### Install Karma plugins and initialize configuration

Source: https://karma-runner.github.io/6.4/plus/emberjs.html

Install the required Karma plugins and generate a configuration file. The npm install commands add the QUnit adapter and the Ember preprocessor, and 'karma init' walks through the basic setup.

```bash
npm install karma-qunit --save-dev

```

```bash
npm install karma-ember-preprocessor --save-dev

```

```bash
karma init

```

--------------------------------

### server.start()

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Starts the Karma server. This method is equivalent to the `karma start` command.

```APIDOC
## server.start()

### Description
Starts the Karma server, equivalent to running `karma start` from the command line.

### Method
start

### Usage
```
server.start()
```
```

--------------------------------

### Directory tree example

Source: https://karma-runner.github.io/6.4/plus/requirejs.html

Shows the example project structure with karma.conf.js, test-main.js, and other files.

```bash
$ tree
.
|-- index.html
|-- karma.conf.js
|-- lib
|   |-- jquery.js
|   |-- require.js
|   `-- underscore.js
|-- src
|   |-- app.js
|   `-- main.js
`-- test
    |-- appSpec.js
    `-- test-main.js

3 directories, 9 files

```

--------------------------------

### Start Karma server

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Starts the Karma server, equivalent to running `karma start` from the command line.

```javascript
server.start()

```

--------------------------------

### Run Karma with PhantomJS

Source: https://karma-runner.github.io/6.4/plus/cloud9.html

Installs the PhantomJS launcher plugin and starts Karma with PhantomJS as the browser.

```bash
# Install the PhantomJS plugin:
$ npm install karma-phantomjs-launcher

# Start Karma:
$ karma start --browsers PhantomJS

```

--------------------------------

### Install karma-cli

Source: https://karma-runner.github.io/6.4/about/migration.html

Install the command line interface to use the karma command.

```bash
npm install -g karma-cli

```

--------------------------------

### Start Karma with a configuration file

Source: https://karma-runner.github.io/6.4/intro/configuration.html

Starts Karma using the specified configuration file. If no file is given, Karma looks for `karma.conf.js` or `karma.conf.coffee` in the current directory.

```bash
# Start Karma using your configuration:
$ karma start my.conf.js

```

--------------------------------

### Initialize Karma with karma init

Source: https://karma-runner.github.io/6.4/plus/requirejs.html

Command to start the interactive Karma configuration wizard.

```bash
$ karma init

```

--------------------------------

### Configure CoffeeScript preprocessor in Karma config

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Example configuration file that sets up the 'coffee' preprocessor for CoffeeScript files. This is the typical usage after installing the plugin.

```javascript
module.exports = function(config) {
  config.set({
    preprocessors: {
      '**/*.coffee': ['coffee']
    }
  });
};

```

--------------------------------

### Install karma-firefox-launcher

Source: https://karma-runner.github.io/6.4/config/browsers.html

Install the Firefox launcher plugin via npm before adding Firefox to the browsers array.

```bash
# Install the launcher first with npm:
$ npm install karma-firefox-launcher --save-dev

```

--------------------------------

### Install karma-teamcity-reporter

Source: https://karma-runner.github.io/6.4/plus/teamcity.html

Installs the karma-teamcity-reporter package as a development dependency using npm.

```bash
npm i --save-dev karma-teamcity-reporter

```

--------------------------------

### Upgrade to constructor-based server API (after)

Source: https://karma-runner.github.io/6.4/about/changelog.html

New way to start the Karma server after version 0.13.0. Use the Server constructor and call start() on the instance.

```javascript
var Server = require(‘karma’).Server
var server = new Server(config, done)
server.start()

```

--------------------------------

### Install karma-cli globally

Source: https://karma-runner.github.io/6.4/intro/installation.html

Installs karma-cli globally to run Karma from the command line; required on Windows.

```bash
$ npm install -g karma-cli

```

--------------------------------

### Preprocessors execution order example

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Shows a simple preprocessors config where 'a' is executed before 'b' for '*.js' files.

```javascript
preprocessors: {
  '*.js': ['a', 'b']
}

