karma.conf.js

const path = require('path');
const alias = require('@rollup/plugin-alias');
const nodeResolve = require('@rollup/plugin-node-resolve');
const commonjs = require('@rollup/plugin-commonjs');
const istanbul = require('rollup-plugin-istanbul');
const babel = require('rollup-plugin-babel');
const minimist = require('minimist');
const c = require('ansi-colors');

const argv = minimist(process.argv.slice(2));
var coverage = String(process.env.COVERAGE) === 'true',
  ci = String(process.env.CI).match(/^(1|true)$/gi),
  pullRequest = !String(process.env.TRAVIS_PULL_REQUEST).match(
    /^(0|false|undefined)$/gi
  ),
  masterBranch = String(process.env.TRAVIS_BRANCH).match(/^master$/gi),
  // Get a Sauce Labs account and remove the `false`
  sauceLabs = false && ci && !pullRequest && masterBranch;

var sauceLabsLaunchers = {
  sl_chrome: {
    base: 'SauceLabs',
    browserName: 'chrome',
    platform: 'Windows 10',
  },
  sl_firefox: {
    base: 'SauceLabs',
    browserName: 'firefox',
    platform: 'Windows 10',
  },
  sl_safari: {
    base: 'SauceLabs',
    browserName: 'safari',
    platform: 'OS X 10.11',
  },
  sl_edge: {
    base: 'SauceLabs',
    browserName: 'MicrosoftEdge',
    platform: 'Windows 10',
  },
  sl_ie_11: {
    base: 'SauceLabs',
    browserName: 'internet explorer',
    version: '11.0',
    platform: 'Windows 7',
  },
};

var localLaunchers = {
  ChromeNoSandboxHeadless: {
    base: 'Chrome',
    flags: [
      '--no-sandbox',
      // See https://chromium.googlesource.com/chromium/src/+/lkgr/headless/README.md
      argv.open ? '' : '--headless',
      '--disable-gpu',
      '--disable-translate',
      '--disable-extensions',
      // Without a remote debugging port, Google Chrome exits immediately.
      '--remote-debugging-port=9333',
      // Removes that crazy long prefix HeadlessChrome 79.0.3945 (Mac OS X 10.15.2)
      '--user-agent=',
    ],
  },
};

module.exports = function (config) {
  config.set({
    browsers: sauceLabs
      ? Object.keys(sauceLabsLaunchers)
      : Object.keys(localLaunchers),

    customLaunchers: sauceLabs ? sauceLabsLaunchers : localLaunchers,

    sauceLabs: {
      build:
        'CI #' +
        process.env.TRAVIS_BUILD_NUMBER +
        ' (' +
        process.env.TRAVIS_BUILD_ID +
        ')',
      tunnelIdentifier:
        process.env.TRAVIS_JOB_NUMBER ||
        'local' + require('./package.json').version,
      connectLocationForSERelay: 'localhost',
      connectPortForSERelay: 4445,
      startConnect: false,
    },

    // browserLogOptions: { terminal: true },
    // browserConsoleLogOptions: { terminal: true },
    browserConsoleLogOptions: {
      level: 'warn', // Filter on warn messages.
      format: '%b %T: %m',
      terminal: true,
    },

    browserNoActivityTimeout: 60 * 60 * 1000,

    // Use only one browser, works better with open source Sauce Labs remote testing
    concurrency: 2,

    captureTimeout: 0,

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

    client: { captureConsole: !!argv.console },

    // test results reporter to use
    // possible values: 'dots', 'progress'
    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
    reporters: ['tap-pretty'].concat(
      coverage ? 'coverage' : [],
      sauceLabs ? 'saucelabs' : []
    ),

    tapReporter: {
      prettify: require('faucet'), // require('tap-spec')
    },

    formatError(msg) {
      msg = msg.replace(/\([^<]+/gm, '');
      msg = msg.replace(/(\bat\s.*)/gms, argv.stack ? c.dim('$1') : '');
      return msg;
    },

    coverageReporter: {
      dir: path.join(__dirname, 'coverage'),
      reporters: [
        { type: 'text' },
        { type: 'html' },
        { type: 'lcovonly', subdir: '.', file: 'lcov.info' },
      ],
    },

    frameworks: ['tap'],

    files: [
      'https://polyfill.io/v3/polyfill.min.js?features=Element.prototype.dataset%2CArray.from',
      {
        pattern: config.grep || 'test/**/*.js',
        watched: false,
      },
    ],

    preprocessors: {
      'test/**/*.js': ['rollup'],
    },

    rollupPreprocessor: {
      output: {
        format: 'iife', // Helps prevent naming collisions.
        name: 'library', // Required for 'iife' format.
        sourcemap: 'inline', // Sensible for testing.
      },
      preserveSymlinks: true,
      plugins: [
        alias({
          entries: {
            tape: 'tape-browser',
            libraryTest: __dirname + 'src/index.js',
          },
        }),
        nodeResolve(),
        commonjs(),
        istanbul({
          include: config.grep
            ? config.grep.replace('/test/', '/src/')
            : 'src/**/*.js',
        }),
        sauceLabs &&
          babel({
            include: ['src/**'],
          }),
      ].filter(Boolean),
      onwarn: (msg) => /eval/.test(msg) && void 0,
    },
  });
};