Plugins

Karma can be easily extended through plugins. In fact, all the existing preprocessors, reporters, browser launchers and frameworks are also plugins.

Installation #

Karma plugins are NPM modules, so the recommended way is to keep all the plugins your project requires in package.json:

{
  "devDependencies": {
    "karma": "~0.10",
    "karma-mocha": "~0.0.1",
    "karma-growl-reporter": "~0.0.1",
    "karma-firefox-launcher": "~0.0.1"
  }
}

Therefore, a simple way how to install a plugin is

npm install karma-<plugin name> --save-dev

Loading Plugins #

By default, Karma loads all NPM modules that are siblinks to it and their name matches karma-*.

You can also explicitly list plugins you want to load via the plugins configuration setting. The configuration value can either be a string (module name), which will be required by Karma, or an object (inlined plugin).

plugins: [
  // these plugins will be require() by Karma
  'karma-jasmine',
  'karma-chrome-launcher'

  // inelined plugins
  {'framework:xyz', ['factory', factoryFn]},
  require('./plugin-required-from-config')
]

There are already many existing plugins. Of course, you write your own plugins too!