```

--------------------------------

### Start Karma test runner

Source: https://karma-runner.github.io/6.4/plus/requirejs.html

Run this command to start Karma and execute tests. If not configured to watch files, use 'karma run' to trigger manually.

```bash
$ karma start

```

--------------------------------

### Configure package.json for Karma with PhantomJS

Source: https://karma-runner.github.io/6.4/plus/semaphore.html

Example package.json configuration for running Karma tests with PhantomJS on Semaphore. Includes the karma devDependency and a test script that starts Karma in single-run mode with PhantomJS.

```json
// ...snip...
"devDependencies": {
  "karma": "~0.10"
},
// ...snip...
"scripts": {
   "test": "./node_modules/.bin/karma start --single-run --browsers PhantomJS"
}
// ...snip...

```

--------------------------------

### httpsServerOptions example

Source: https://karma-runner.github.io/6.4/config/configuration-file.html

Configures HTTPS server options with key and cert read from files. Use this to enable HTTPS in Karma.

```javascript
httpsServerOptions: {
  key: fs.readFileSync('server.key', 'utf8'),
  cert: fs.readFileSync('server.crt', 'utf8')
},
```

--------------------------------

### Partial order preprocessor example

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Shows a config where 'a' runs first, 'd' runs last, but 'b' and 'c' order is arbitrary.

```javascript
preprocessors: {
  '*.js': ['a', 'b', 'c'],
  'a.*': ['c', 'b', 'd']
}

```

--------------------------------

### Install karma-coffee-preprocessor

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Install the CoffeeScript preprocessor plugin via npm. This is required before using the 'coffee' preprocessor.

```bash
# Install it first with npm
$ npm install karma-coffee-preprocessor --save-dev

```

--------------------------------

### Karma files configuration complete example

Source: https://karma-runner.github.io/6.4/config/files.html

Complete example of the `files` configuration array in a Karma config file. Shows detailed patterns with options like `watched`, `served`, `included`, and `nocache`, plus a simple string pattern equivalent to `{pattern: 'test/unit/*.spec.js', watched: true, served: true, included: true}`. Note that with the html2js preprocessor, HTML files are referenced as `window.__html__['compiled/index.html']`.

```javascript
files: [

  // Detailed pattern to include a file. Similarly other options can be used
  { pattern: 'lib/angular.js', watched: false },
  // Prefer to have watched false for library files. No need to watch them for changes

  // simple pattern to load the needed testfiles
  // equal to {pattern: 'test/unit/*.spec.js', watched: true, served: true, included: true}
  'test/unit/*.spec.js',

  // this file gets served but will be ignored by the watcher
  // note if html2js preprocessor is active, reference as `window.__html__['compiled/index.html']`
  {pattern: 'compiled/index.html', watched: false},

  // this file only gets watched and is otherwise ignored
  {pattern: 'app/index.html', included: false, served: false},

  // this file will be served on demand from disk and will be ignored by the watcher
  {pattern: 'compiled/app.js.map', included: false, served: true, watched: false, nocache: true}
],
```

--------------------------------

### Configure .codio file for Karma

Source: https://karma-runner.github.io/6.4/plus/codio.html

Configuration for the Codio project's .codio file. It defines the Run and Preview buttons: 'Karma Start' runs 'karma start --no-browsers', 'Karam Run' runs 'karma run', and 'Karma Preview' opens 'http://{{domain}}:8080'. Note the typo 'Karam Run' in the source. The port can be changed, but must match the port in karma.conf.js.

```json
{
// Configure your Run and Preview buttons here.

// Run button configuration
  "commands": {
    "Karma Start": "karma start --no-browsers"
    "Karam Run": "karma run"
  },

// Preview button configuration
  "preview": {
    "Karma Preview": "http://{{domain}}:8080"
  }
}

```

--------------------------------

### Install a Karma plugin with npm

Source: https://karma-runner.github.io/6.4/config/plugins.html

Install a Karma plugin from npm and save it as a dev dependency. Replace <plugin name> with the actual plugin name.

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

```

--------------------------------

### Install Karma and plugins locally

Source: https://karma-runner.github.io/6.4/intro/installation.html

Installs Karma and the plugins karma-jasmine, karma-chrome-launcher, and jasmine-core as devDependencies in the current project directory.

