karma-webpack: TypeError: Path must be a string. Received [ 'js/main.spec.js',

x｢wdm｣: wait until bundle finished: noop 03 09 2018 10:51:35.026:ERROR [karma]: TypeError: Path must be a string. Received [ 'js/main.spec.js', 'css/tiscc.min.css', 'js/main.spec.js.map', 'css/tiscc.min.css.map' ] at assertPath (path.js:28:11) at Object.join (path.js:1236:7) at Plugin.<anonymous> (/builds/tis/tis/tiscommandcenter/node_modules/karma-webpack/lib/karma-webpack.js:262:68) at Plugin.readFile (/builds/tis/tis/tiscommandcenter/node_modules/karma-webpack/lib/karma-webpack.js:281:5) at _combinedTickCallback (internal/process/next_tick.js:131:7) at process._tickCallback (internal/process/next_tick.js:180:9)

Operating System: Windows 10
Node Version: v8.11.3
NPM Version: 6.4.0
webpack Version: 4.17.1
karma-webpack Version: 3.0.2

Code

https://gist.github.com/casufi/f298bcab3f2f95a82616591446e380de

How Do We Reproduce?

About this issue

Original URL
State: closed
Created 6 years ago
Reactions: 24
Comments: 36 (4 by maintainers)

Commits related to this issue

fix web tests running on windows platform * by reverting broken "karma-webpack" 3.0.2=>3.0.1, https://github.com/webpack-contrib/karma-webpack/issues/350 — committed to vladimiry/ElectronMail by vladimiry 6 years ago
Updates karma to latest. Could not update karma-webpack to latest as it was not running because of an error: The "path" argument must be of type string. Received type object https://github.com/webpac... — committed to jitsi/lib-jitsi-meet by damencho 6 years ago
Updates karma to latest. Could not update karma-webpack to latest as it was not running because of an error: The "path" argument must be of type string. Received type object https://github.com/webpac... — committed to jitsi/lib-jitsi-meet by damencho 6 years ago
Updates karma to latest. Could not update karma-webpack to latest as it was not running because of an error: The "path" argument must be of type string. Received type object https://github.com/webpac... — committed to jitsi/lib-jitsi-meet by damencho 6 years ago
Set devtool to none to avoid https://github.com/webpack-contrib/karma-webpack/issues/350 Not sure yet of any side effects. — committed to jp7677/hellocoreclr by jp7677 6 years ago
fix web tests running on windows platform * by reverting broken "karma-webpack" 3.0.2=>3.0.1, https://github.com/webpack-contrib/karma-webpack/issues/350 — committed to devDefiWeb/electron-mail-app by devDefiWeb 6 years ago

Most upvoted comments

Note to maintainer: let us test your fixes first instead of putting out new buggy releases?

+10

thijstriemstra on Sep 7, 2018

@rythos42 3.0.0 is working fine for me.

nstepien on Sep 3, 2018

I’m still seeing the same issue on 3.0.4 (tests succeed on 3.0.0):

07 09 2018 12:30:23.322:ERROR [karma]: TypeError: Path must be a string. Received [ 'path/to/karma_index.bundle.js',
  'path/to/karma_index.bundle.js.map' ]
    at assertPath (path.js:28:11)
    at Object.join (path.js:1236:7)
    at Plugin.<anonymous> (path/to/node_modules/karma-webpack/lib/karma-webpack.js:266:68)
    at Plugin.readFile (path/to/karma-webpack/lib/karma-webpack.js:285:5)
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickCallback (internal/process/next_tick.js:180:9)
ℹ ｢wdm｣: Hash: 95085f23983f7eeef8e0
Version: webpack 4.17.2
Time: 22273ms
Built at: 2018-09-07 11:30:23

kirschre on Sep 7, 2018

the problem is it is this line:

https://github.com/webpack-contrib/karma-webpack/blob/d2f5a538d864e7b1f4bb431324de67be1ccbb51d/src/karma-webpack.js#L255

The problem is not line 255 itself, that is just where it occurs.

file is a file system path that is normalized to the operating system, meaning the path seperator on Windows is \ BUT the keys in this.outputs always uses the forward slash / regardless of the operating system. so the result of this.outputs[file] will always be undefined.

This will always be a problem on Windows. It will just happen to work on POSIX systems, but its fragile.

