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 to install them are as project dependencies in your 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 to install a plugin is:

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

Loading Plugins #

By default, Karma loads all sibling NPM modules which have a name starting with 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: [
  // Karma will require() these plugins
  'karma-jasmine',
  'karma-chrome-launcher'
  // inlined plugins
  {'framework:xyz': ['factory', factoryFn]},
  require('./plugin-required-from-config')
]

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