Allow browserDisconnectTolerance to be set in non-singleRun mode.

[dtinth]

We’re encountering a problem where sometimes Karma just disconnects and stops running tests until we restart Karma manually.

We found that some of our JavaScript code intermittently gets stuck when running tests — that Karma considers it a time out. One such example is an infinite loop in the code.

Looking at other issues (#598, #1514) suggests adding browserDisconnectTolerance. I’ve tried that and several other options to no avail.

From further source code inspection, in 19590e1 it turns out that browserDisconnectTolerance is only active in singleRun mode. This pull request makes browserDisconnectTolerance work in non-singleRun mode.

Test case

Here’s a test case to verify that my patch works:

test.js

This test will get stuck in an infinite loop with 75% chance.

describe('example', function () {
  it('ok1', function () { })
  it('ok2', function () { })
  it('bad1', function () {
    if (Math.random() > 0.5) for (;;) ;
  })
  it('bad2', function () {
    if (Math.random() > 0.5) for (;;) ;
  })
  it('ok3', function () { })
})

karma.conf.js

Sets a ridiculously high amount of retries.

module.exports = function (config) {
  config.set({
    basePath: '',
    frameworks: ['mocha'],
    files: [
      'test.js'
    ],
    reporters: [ 'progress' ],
    port: 9988,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: [ 'PhantomJS' ],
    browserDisconnectTolerance: 99999999999999999999999999999999999999999999999,
    retryLimit: 999999999999999999999999999999999999999999999999999999999999999,
    plugins: [
      'karma-mocha',
      'karma-phantomjs-launcher',
    ],
    singleRun: false,
  })
}

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[dtinth]

My employer has signed the CLA for me.

On a related note, new version of eslint-config-standard broke the builds, because this repo gets a minor version bump when a new major version of standard is released. I believe that this problem is out of the scope of this pull request.

[dignifiedquire]

Thanks, could you please update your commit message to follow our convention: http://karma-runner.github.io/0.13/dev/git-commit-msg.html

[dtinth]

Thanks for your reply. Will do it tomorrow.

[googlebot]

CLAs look good, thanks!

[dtinth]

I’ll put a draft commit message here in case you would like to comment on it before I do the actual amendment tomorrow:

fix(web-server): Restart disconnected browser in non-singleRun mode.

Allow browserDisconnectTolerance config option to be set in non-singleRun mode.

In some cases, the browser would get stuck in an infinite loop (e.g. because of
a faulty code/test). This blocks browser’s event loop, preventing it from
reporting back to Karma. Karma then considers the browser ‘DISCONNECTED’.

Prior to this commit, the `browserDisconnectTolerance` option will only apply
in singleRun mode. In above scenario, the end-user must restart Karma to
continue running tests inside Karma-managed browsers. This commit fixes this
problem by always honoring the aforementioned option.

I marked this as a “fix” because the configuration docs did not mention that this option will not apply in non-singleRun mode. Please let me know if it needs changing.

[dignifiedquire]

Thanks, commit message looks good to me. Can you please also rebase onto latest master as that should make CI happy again

[dtinth]

Thanks for the feedback. Rebased. 😉

[dignifiedquire]

Thanks