-19 12:27:13 -0700
    • Engine revision 3ad69d7be3
    • Dart version 2.18.2
    • DevTools version 2.15.0

[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2

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

[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0

[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.

[✓] Flutter (Channel master, 3.5.0-6.0.pre.48, on macOS 12.2.1 21D62 darwin-x64,
    locale en-GB)
    • Flutter version 3.5.0-6.0.pre.48 on channel master at
      /Users/dhs/documents/fluttersdk/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 5a7224d14a (7 hours ago), 2022-10-17 12:25:57 +0800
    • Engine revision 59dea4cddd
    • Dart version 2.19.0 (build 2.19.0-312.0.dev)
    • DevTools version 2.18.0
    
[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2

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

[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0

[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.

GaryQian added the a: tests "flutter test", flutter_test, or one of our tests label Aug 28, 2018

zoechi added this to the Goals milestone Feb 13, 2019

zoechi added the tool Affects the "flutter" command-line tool. See also t: labels. label Feb 13, 2019

jmagman added this to Awaiting triage in Tools - "flutter test" review Jan 14, 2020

jonahwilliams removed the tool Affects the "flutter" command-line tool. See also t: labels. label May 23, 2020

jonahwilliams removed this from Awaiting triage in Tools - "flutter test" review May 23, 2020

kf6gpe added the P2 Important issues not at the top of the work list label May 29, 2020

iapicca added dependency: dart Dart team may need to help us framework flutter/packages/flutter repository. See also f: labels. labels Jul 1, 2020

iapicca added cp: 1.17 completed found in release: 1.21 Found to occur in 1.21 has reproducible steps The issue has been confirmed reproducible and is ready to work on and removed cp: 1.17 completed labels Jul 22, 2020

Hixie removed this from the None. milestone Aug 17, 2020

darshankawar added found in release: 3.5 Found to occur in 3.5 and removed found in release: 1.21 Found to occur in 1.21 labels Oct 20, 2022

flutter-triage-bot bot added team-framework Owned by Framework team triaged-framework Triaged by Framework team labels Jul 8, 2023

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flutter_test framework does not run isolates/handle isolate message sending properly #21093

flutter_test framework does not run isolates/handle isolate message sending properly #21093

GaryQian commented Aug 28, 2018 •

edited by zoechi

GaryQian commented Aug 27, 2019

iapicca commented Jul 22, 2020

darshankawar commented Oct 20, 2022

flutter_test framework does not run isolates/handle isolate message sending properly #21093

flutter_test framework does not run isolates/handle isolate message sending properly #21093

Comments

GaryQian commented Aug 28, 2018 • edited by zoechi

GaryQian commented Aug 27, 2019

iapicca commented Jul 22, 2020

darshankawar commented Oct 20, 2022

GaryQian commented Aug 28, 2018 •

edited by zoechi