puppeteer/lib/Launcher.js

/**
 * Copyright 2017 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
const os = require('os');
const path = require('path');
const http = require('http');
const https = require('https');
const URL = require('url');
const removeFolder = require('rimraf');
const childProcess = require('child_process');
const BrowserFetcher = require('./BrowserFetcher');
const {Connection} = require('./Connection');
const {Browser} = require('./Browser');
const readline = require('readline');
const fs = require('fs');
const {helper, assert, debugError} = require('./helper');
const debugLauncher = require('debug')(`puppeteer:launcher`);
const {TimeoutError} = require('./Errors');
const WebSocketTransport = require('./WebSocketTransport');
const PipeTransport = require('./PipeTransport');

const mkdtempAsync = helper.promisify(fs.mkdtemp);
const removeFolderAsync = helper.promisify(removeFolder);
const writeFileAsync = helper.promisify(fs.writeFile);

class BrowserRunner {

  /**
   * @param {string} executablePath
   * @param {!Array<string>} processArguments
   * @param {string=} tempDirectory
   */
  constructor(executablePath, processArguments, tempDirectory) {
    this._executablePath = executablePath;
    this._processArguments = processArguments;
    this._tempDirectory = tempDirectory;
    this.proc = null;
    this.connection = null;
    this._closed = true;
    this._listeners = [];
  }

  /**
   * @param {!(Launcher.LaunchOptions)=} options
   */
  start(options = {}) {
    const {
      handleSIGINT,
      handleSIGTERM,
      handleSIGHUP,
      dumpio,
      env,
      pipe
    } = options;
    /** @type {!Array<"ignore"|"pipe">} */
    let stdio = ['pipe', 'pipe', 'pipe'];
    if (pipe) {
      if (dumpio)
        stdio = ['ignore', 'pipe', 'pipe', 'pipe', 'pipe'];
      else
        stdio = ['ignore', 'ignore', 'ignore', 'pipe', 'pipe'];
    }
    assert(!this.proc, 'This process has previously been started.');
    debugLauncher(`Calling ${this._executablePath} ${this._processArguments.join(' ')}`);
    this.proc = childProcess.spawn(
        this._executablePath,
        this._processArguments,
        {
          // On non-windows platforms, `detached: true` makes child process a leader of a new
          // process group, making it possible to kill child process tree with `.kill(-pid)` command.
          // @see https://nodejs.org/api/child_process.html#child_process_options_detached
          detached: process.platform !== 'win32',
          env,
          stdio
        }
    );
    if (dumpio) {
      this.proc.stderr.pipe(process.stderr);
      this.proc.stdout.pipe(process.stdout);
    }
    this._closed = false;
    this._processClosing = new Promise((fulfill, reject) => {
      this.proc.once('exit', () => {
        this._closed = true;
        // Cleanup as processes exit.
        if (this._tempDirectory) {
          removeFolderAsync(this._tempDirectory)
              .then(() => fulfill())
              .catch(err => console.error(err));
        } else {
          fulfill();
        }
      });
    });
    this._listeners = [ helper.addEventListener(process, 'exit', this.kill.bind(this)) ];
    if (handleSIGINT)
      this._listeners.push(helper.addEventListener(process, 'SIGINT', () => { this.kill(); process.exit(130); }));
    if (handleSIGTERM)
      this._listeners.push(helper.addEventListener(process, 'SIGTERM', this.close.bind(this)));
    if (handleSIGHUP)
      this._listeners.push(helper.addEventListener(process, 'SIGHUP', this.close.bind(this)));
  }

  /**
   * @return {Promise}
   */
  close() {
    if (this._closed)
      return Promise.resolve();
    helper.removeEventListeners(this._listeners);
    if (this._tempDirectory) {
      this.kill();
    } else if (this.connection) {
      // Attempt to close the browser gracefully
      this.connection.send('Browser.close').catch(error => {
        debugError(error);
        this.kill();
      });
    }
    return this._processClosing;
  }

  // This function has to be sync to be used as 'exit' event handler.
  kill() {
    helper.removeEventListeners(this._listeners);
    if (this.proc && this.proc.pid && !this.proc.killed && !this._closed) {
      try {
        if (process.platform === 'win32')
          childProcess.execSync(`taskkill /pid ${this.proc.pid} /T /F`);
        else
          process.kill(-this.proc.pid, 'SIGKILL');
      } catch (error) {
        // the process might have already stopped
      }
    }
    // Attempt to remove temporary profile directory to avoid littering.
    try {
      removeFolder.sync(this._tempDirectory);
    } catch (error) { }
  }

