karma.conf.js

var webpackConfig = require('./webpack.config.js')

module.exports = function(config) {
  config.set({

    // frameworks to use
    // available frameworks: https://npmjs.org/browse/keyword/karma-adapter    
    frameworks: ['jasmine'],

    files: [
      'test/**/*.spec.js'
    ],

    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: { //do not add 'coverage' here, as code already instrumented in babel plugin
      'src/**/*.js': ['webpack'],
      '**/*.spec.js': ['webpack']
    },

    webpack: webpackConfig,

    reporters: ['spec', 'coverage'],

    coverageReporter: {
      dir: './coverage',
      reporters: [
        { type: 'lcov', subdir: '.' },
        { type: 'text-summary' }
      ]
    },

    // enable / disable colors in the output (reporters and logs)
    colors: true,

    // level of logging
    // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
    logLevel: config.LOG_ERROR,

    // start these browsers
    // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
    browsers: [
        'ChromeHeadless','FirefoxHeadless'
    ],
  })
}