```bash
# Install Karma:
$ npm install karma --save-dev

# Install plugins that your project needs:
$ npm install karma-jasmine karma-chrome-launcher jasmine-core --save-dev

```

--------------------------------

### Contradictory preprocessor order example

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Shows a config with contradictory orders; Karma arbitrarily picks one list to prioritize.

```javascript
preprocessors: {
  '*.js': ['a', 'b'],
  'a.*': ['b', 'a']
}

```

--------------------------------

### Install latest Karma

Source: https://karma-runner.github.io/6.4/about/migration.html

Run this command in your project directory to install the latest version of Karma and update package.json.

```bash
cd <path-to-your-project>
npm install karma --save-dev

```

--------------------------------

### Simple QUnit test example

Source: https://karma-runner.github.io/6.4/plus/emberjs.html

A simple QUnit test example that asserts equality. This test is added to the test files and run with Karma.

```javascript
test('one should equal one', function() {
    equal(1, 1, 'error: one did not equal one');
});

```

--------------------------------

### runner.run(options, [callback=process.exit])

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Documentation for the runner.run method, including usage examples and event handling.

```APIDOC
## runner.run(options, [callback=process.exit])

### Description
Runs Karma tests, equivalent to the `karma run` command. Returns an EventEmitter that emits a `progress` event with reporter output.

### Method
runner.run

### Parameters
- **options** (Object) - Required - Configuration options, typically a parsed Karma config object or an object with a `port` property.
- **callback** (Function) - Optional - Callback function that receives the exit code as the first argument and an optional error code as the second argument.

### Returns
- **EventEmitter** - Emits a `progress` event with a `Buffer` of reporter output.

### Usage Example (Deprecated)
```javascript
var runner = require('karma').runner
runner.run({port: 9876}, function(exitCode) {
  console.log('Karma has exited with ' + exitCode)
  process.exit(exitCode)
})
```

### Usage Example (New Behavior)
```javascript
const karma = require('karma')

karma.config.parseConfig(
  null,
  { port: 9876 },
  { promiseConfig: true, throwErrors: true }
).then(
  (karmaConfig) => {
    karma.runner.run(karmaConfig, function doneCallback(exitCode, possibleErrorCode) {
      console.log('Karma has exited with ' + exitCode)
      process.exit(exitCode)
    })
  },
  (rejectReason) => { /* respond to the rejection reason error */ }
);
```

### Events
- **progress** - Emitted with a `Buffer` of reporter output. Example:
```javascript
runner.run({port: 9876}).on('progress', function(data) {
  process.stdout.write(data)
})
```
```

--------------------------------

### Start Karma without browsers

Source: https://karma-runner.github.io/6.4/plus/cloud9.html

Starts Karma without launching any browsers, allowing manual capture from a local browser.

```bash
# Start Karma without browsers:
$ karma start --no-browsers

```

--------------------------------

### Install Karma with NPM

Source: https://karma-runner.github.io/6.4/about/versioning.html

Adds Karma as a development dependency using npm.

```bash
$ npm --save-dev install karma

```

--------------------------------

### Karma Server Usage

Source: https://karma-runner.github.io/6.4/about/changelog.html

Shows the canonical way to start a Karma server after the removal of deprecated static methods. Use this instead of the removed `require('karma').server.start()` and `require('karma').Server.start()` variants.

```javascript
const { Server } = require('karma');
const server = new Server();
server.start();
```

--------------------------------

### Event: 'run_start'

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Event emitted when a test run starts.

```APIDOC
## Event: 'run_start'

### Description
Emitted when a test run starts.

### Arguments
- **browsers** (array) - A collection of browser instances on which tests are executed.
```

--------------------------------

### Configure Travis with Firefox (Trusty and below)

Source: https://karma-runner.github.io/6.4/plus/travis.html

Update .travis.yml to set up a virtual screen for Firefox on Trusty and below. This exports DISPLAY and starts xvfb.

```yaml
language: node_js
node_js:
  - "4"
before_script:
  - export DISPLAY=:99.0
  - sh -e /etc/init.d/xvfb start

```

--------------------------------

### Install Karma with Yarn

Source: https://karma-runner.github.io/6.4/about/versioning.html

Adds Karma as a development dependency using yarn.

