grunt-karma.js

/*
 * grunt-karma
 * https://github.com/karma-runner/grunt-karma
 *
 * Copyright (c) 2013 Dave Geddes
 * Licensed under the MIT license.
 */

var runner = require('karma').runner
var Server = require('karma').Server
var path = require('path')
var _ = require('lodash')

function finished (code) {
  return this(code === 0)
}

// Parse out all cli arguments in the form of `--arg=something` or
// `-c=otherthing` and return the array.
function parseArgs (args) {
  return _.filter(args, function (arg) {
    return arg.match(/^--?/)
  })
}

module.exports = function (grunt) {
  grunt.registerMultiTask('karma', 'run karma.', function () {
    var done = this.async()
    var options = this.options({
      background: false,
      client: {}
    })

    // Allow for passing cli arguments to `client.args` using  `--grep=x`
    var args = parseArgs(process.argv.slice(2))
    if (options.client && _.isArray(options.client.args)) {
      args = options.client.args.concat(args)
    }

    // If arguments are provided we pass them to karma
    if (args.length > 0) {
      if (!options.client) {
        options.client = {}
      }
      options.client.args = args
    }

    // Only create client info if data is provided
    if (options.client) {
      // Merge karma default options
      _.defaults(options.client, {
        args: [],
        useIframe: true,
        captureConsole: true
      })
    }

    var opts = _.cloneDeep(options)
    // Merge options onto data, with data taking precedence.
    var data = _.merge(opts, this.data)

    // But override the browsers array.
    if (data.browsers && this.data.browsers) {
      data.browsers = this.data.browsers
    }

    // Merge client.args
    if (this.data.client && _.isArray(this.data.client.args)) {
      data.client.args = this.data.client.args.concat(options.client.args)
    }

    if (data.configFile) {
      data.configFile = path.resolve(data.configFile)
    }

    if (data.files || options.files) {
      data.files = [].concat.apply(options.files || [], this.files.map(function (file) {
        return file.src.map(function (src) {
          var obj = {
            pattern: src
          }
          var opts = ['watched', 'served', 'included']
          opts.forEach(function (opt) {
            if (opt in file) {
              obj[opt] = file[opt]
            }
          })
          return obj
        })
      }))
      data.files = _.flattenDeep(data.files)
    }

    // Allow the use of templates in preprocessors
    if (_.isPlainObject(data.preprocessors)) {
      var preprocessors = {}
      Object.keys(data.preprocessors).forEach(function (key) {
        var value = data.preprocessors[key]
        key = path.resolve(key)
        key = grunt.template.process(key)
        preprocessors[key] = value
      })
      data.preprocessors = preprocessors
    }

    // support `karma run`, useful for grunt watch
    if (this.flags.run) {
      runner.run(data, finished.bind(done))
      return
    }

    // allow karma to be run in the background so it doesn't block grunt
    if (data.background) {
      var backgroundProcess = require('child_process').fork(
          path.join(__dirname, '..', 'lib', 'background.js')
      )

      backgroundProcess.on('close', function (code) {
        var error = code
        if (error) {
          grunt.log.error('background karma process exited with error (code: ' + code + ')')
        }
      })

      process.on('exit', function () {
        backgroundProcess.kill()
      })

      backgroundProcess.send({ config: data })
      done()
    } else {
      var server = new Server(data, finished.bind(done))
      server.start()
    }
  })
}