  /**
   * @param {!({usePipe?: boolean, timeout: number, slowMo: number, preferredRevision: string})} options
   *
   * @return {!Promise<!Connection>}
   */
  async setupConnection(options) {
    const {
      usePipe,
      timeout,
      slowMo,
      preferredRevision
    } = options;
    if (!usePipe) {
      const browserWSEndpoint = await waitForWSEndpoint(this.proc, timeout, preferredRevision);
      const transport = await WebSocketTransport.create(browserWSEndpoint);
      this.connection = new Connection(browserWSEndpoint, transport, slowMo);
    } else {
      const transport = new PipeTransport(/** @type {!NodeJS.WritableStream} */(this.proc.stdio[3]), /** @type {!NodeJS.ReadableStream} */ (this.proc.stdio[4]));
      this.connection = new Connection('', transport, slowMo);
    }
    return this.connection;
  }
}

/**
 * @implements {!Puppeteer.ProductLauncher}
 */
class ChromeLauncher {
  /**
   * @param {string} projectRoot
   * @param {string} preferredRevision
   * @param {boolean} isPuppeteerCore
   */
  constructor(projectRoot, preferredRevision, isPuppeteerCore) {
    this._projectRoot = projectRoot;
    this._preferredRevision = preferredRevision;
    this._isPuppeteerCore = isPuppeteerCore;
  }

  /**
   * @param {!(Launcher.LaunchOptions & Launcher.ChromeArgOptions & Launcher.BrowserOptions)=} options
   * @return {!Promise<!Browser>}
   */
  async launch(options = {}) {
    const {
      ignoreDefaultArgs = false,
      args = [],
      dumpio = false,
      executablePath = null,
      pipe = false,
      env = process.env,
      handleSIGINT = true,
      handleSIGTERM = true,
      handleSIGHUP = true,
      ignoreHTTPSErrors = false,
      defaultViewport = {width: 800, height: 600},
      slowMo = 0,
      timeout = 30000
    } = options;

    const profilePath = path.join(os.tmpdir(), 'puppeteer_dev_chrome_profile-');
    const chromeArguments = [];
    if (!ignoreDefaultArgs)
      chromeArguments.push(...this.defaultArgs(options));
    else if (Array.isArray(ignoreDefaultArgs))
      chromeArguments.push(...this.defaultArgs(options).filter(arg => !ignoreDefaultArgs.includes(arg)));
    else
      chromeArguments.push(...args);

    let temporaryUserDataDir = null;

    if (!chromeArguments.some(argument => argument.startsWith('--remote-debugging-')))
      chromeArguments.push(pipe ? '--remote-debugging-pipe' : '--remote-debugging-port=0');
    if (!chromeArguments.some(arg => arg.startsWith('--user-data-dir'))) {
      temporaryUserDataDir = await mkdtempAsync(profilePath);
      chromeArguments.push(`--user-data-dir=${temporaryUserDataDir}`);
    }

    let chromeExecutable = executablePath;
    if (!executablePath) {
      const {missingText, executablePath} = resolveExecutablePath(this);
      if (missingText)
        throw new Error(missingText);
      chromeExecutable = executablePath;
    }

    const usePipe = chromeArguments.includes('--remote-debugging-pipe');
    const runner = new BrowserRunner(chromeExecutable, chromeArguments, temporaryUserDataDir);
    runner.start({handleSIGHUP, handleSIGTERM, handleSIGINT, dumpio, env, pipe: usePipe});

    try {
      const connection = await runner.setupConnection({usePipe, timeout, slowMo, preferredRevision: this._preferredRevision});
      const browser = await Browser.create(connection, [], ignoreHTTPSErrors, defaultViewport, runner.proc, runner.close.bind(runner));
      await browser.waitForTarget(t => t.type() === 'page');
      return browser;
    } catch (error) {
      runner.kill();
      throw error;
    }
  }

  /**
   * @param {!Launcher.ChromeArgOptions=} options
   * @return {!Array<string>}
   */
  defaultArgs(options = {}) {
    const chromeArguments = [
      '--disable-background-networking',
      '--enable-features=NetworkService,NetworkServiceInProcess',
      '--disable-background-timer-throttling',
      '--disable-backgrounding-occluded-windows',
      '--disable-breakpad',
      '--disable-client-side-phishing-detection',
      '--disable-component-extensions-with-background-pages',
      '--disable-default-apps',
      '--disable-dev-shm-usage',
      '--disable-extensions',
      '--disable-features=TranslateUI',
      '--disable-hang-monitor',
      '--disable-ipc-flooding-protection',
      '--disable-popup-blocking',
      '--disable-prompt-on-repost',
      '--disable-renderer-backgrounding',
      '--disable-sync',
      '--force-color-profile=srgb',
      '--metrics-recording-only',
      '--no-first-run',
      '--enable-automation',
      '--password-store=basic',
      '--use-mock-keychain',
    ];
    const {
      devtools = false,
      headless = !devtools,
      args = [],
      userDataDir = null
    } = options;
    if (userDataDir)
      chromeArguments.push(`--user-data-dir=${userDataDir}`);
    if (devtools)
      chromeArguments.push('--auto-open-devtools-for-tabs');
    if (headless) {
      chromeArguments.push(
          '--headless',
          '--hide-scrollbars',
          '--mute-audio'
      );
    }
    if (args.every(arg => arg.startsWith('-')))
      chromeArguments.push('about:blank');
    chromeArguments.push(...args);
    return chromeArguments;
  }