```bash
$ yarn add --dev karma

```

--------------------------------

### Upgrade to constructor-based server API (before)

Source: https://karma-runner.github.io/6.4/about/changelog.html

Old way to start the Karma server before version 0.13.0. The public API changed to a constructor form, so this code must be updated.

```javascript
var server = require(‘karma’).server
server.start(config, done)

```

--------------------------------

### Run Karma locally

Source: https://karma-runner.github.io/6.4/intro/installation.html

Runs Karma using the locally installed binary in node_modules.

```bash
# Run Karma:
$ ./node_modules/karma/bin/karma start

```

--------------------------------

### stopper.stop(options, [callback=process.exit])

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Documentation for the stopper.stop method, including usage examples and callback behavior.

```APIDOC
## stopper.stop(options, [callback=process.exit])

### Description
Signals a running Karma server to stop, equivalent to the `karma stop` command.

### Method
stopper.stop

### Parameters
- **options** (Object) - Required - Configuration options, typically a parsed Karma config object or an object with a `port` property.
- **callback** (Function) - Optional - Callback function that receives the exit code as the first argument and an optional error code as the second argument.

### Usage Example (Deprecated)
```javascript
var stopper = require('karma').stopper
stopper.stop({port: 9876}, function(exitCode) {
  if (exitCode === 0) {
    console.log('Server stop as initiated')
  }
  process.exit(exitCode)
})
```

### Usage Example (New Behavior)
```javascript
const karma = require('karma')

karma.config.parseConfig(
  null,
  { port: 9876 },
  { promiseConfig: true, throwErrors: true }
).then(
  (karmaConfig) => {
    karma.stopper.stop(karmaConfig, function doneCallback(exitCode, possibleErrorCode) {
      if (exitCode === 0) {
        console.log('Server stop as initiated')
      }
      process.exit(exitCode)
    })
  },
  (rejectReason) => { /* respond to the rejection reason error */ }
);
```
```

--------------------------------

### mime configuration example

Source: https://karma-runner.github.io/6.4/config/configuration-file.html

Redefines default file extension to MIME-type mappings. Set property name to the required MIME type and provide an array of extensions (without dots) as its value.

```javascript
mime: {
   'text/x-typescript': ['ts','tsx']
   'text/plain' : ['mytxt']
}
```

--------------------------------

### Define custom launchers

Source: https://karma-runner.github.io/6.4/config/browsers.html

Define custom launchers with base browser and flags. This example shows a Chrome launcher without security and a SauceLabs launcher for Windows.

```javascript
customLaunchers: {
  chrome_without_security: {
    base: 'Chrome',
    flags: ['--disable-web-security']
  },
  sauce_chrome_win: {
    base: 'SauceLabs',
    browserName: 'chrome',
    platform: 'windows'
  }
}

```

--------------------------------

### proxies configuration example

Source: https://karma-runner.github.io/6.4/config/configuration-file.html

Defines a map of path-proxy pairs. The proxy can be a target URL/path string or an object with 'target' and 'changeOrigin' options. The 'changeOrigin' option overrides the Host header using the target's host, defaulting to false.

```javascript
proxies: {
  '/static': 'http://gstatic.com',
  '/web': 'http://localhost:9000',
  '/img/': '/base/test/images/',
  '/proxyfied': {
    'target': 'http://myserver.localhost',
    'changeOrigin': true
  }
},
```

--------------------------------

### Remove global karma package

Source: https://karma-runner.github.io/6.4/about/migration.html

If you have the karma package installed globally, remove it before installing the CLI.

```bash
npm remove -g karma

```

--------------------------------

### Configure coffeePreprocessor options

Source: https://karma-runner.github.io/6.4/config/preprocessors.html

Shows how to set options for the 'coffee' preprocessor, such as 'bare: false'.

```javascript
coffeePreprocessor: {
  options: {
    bare: false
  }
}

```

--------------------------------

### hello-plugin.js - Declare a framework plugin

Source: https://karma-runner.github.io/6.4/dev/plugins.html

Defines a factory function that logs 'Hello, world!' when instantiated. The plugin exports a DI token 'framework:hello' mapped to the factory, so Karma instantiates it when the plugin is activated.

