Successful tests are marked as failed because of DISCONNECTED

Chrome 51.0.2704 (Windows 10 0.0.0): Executed 21 of 21 DISCONNECTED (14.456 secs / 4.149 secs)
Firefox 47.0.0 (Windows 10 0.0.0): Executed 21 of 21 DISCONNECTED (14.419 secs / 4.128 secs)
Safari 9.0.0 (Mac OS X 10.11.0): Executed 21 of 21 SUCCESS (4.996 secs / 4.118 secs)
Safari 8.0.8 (Mac OS X 10.10.5): Executed 21 of 21 SUCCESS (4.349 secs / 4.079 secs)
Edge 13.10586.0 (Windows 10 0.0.0): Executed 21 of 21 DISCONNECTED (14.333 secs / 4.073 secs)
IE 11.0.0 (Windows 8.1 0.0.0): Executed 21 of 21 DISCONNECTED (14.91 secs / 4.05 secs)
IE 10.0.0 (Windows 8 0.0.0): Executed 21 of 21 SUCCESS (4.308 secs / 4.051 secs)
IE 9.0.0 (Windows 7 0.0.0): Executed 21 of 21 SUCCESS (4.286 secs / 4.029 secs)
Mobile Safari 7.0.0 (iOS 7.1.0): Executed 21 of 21 SUCCESS (4.312 secs / 4.051 secs)

While running the tests, I often see something like this:

15 07 2016 10:26:30.397:WARN [IE 10.0.0 (Windows 8 0.0.0)]: Disconnected (1 times), because no message in 10000 ms.
IE 10.0.0 (Windows 8 0.0.0) ERROR
  Disconnected, because no message in 10000 ms.
15 07 2016 10:26:30.397:INFO [karma]: Restarting IE 10.0.0 (Windows 8 0.0.0) (1 of 3 attempts)

But IE tests has already passed before this message.

Let me know how I can provide more information.

This is my dependencies:

├── babel-cli@6.10.1
├── babel-core@6.10.4
├── babel-eslint@6.1.0
├── babel-loader@6.2.4
├── babel-plugin-__coverage__@11.0.0
├── babel-preset-es2015@6.9.0
├── babel-preset-es2015-loose@7.0.0
├── babel-preset-react@6.11.1
├── browser-sync@2.13.0
├── classnames@2.2.5
├── element-resize-detector@1.1.5
├── eslint@2.13.1
├── eslint-config-rackt@1.1.1
├── eslint-plugin-react@5.2.2
├── gulp@3.9.1
├── gulp-debug@2.1.2
├── gulp-watch@4.3.8
├── invariant@2.2.1
├── istanbul-combine@0.3.0
├── jasmine-core@2.4.1
├── karma@1.1.1
├── karma-babel-preprocessor@6.0.1
├── karma-chrome-launcher@1.0.1
├── karma-coverage@1.1.0
├── karma-jasmine@1.0.2
├── karma-sauce-launcher@1.0.0
├── karma-sourcemap-loader@0.3.7
├── karma-spec-reporter@0.0.26
├── karma-webpack@1.7.0
├── lodash@4.13.1
├── onchange@2.5.0
├── react@15.1.0
├── react-dom@15.1.0
├── rimraf@2.5.2
├── tslint@3.13.0
├── typescript@1.8.10
├── typings@1.3.1
├── webpack@1.13.1
└── yargs@4.8.0

[cecilia-sanare]

So after a few days of messing around, I’ve come to realize that various browsers will fail to stop if you use any form of code coverage.

isparta-loader, babel-plugin-istanbul, etc. all cause Edge 14, Safari 9, and Safari 8 to hang on Sauce Labs.

[aore]

This error is still happening even though I’ve removed my code coverage tools. My errors look like this:

Chrome 55.0.2883 (Mac OS X 10.9.5): Executed 4 of 86 SUCCESS (0.432 secs / 0.437 secs)
03 04 2017 11:37:48.491:INFO [launcher]: Starting browser chrome 56 (OS X 10.9) on SauceLabs
03 04 2017 11:37:58.443:WARN [Chrome 55.0.2883 (Mac OS X 10.9.5)]: Disconnected (1 times), because no message in 10000 ms.
Chrome 55.0.2883 (Mac OS X 10.9.5) ERROR
  Disconnected, because no message in 10000 ms.
Chrome 55.0.2883 (Mac OS X 10.9.5): Executed 4 of 86 DISCONNECTED (10.44 secs / 0.437 secs)
03 04 2017 11:37:58.450:ERROR [reporter.sauce]: ✖ Test Disconnected

With concurrency: 1, tests in Chrome 55 pass, then Chrome 56 starts, and then Chrome 55 returns an error due to disconnecting. Similarly, Chrome 54 has a disconnect error after its tests pass and Chrome 55 starts, and Chrome 56 passes with no disconnect error. Chrome 55 should disconnect after it passes, right? Why is this an error?

I’m testing Chrome 54-56. When I set concurrency: 5, only Chrome 56 fails due to disconnection. Odd behavior.

Does anyone know other solutions?