karma-runner/karma

Chrome occasionally does not receive any messages before default 10s timeout - Windows 10

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#2790 opened on Jul 28, 2017

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 (3 comments) (1 reaction) (0 assignees)JavaScript (11,918 stars) (1,703 forks)batch import
help wantedneeds: investigation

Description

Expected behaviour

Chrome should receive messages from Karma during test suite. Once received tests should run.

Actual behaviour

Server is started with unlimited concurrency. Chrome is started. Chrome then disconnects with the results: Disconnected (1 times), because no message in 10000 ms.

Environment Details

Windows 10 Chrome Version 59.0.3071.115 (Official Build) (64-bit) Karma version: 1.7.0

config.set({
  frameworks: ['jasmine'],
  files: [..],
  preprocessors: [...],
  reporters: ['progress', 'coverage', 'tfs'],
  port: 9876,
  autoWatch: true,
  browsers: ['Chrome'],
  singleRun: false,
  concurrency: Infinity,
  // reporters...
});

Relevant Project dependencies:

  ...
   "jasmine-core": "2.5.2",
    "karma": "1.7.0",
    "karma-chrome-launcher": "2.1.1",
    "karma-coverage": "^1.1.1",
    "karma-firefox-launcher": "1.0.1",
    "karma-jasmine": "1.1.0",
    "karma-ng-html2js-preprocessor": "^1.0.0",
    "karma-phantomjs-launcher": "1.0.4",
    "karma-spec-reporter": "0.0.31",
    "karma-tfs-reporter": "^1.0.0"
  ...

Steps to reproduce the behaviour

  1. Create a project with the above dependencies and set up a basic gulp runner that runs unit tests using chrome and Karma.
  2. Run tests
  3. Watch for occasional failures.
  4. Drink heavily after work.

Additional Description:

I'm using Karma and Gulp to run unit tests in a Windows 10 TFS environment. Intermittently my builds are failing due to the aforementioned error. The stack trace that I am seeing is attached. I think there might be an issue with Chrome child processes or something not closing or perhaps a breaking change between Chrome versions that recently popped up, but I'm not sure. stack trace.txt

Contributor guide

Tech stack
javascriptnodejs
Domain
testingtooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
familiarity with KarmaChrome debuggingWindows environment
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue is an intermittent Chrome disconnection on Windows 10 with Karma 1.7.0. Investigate the browser socket.js file in the Karma repository for message timeout handling. Check if setting concurrency to Infinity causes a race condition. Review Chrome launcher source for child process management, especially on Windows. Look for related Chromium changes around Chrome 59 that might affect WebSocket connections.