```javascript
// hello-plugin.js

// A factory function for our plugin, it will be called, when Karma needs to
// instantiate a plugin. Normally it should return an instance of the service
// conforming to the API requirements of the plugin type (more on that below),
// but for our simple example we don't need any service and just print 
// a message when function is called.
function helloFrameworkFactory() {
  console.log('Hello, world!')
}

module.exports = {
  // Declare the plugin, so Karma knows that it exists.
  // 'factory' tells Karma that it should call `helloFrameworkFactory`
  // function and use whatever it returns as a service for the DI token
  // `framework:hello`.
  'framework:hello': ['factory', helloFrameworkFactory]
};
```

```javascript
// karma.conf.js

module.exports = (config) => {
  config.set({
    plugins: [
      require('./hello-plugin')
    ],
    // Activate our plugin by specifying its unique name in the 
    // corresponding configuration key.
    frameworks: ['hello']
  })
}
```

--------------------------------

### Example commit message

Source: https://karma-runner.github.io/6.4/dev/git-commit-msg.html

Example of a properly formatted commit message with a fix type, scope, subject, body, and footer referencing an issue.

```text
fix(middleware): ensure Range headers adhere more closely to RFC 2616

Add one new dependency, use `range-parser` (Express dependency) to compute
range. It is more well-tested in the wild.

Fixes #2310

```

--------------------------------

### Ember bootstrap file to delay Karma test start

Source: https://karma-runner.github.io/6.4/plus/emberjs.html

Bootstrap file to prevent Karma from starting tests until the Ember application has finished initialization. It overrides __karma__.loaded, sets up testing helpers, and uses an initializer to start Karma only once, guarding against repeated calls due to Ember.reset() in test teardown.

```javascript
__karma__.loaded = function() {};

App.setupForTesting();
App.injectTestHelpers();

//this gate/check is required given that standard practice in Ember tests to is to call
//Ember.reset() in the afterEach/tearDown for each test.  Doing so, causes the application
//to 're-initialize', resulting in repeated calls to the initialize function below
var karma_started = false;
App.initializer({
    name: "run tests",
    initialize: function(container, application) {
        if (!karma_started) {
            karma_started = true;
            __karma__.start();
        }
    }
});

```

--------------------------------

### New Karma Server constructor with parseConfig

Source: https://karma-runner.github.io/6.4/dev/public-api.html

New recommended way to create a Karma server. Uses `karma.config.parseConfig` with `promiseConfig: true` and `throwErrors: true`, then constructs a `Server` with the parsed config. The callback logs the exit code and calls `process.exit`.

```javascript
const karma = require('karma')
const parseConfig = karma.config.parseConfig
const Server = karma.Server

parseConfig(
  null,
  { port: 9876 },
  { promiseConfig: true, throwErrors: true }
).then(
  (karmaConfig) => {
    const server = new Server(karmaConfig, function doneCallback(exitCode) {
      console.log('Karma has exited with ' + exitCode)
      process.exit(exitCode)
    })
  },
  (rejectReason) => { /* respond to the rejection reason error */ }
);

```

--------------------------------

### Generate Karma config file with karma init

Source: https://karma-runner.github.io/6.4/intro/configuration.html

Run `karma init my.conf.js` to interactively generate a configuration file. The command prompts for testing framework, Require.js usage, browser capture, source/test file patterns, exclusions, and file watching. The output shows the generated config file path.

```bash
$ karma init my.conf.js

Which testing framework do you want to use?
Press tab to list possible options. Enter to move to the next question.
> jasmine

Do you want to use Require.js?
This will add Require.js plugin.
Press tab to list possible options. Enter to move to the next question.
> no

Do you want to capture a browser automatically?
Press tab to list possible options. Enter empty string to move to the next question.
> Chrome
> Firefox
>

What is the location of your source and test files?
You can use glob patterns, eg. "js/*.js" or "test/**/*Spec.js".
Press Enter to move to the next question.
> *.js
> test/**/*.js
>

Should any of the files included by the previous patterns be excluded?
You can use glob patterns, eg. "**/*.swp".
Press Enter to move to the next question.
>

Do you want Karma to watch all the files and run the tests on change?
Press tab to list possible options.
> yes

Config file generated at "/Users/vojta/Code/karma/my.conf.js".

```

--------------------------------

### proxyReq example: overwriting HTTP header

Source: https://karma-runner.github.io/6.4/config/configuration-file.html

Use this configuration to modify the proxy request before it is sent. The example sets the 'Referer' header to 'https://www.example.com/'. This function is called when requesting through the proxy.