It appears this is a new issue. I was recently using 3.0.0 without any problems, when someone went to review my code "karma-webpack": "^3.0.0" in package.json resolved to 3.0.2 and the errors started.

npetruzzelli on Sep 6, 2018

Same issue in 3.0.5, so staying on 3.0.0. Mac and linux OSes

joseph-jja on Oct 4, 2018

Er, I’m still getting the same error reported by the OP in 3.0.3

uncleramsay on Sep 7, 2018

Confirming that this is still an issue on 3.0.5 running Ubuntu 16.04 and 18.04.

nronnei on Nov 16, 2018

This can be encountered if a preprocessor beforehand has already produced multiple outputs, too.

For example, sourcemaps preprocessing will result in ['foo.js', 'foo.js.map'].

Yep, setting ‘devtool’ to ‘none’ fixed this issue for me.

hans-pragt on Sep 12, 2018

@MayhemYDG oh damn, i’ll try that, cheers.

Update: same results, wtf

> wavesurfer.js@2.0.7 test /home/thijs/projects/wavesurfer.js
> karma start karma.conf.js

(node:4394) DeprecationWarning: Tapable.plugin is deprecated. Use new API on `.hooks` instead
    at Plugin.<anonymous> (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:109:14)
    at Array.forEach (<anonymous>)
    at Plugin (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:108:16)
    at invoke (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:75:15)
    at Array.instantiate (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:59:20)
    at get (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:48:43)
    at /home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:71:14
    at Array.map (<anonymous>)
    at Array.invoke (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:70:31)
    at Injector.get (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:48:43)
    at instantiatePreprocessor (/home/thijs/projects/wavesurfer.js/node_modules/karma/lib/preprocessor.js:50:20)
    at Array.forEach (<anonymous>)
    at createPreprocessor (/home/thijs/projects/wavesurfer.js/node_modules/karma/lib/preprocessor.js:68:20)
    at Array.invoke (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:75:15)
    at get (/home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:48:43)
    at /home/thijs/projects/wavesurfer.js/node_modules/di/lib/injector.js:71:14
ℹ ｢wdm｣: wait until bundle finished: noop
ℹ ｢wdm｣: wait until bundle finished: noop
ℹ ｢wdm｣: wait until bundle finished: noop
ℹ ｢wdm｣: wait until bundle finished: noop
06 09 2018 17:25:33.856:ERROR [karma]: TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string
    at assertPath (path.js:39:11)
    at Object.join (path.js:1158:7)
    at Plugin.<anonymous> (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:262:68)
    at Plugin.readFile (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:281:5)
    at process._tickCallback (internal/process/next_tick.js:176:11)
06 09 2018 17:25:33.858:ERROR [karma]: TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string
    at assertPath (path.js:39:11)
    at Object.join (path.js:1158:7)
    at Plugin.<anonymous> (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:262:68)
    at Plugin.readFile (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:281:5)
    at process._tickCallback (internal/process/next_tick.js:176:11)
06 09 2018 17:25:33.859:ERROR [karma]: TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string
    at assertPath (path.js:39:11)
    at Object.join (path.js:1158:7)
    at Plugin.<anonymous> (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:262:68)
    at Plugin.readFile (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:281:5)
    at process._tickCallback (internal/process/next_tick.js:176:11)
06 09 2018 17:25:33.859:ERROR [karma]: TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string
    at assertPath (path.js:39:11)
    at Object.join (path.js:1158:7)
    at Plugin.<anonymous> (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:262:68)
    at Plugin.readFile (/home/thijs/projects/wavesurfer.js/node_modules/karma-webpack/lib/karma-webpack.js:281:5)
    at process._tickCallback (internal/process/next_tick.js:176:11)
ℹ ｢wdm｣: 
ℹ ｢wdm｣: Compiled successfully.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! wavesurfer.js@2.0.7 test: `karma start karma.conf.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the wavesurfer.js@2.0.7 test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

@thijstriemstra hope it helps

Fixed “path” error with var webpackConfig = require('./build-config/webpack.prod.main.js'); webpackConfig.devtool = 'none'; in karma.conf.js

DeprecationWarning is gone with "karma-webpack": "^4.0.0-rc.2"

aburai on Nov 17, 2018

Or revert regressions. 🤔

nstepien on Sep 7, 2018

@thijstriemstra I get the same error on karma-webpack 3.0.2. Make sure you install version 3.0.0 exactly. Delete your node_modules and lock files, re-install your npm dependencies, and retry.

nstepien on Sep 7, 2018

Will get a fix out asap

ryanclark on Sep 6, 2018

This can be encountered if a preprocessor beforehand has already produced multiple outputs, too.

For example, sourcemaps preprocessing will result in ['foo.js', 'foo.js.map'].

43081j on Sep 6, 2018