karma.conf.js

const isparta = require('isparta');
const istanbul = require('browserify-istanbul');

process.env.CHROME_BIN = require('puppeteer').executablePath();

// Karma configuration
module.exports = function(config) {
  config.set({

    // base path that will be used to resolve all patterns (eg. files, exclude)
    basePath: '',

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

    // list of files / patterns to load in the browser
    files: [
      'src/**/*.js',
      'tests/**/*.spec.js'
    ],

    // list of files to exclude
    exclude: [],

    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: {
      'src/**/*.js': ['browserify'],
      'tests/**/*.spec.js': ['browserify']
    },

    // test results reporter to use
    // possible values: 'dots', 'progress'
    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
    reporters: ['spec', 'coverage'],

    // web server port
    port: 9876,

    // 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_DEBUG,

    // enable / disable watching file and executing tests whenever any file changes
    autoWatch: true,

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

    // No sandbox option for TravisCI: https://docs.travis-ci.com/user/chrome#Sandboxing
    customLaunchers: {
      ChromeHeadlessNoSandbox: {
        base: 'ChromeHeadless',
        flags: ['--no-sandbox']
      }
    },

    // Continuous Integration mode
    // if true, Karma captures browsers, runs the tests and exits
    singleRun: false,

    // Concurrency level
    // how many browser should be started simultaneous
    concurrency: Infinity,

    // browserify config
    browserify: {
      debug: true,
      transform: [
        'babelify',
        istanbul({
          instrumenter: isparta,
          ignore: ['**/node_modules/**', '**/tests/**']
        })
      ]
    },

    // coverage reporter config
    coverageReporter: {
      type: 'lcov'
    }
  });
};