```javascript
proxyReq: function(proxyReq, req, res, options) {
  proxyReq.setHeader('Referer', 'https://www.example.com/');
}

```

--------------------------------

### Manual requirejs loading with knockout.js

Source: https://karma-runner.github.io/6.4/plus/requirejs.html

Alternative configuration to load requirejs and adapter manually, allowing custom script order.

```javascript
  config.set({
    frameworks: ['jasmine'],

    files: [
      'knockout.js',

      'node_modules/requirejs/require.js',
      'node_modules/karma-requirejs/lib/adapter.js',

      {pattern: 'lib/**/*.js', included: false},
      {pattern: 'src/**/*.js', included: false},
      {pattern: 'test/**/*Spec.js', included: false},

      'test/test-main.js'
    ],

```

--------------------------------

### Set up test command in package.json

Source: https://karma-runner.github.io/6.4/plus/travis.html

Add Karma as a devDependency and define the test script to run Karma with PhantomJS. Travis runs npm test to trigger your tests.

```json
// ...snip...
"devDependencies": {
  "karma": "~0.12"
},
// ...snip...
"scripts": {
   "test": "karma start --single-run --browsers PhantomJS"
}
// ...snip...

```

--------------------------------

### karma.Server constructor

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Constructor for the Karma Server class. It initializes a new server instance with the provided configuration and an optional exit callback.

```APIDOC
## karma.Server(options, [callback=process.exit])

### Description
Creates a new Karma server instance. The constructor accepts a configuration object and an optional callback that is invoked when the server exits.

### Method
constructor

### Parameters
- **options** (object) - Required - Karma configuration object.
- **callback** (function) - Optional - Callback function that receives the exit code.

### Returns
- **Server** - A new Server instance.

### Usage
```
var Server = require('karma').Server
var karmaConfig = {port: 9876}
var server = new Server(karmaConfig, function(exitCode) {
  console.log('Karma has exited with ' + exitCode)
  process.exit(exitCode)
})
```

### New Behavior
```
const karma = require('karma')
const parseConfig = karma.config.parseConfig
const Server = karma.Server

parseConfig(
  null,
  { port: 9876 },
  { promiseConfig: true, throwErrors: true }
).then(
  (karmaConfig) => {
    const server = new Server(karmaConfig, function doneCallback(exitCode) {
      console.log('Karma has exited with ' + exitCode)
      process.exit(exitCode)
    })
  },
  (rejectReason) => { /* respond to the rejection reason error */ }
);
```
```

--------------------------------

### Event: 'browser_start'

Source: https://karma-runner.github.io/6.4/dev/public-api.html

Event emitted when a test run is beginning in a browser.

```APIDOC
## Event: 'browser_start'

### Description
Emitted when a test run is beginning in a browser.

### Arguments
- **browser** (object) - The browser instance.
- **info** (object) - Details about the run.
```

--------------------------------

### Load image assets with glob pattern

Source: https://karma-runner.github.io/6.4/config/files.html

Configure files to serve image assets from a glob pattern. Watched and included are not necessary for images, but served must be true. Images are accessed at http://localhost:[PORT]/base/test/images/[MY IMAGE].jpg.

```javascript
files: [
  {pattern: 'test/images/*.jpg', watched: false, included: false, served: true, nocache: false}
],

```

--------------------------------

### Configure Travis with Node.js

Source: https://karma-runner.github.io/6.4/plus/travis.html

Create a .travis.yml file in your project root with this YAML content to set up Travis CI for Node.js.

```yaml
language: node_js
node_js:
  - "4"

```

--------------------------------

### Add Karma plugins to package.json devDependencies

Source: https://karma-runner.github.io/6.4/config/plugins.html

Add Karma plugins as project dependencies in package.json. The recommended way to install plugins is to add them as devDependencies.

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

```