  /**
   * @return {string}
   */
  executablePath() {
    return resolveExecutablePath(this).executablePath;
  }

  /**
  * @return {string}
  */
  get product() {
    return 'chrome';
  }

  /**
   * @param {!(Launcher.BrowserOptions & {browserWSEndpoint?: string, browserURL?: string, transport?: !Puppeteer.ConnectionTransport})} options
   * @return {!Promise<!Browser>}
   */
  async connect(options) {
    const {
      browserWSEndpoint,
      browserURL,
      ignoreHTTPSErrors = false,
      defaultViewport = {width: 800, height: 600},
      transport,
      slowMo = 0,
    } = options;

    assert(Number(!!browserWSEndpoint) + Number(!!browserURL) + Number(!!transport) === 1, 'Exactly one of browserWSEndpoint, browserURL or transport must be passed to puppeteer.connect');

    let connection = null;
    if (transport) {
      connection = new Connection('', transport, slowMo);
    } else if (browserWSEndpoint) {
      const connectionTransport = await WebSocketTransport.create(browserWSEndpoint);
      connection = new Connection(browserWSEndpoint, connectionTransport, slowMo);
    } else if (browserURL) {
      const connectionURL = await getWSEndpoint(browserURL);
      const connectionTransport = await WebSocketTransport.create(connectionURL);
      connection = new Connection(connectionURL, connectionTransport, slowMo);
    }

    const {browserContextIds} = await connection.send('Target.getBrowserContexts');
    return Browser.create(connection, browserContextIds, ignoreHTTPSErrors, defaultViewport, null, () => connection.send('Browser.close').catch(debugError));
  }

}

/**
 * @implements {!Puppeteer.ProductLauncher}
 */
class FirefoxLauncher {
  /**
   * @param {string} projectRoot
   * @param {string} preferredRevision
   * @param {boolean} isPuppeteerCore
   */
  constructor(projectRoot, preferredRevision, isPuppeteerCore) {
    this._projectRoot = projectRoot;
    this._preferredRevision = preferredRevision;
    this._isPuppeteerCore = isPuppeteerCore;
  }

  /**
   * @param {!(Launcher.LaunchOptions & Launcher.ChromeArgOptions & Launcher.BrowserOptions & {extraPrefsFirefox?: !object})=} options
   * @return {!Promise<!Browser>}
   */
  async launch(options = {}) {
    const {
      ignoreDefaultArgs = false,
      args = [],
      dumpio = false,
      executablePath = null,
      pipe = false,
      env = process.env,
      handleSIGINT = true,
      handleSIGTERM = true,
      handleSIGHUP = true,
      ignoreHTTPSErrors = false,
      defaultViewport = {width: 800, height: 600},
      slowMo = 0,
      timeout = 30000,
      extraPrefsFirefox = {}
    } = options;

    const firefoxArguments = [];
    if (!ignoreDefaultArgs)
      firefoxArguments.push(...this.defaultArgs(options));
    else if (Array.isArray(ignoreDefaultArgs))
      firefoxArguments.push(...this.defaultArgs(options).filter(arg => !ignoreDefaultArgs.includes(arg)));
    else
      firefoxArguments.push(...args);

    let temporaryUserDataDir = null;

    if (!firefoxArguments.includes('-profile') && !firefoxArguments.includes('--profile')) {
      temporaryUserDataDir = await this._createProfile(extraPrefsFirefox);
      firefoxArguments.push('--profile');
      firefoxArguments.push(temporaryUserDataDir);
    }

    let executable = executablePath;
    if (!executablePath) {
      const {missingText, executablePath} = resolveExecutablePath(this);
      if (missingText)
        throw new Error(missingText);
      executable = executablePath;
    }

    const runner = new BrowserRunner(executable, firefoxArguments, temporaryUserDataDir);
    runner.start({handleSIGHUP, handleSIGTERM, handleSIGINT, dumpio, env, pipe});

    try {
      const connection = await runner.setupConnection({usePipe: pipe, timeout, slowMo, preferredRevision: this._preferredRevision});
      const browser = await Browser.create(connection, [], ignoreHTTPSErrors, defaultViewport, runner.proc, runner.close.bind(runner));
      await browser.waitForTarget(t => t.type() === 'page');
      return browser;
    } catch (error) {
      runner.kill();
      throw error;
    }
  }

