"config.files.map is not a function" when passing --files option

Hi, It seems I am unable to instruct Karma to only run a particular file.

Is this not possible anymore (I saw a reference to this having been possible on Stack Overflow)?

$ karma run karma.conf.js --files=new Array\("tests/unit/frontend/specs/timeLeftSpec.js"\)

[2015-11-30 10:20:50.784] [DEBUG] config - Loading config /Users/vs/Kod/myproject/karma.conf.js
/Users/vs/Kod/myproject/node_modules/karma/lib/config.js:107
  config.files = config.files.map(createPatternObject).map(createPatternMapper(basePathResolve));
                              ^

TypeError: config.files.map is not a function
    at normalizeConfig (/Users/vs/Kod/myproject/node_modules/karma/lib/config.js:107:31)
    at Object.parseConfig (/Users/vs/Kod/myproject/node_modules/karma/lib/config.js:293:10)
    at Object.exports.run (/Users/vs/Kod/myproject/node_modules/karma/lib/runner.js:30:16)
    at Object.<anonymous> (/usr/local/share/npm/lib/node_modules/karma/bin/karma:22:39)
    at Module._compile (module.js:434:26)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:475:10)
    at startup (node.js:117:18)

I imagine using this for allowing my IDE (PhpStorm) to run the Karma test for a file (in the IDE) whenever a test/implementation file changes.

[joallard]

Banging my head on the wall for a few hours of this now, I don’t get why karma needs to be this user-hostile to running a single test. Makes TDD a true pain edit: excruciating.

[dignifiedquire]

Banging my head on the wall for a few hours of this now, I don’t get why karma needs to be this user-hostile to running a single test. Makes TDD a true pain edit: excruciating.

Comments like this are pretty maintainer-hostile. So if you need this so badly why not create a good PR with tests to solve the issue?