Public Api

Most of the time, you will be using Karma directly from the command line. You can, however, call Karma programmatically from your node module. Here is the public API.

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

constructor #

• Returns: Server instance.

Usage #

Notice the capital 'S' on require('karma').Server.

Deprecated Behavior #

The following still works, but the way it behaves is deprecated and will be changed in a future major version.

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 */ }
);

server.start() #

Equivalent of karma start.

server.start()

server.refreshFiles() #

Trigger a file list refresh. Returns a promise.

server.refreshFiles()

server.refreshFile(path) #

Trigger a file refresh. Returns a promise.

server.refreshFile('src/js/module-dep.js')

Events #

The server object is an EventEmitter. You can simply listen to events like this:

server.on('browser_register', function (browser) {
  console.log('A new browser was registered')
})

listening #

Arguments:

• port: Port number

Begin accepting connections on the specified port.

browser_register #

Arguments:

• browser: The browser instance

A new browser was opened, but is not ready yet.

browser_error #

Arguments:

• browser: The browser instance
• error: The error that occurred

There was an error in this browser instance.

browser_start #

Arguments:

• browser: The browser instance
• info: Details about the run

A test run is beginning in this browser.

browser_complete #

Arguments:

• browser: The browser instance
• result: Test results

A test run has completed in this browser.

browsers_change #

Arguments:

• browsers: A collection of browser instances

The list of browsers has changed.

browsers_ready #

All browsers are ready for execution

run_start #

Arguments:

• browsers: A collection of browser instances on which tests are executed

A test run starts.

run_complete #

Arguments:

• browsers: A collection of browser instances
• results: A list of results

This event gets triggered whenever all the browsers, which belong to a test run, finish. For example, on a run that has 3 browsers, one would expect 3 browser_complete events before the run_complete one.

karma.runner #

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

• Returns: EventEmitter

The equivalent of karma run.

Usage #

Deprecated Behavior #

The following still works, but the way it behaves is deprecated and will be changed in a future major version.

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

New Behavior #

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 */ }
);

callback argument #

The callback receives the exit code as the first argument.

If there is an error, the error code will be provided as the second parameter to the error callback.

runner Events #

runner.run() returns an EventEmitter which emits a progress event passing the reporter output as a Buffer object.

You may listen for that event to print the reporter output to the console:

runner.run({port: 9876}).on('progress', function(data) {
  process.stdout.write(data)
})

karma.stopper #

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

This function will signal a running server to stop. The equivalent of karma stop.

Usage #

Deprecated Behavior #

The following still works, but the way it behaves is deprecated and will be changed in a future major version.

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

New Behavior #

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 */ }
);

callback argument #

The callback receives the exit code as the first argument.

If there is an error, the error code will be provided as the second parameter to the error callback.

karma.config #

config.parseConfig([configFilePath], [cliOptions], [parseOptions]) #

This function will load given config file and returns a filled config object. This can be useful if you want to integrate karma into another tool and want to load the karma config while honoring the karma defaults.

Usage #

Deprecated Behavior #

The following still works, but the way it behaves is deprecated and will be changed in a future major version.

const cfg = require('karma').config;
const path = require('path');
// Read karma.conf.js, but override port with 1337
const karmaConfig = cfg.parseConfig(
  path.resolve('./karma.conf.js'),
  { port: 1337 }
);

The new behavior in the future will involve throwing exceptions instead of exiting the process and asynchronous config files will be supported through the use of promises.

New Behavior #

const cfg = require('karma').config;
const path = require('path');
// Read karma.conf.js, but override port with 1337
cfg.parseConfig(
  path.resolve('./karma.conf.js'),
  { port: 1337 },
  { promiseConfig: true, throwErrors: true }
).then(
  (karmaConfig) => { /* use the config with the public API */ },
  (rejectReason) => { /* respond to the rejection reason error */ }
);

configFilePath argument #

• Type: String | null | undefined
• Default Value: undefined

A string representing a file system path pointing to the config file whose default export is a function that will be used to set Karma configuration options. This function will be passed an instance of the Config class as its first argument. If this option is not provided, then only the options provided by the cliOptions argument will be set.

• JavaScript must use CommonJS modules.
• ECMAScript modules are not currently supported by Karma when using JavaScript.
  • Other formats, such as TypeScript, may support ECMAScript modules.

cliOptions argument #

• Type: Object | null | undefined
• Default Value: undefined

An object whose values will take priority over options set in the config file. The config object passed to function exported by the config file will already have these options applied. Any changes the config file makes to these options will effectively be ignored in the final configuration.

Supports all the same options as the config file and is applied using the same config.set() method.

The expected source of this argument is parsed command line options, but programatic users may construct this object or leave it out entirely.

parseOptions argument #

• Type: Object | null | undefined
• Default Value: undefined

parseOptions is an object whose properties are configuration options that allow additional control over parsing and opt-in access to new behaviors or features.

These options are only related to parsing configuration files and object and are not related to the configuration of Karma itself.

parseOptions.promiseConfig option #

• Type: Boolean
• Default Value: false

When parseOptions.promiseConfig === true, then parseConfig will return a promise instead of a configuration object.

When this option is true, then the function exported by the config file may return a promise. The resolution of that promise indicates that all asynchronous activity has been completed. Internally, the resolved/fulfilled value is ignored. As with synchronous usage, all changes to the config object must be done with the config.set() method.

If the function exported by the config file does not return a promise, then parsing is completed and an immediately fulfilled promise is returned.

Whether the function exported by the config file returns a promise or not, the promise returned by parseConfig() will resolve with a parsed configuration object, an instance of the Config class, as the value.

In most cases, parseOptions.throwErrors = true should also be set. This disables process exiting and allows errors to result in rejected promises.

parseOptions.throwErrors option #

• Type: Boolean
• Default Value: false

In the past, parseConfig() would call process.exit(exitCode) when it encountered a critical failure. This meant that your own code had no way of responding to failures before the Node.js process exited.

By passing parseOptions.throwErrors = true, parseConfig() will disable process exiting.

For synchronous usage, it will throw an exception instead of exiting the process. Your code can then catch the exception and respond how ever it needs to.

If the asynchronous API (parseOptions.promiseConfig = true) is being used, then parseOptions.throwErrors = true allows the promise to be rejected instead of exiting the process.

karma.constants #

constants.VERSION #

The current version of karma

constants.DEFAULT_PORT #

The default port used for the karma server

constants.DEFAULT_HOSTNAME #

The default hostname used for the karma server

constants.DEFAULT_LISTEN_ADDR #

The default address use for the karma server to listen on

constants.LOG_DISABLE #

The value for disabling logs

constants.LOG_ERROR #

The value for the log error level

constants.LOG_WARN #

The value for the log warn level

constants.LOG_INFO #

The value for the log info level

constants.LOG_DEBUG #

The value for the log debug level

constants.LOG_PRIORITIES #

An array of log levels in descending order, i.e. LOG_DISABLE, LOG_ERROR, LOG_WARN, LOG_INFO, and LOG_DEBUG

constants.COLOR_PATTERN #

The default color pattern for log output

constants.NO_COLOR_PATTERN #

The default pattern for log output without color

constants.CONSOLE_APPENDER #

The default console appender

constants.EXIT_CODE #

The exit code