Karma 1.6 first-matcher (file-list fix) update is hard to debug

[steveworkman]

Expected behaviour

Matchers in the matchers list bring back files according to their pattern. When the file is the first one in the list, it should be brough back.

Actual behaviour

Since 1.6 with this change for file-list some of my files aren't returned

Environment Details

OS X 10.11, PhantomJS browser

• Karma version (output of karma --version): 1.6
• Relevant part of your karma.config.js file

V1.5 (working)
// list of files / patterns to load in the browser

files: [
	{pattern: (min ? 'min/' : '') + 'modules/**/*.js',		included: false},
	{pattern: 'modules/**/*.test.js',					included: false},
	{pattern: 'resources/karma.preconf.js',			included: true},
	{pattern: (min ? 'min/' : '') + 'core.js',				included: true},
	'libs/jquery.js', // Must be included before jasmine-jquery or it doesn't work
	{pattern: 'resources/vendor/*.js'},
	{pattern: 'resources/karma.main.js',				included: true},
	{pattern: 'modules/**/tests/fixtures/*.html',			included: false}
],

Output:

Running "karma:desktop" (karma) task
24 04 2017 15:50:01.090:INFO [karma]: Karma v1.5.0 server started at http://0.0.0.0:9876/

v1.6 (not working)

// list of files / patterns to load in the browser
files: [
	'libs/jquery.js', // Must be included before jasmine-jquery or it doesn't work
	{pattern: (min ? 'min/' : '') + 'modules/**/*.js',		included: false},
	{pattern: 'modules/**/*.test.js',					included: false},
	{pattern: 'resources/karma.preconf.js',			included: true},
	{pattern: (min ? 'min/' : '') + 'core.js',				included: true},
	{pattern: 'resources/vendor/*.js'},
	{pattern: 'resources/karma.main.js',				included: true},
	{pattern: 'modules/**/tests/fixtures/*.html',			included: false}
],

Output:

Running "karma:desktop" (karma) task
24 04 2017 15:46:59.168:WARN [watcher]: All files matched by "/...../yelldotcom/src/main/ftl/default/_yframe/libs/jquery.js" were excluded or matched by prior matchers.
24 04 2017 15:46:59.170:WARN [watcher]: All files matched by "/...../yelldotcom/src/main/ftl/default/_yframe/modules/**/*.test.js" were excluded or matched by prior matchers.
24 04 2017 15:47:01.898:INFO [karma]: Karma v1.6.0 server started at http://0.0.0.0:9876/

Part of the problem here is that I have no idea how to find out what matcher is matching this. It would be really helpful if the warning could list out the matchers that it was matched for so that I can re-order it or change those matchers.

Steps to reproduce the behaviour

[clintonb]

I have the same issue. This might be related to the changes in #2620. My attempts to install the package from the repo, with the commits before this one, fail due to static/karma.js being absent.

[maksimr]

@clintonb @steveworkman could you create repository or gist which reproduce the problem?
It will be very valuable

Thanks

[clintonb]

Here you go: https://github.com/edx/ecommerce/tree/clintonb/karma-fail-demo