  /**
   * @param {!(Launcher.BrowserOptions & {browserWSEndpoint?: string, browserURL?: string, transport?: !Puppeteer.ConnectionTransport})} options
   * @return {!Promise<!Browser>}
   */
  async connect(options) {
    const {
      browserWSEndpoint,
      browserURL,
      ignoreHTTPSErrors = false,
      defaultViewport = {width: 800, height: 600},
      transport,
      slowMo = 0,
    } = options;

    assert(Number(!!browserWSEndpoint) + Number(!!browserURL) + Number(!!transport) === 1, 'Exactly one of browserWSEndpoint, browserURL or transport must be passed to puppeteer.connect');

    let connection = null;
    if (transport) {
      connection = new Connection('', transport, slowMo);
    } else if (browserWSEndpoint) {
      const connectionTransport = await WebSocketTransport.create(browserWSEndpoint);
      connection = new Connection(browserWSEndpoint, connectionTransport, slowMo);
    } else if (browserURL) {
      const connectionURL = await getWSEndpoint(browserURL);
      const connectionTransport = await WebSocketTransport.create(connectionURL);
      connection = new Connection(connectionURL, connectionTransport, slowMo);
    }

    const {browserContextIds} = await connection.send('Target.getBrowserContexts');
    return Browser.create(connection, browserContextIds, ignoreHTTPSErrors, defaultViewport, null, () => connection.send('Browser.close').catch(debugError));
  }

  /**
   * @return {string}
   */
  executablePath() {
    const executablePath = process.env.PUPPETEER_EXECUTABLE_PATH || process.env.npm_config_puppeteer_executable_path || process.env.npm_package_config_puppeteer_executable_path;
    // TODO get resolveExecutablePath working for Firefox
    if (!executablePath)
      throw new Error('Please set PUPPETEER_EXECUTABLE_PATH to a Firefox binary.');
    return executablePath;
  }

  /**
   * @return {string}
   */
  get product() {
    return 'firefox';
  }

  /**
   * @param {!Launcher.ChromeArgOptions=} options
   * @return {!Array<string>}
   */
  defaultArgs(options = {}) {
    const firefoxArguments = [
      '--remote-debugging-port=0',
      '--no-remote',
      '--foreground',
    ];
    const {
      devtools = false,
      headless = !devtools,
      args = [],
      userDataDir = null
    } = options;
    if (userDataDir) {
      firefoxArguments.push('--profile');
      firefoxArguments.push(userDataDir);
    }
    if (headless)
      firefoxArguments.push('--headless');
    if (devtools)
      firefoxArguments.push('--devtools');
    if (args.every(arg => arg.startsWith('-')))
      firefoxArguments.push('about:blank');
    firefoxArguments.push(...args);
    return firefoxArguments;
  }

  /**
   * @param {!Object=} extraPrefs
   * @return {!Promise<string>}
   */
  async _createProfile(extraPrefs) {
    const profilePath = await mkdtempAsync(path.join(os.tmpdir(), 'puppeteer_dev_firefox_profile-'));
    const prefsJS = [];
    const userJS = [];
    const server = 'dummy.test';
    const defaultPreferences = {
      // Make sure Shield doesn't hit the network.
      'app.normandy.api_url': '',
      // Disable Firefox old build background check
      'app.update.checkInstallTime': false,
      // Disable automatically upgrading Firefox
      'app.update.disabledForTesting': true,

      // Increase the APZ content response timeout to 1 minute
      'apz.content_response_timeout': 60000,

      // Prevent various error message on the console
      // jest-puppeteer asserts that no error message is emitted by the console
      'browser.contentblocking.features.standard': '-tp,tpPrivate,cookieBehavior0,-cm,-fp',


      // Enable the dump function: which sends messages to the system
      // console
      // https://bugzilla.mozilla.org/show_bug.cgi?id=1543115
      'browser.dom.window.dump.enabled': true,
      // Disable topstories
      'browser.newtabpage.activity-stream.feeds.section.topstories': false,
      // Always display a blank page
      'browser.newtabpage.enabled': false,
      // Background thumbnails in particular cause grief: and disabling
      // thumbnails in general cannot hurt
      'browser.pagethumbnails.capturing_disabled': true,

      // Disable safebrowsing components.
      'browser.safebrowsing.blockedURIs.enabled': false,
      'browser.safebrowsing.downloads.enabled': false,
      'browser.safebrowsing.malware.enabled': false,
      'browser.safebrowsing.passwords.enabled': false,
      'browser.safebrowsing.phishing.enabled': false,

      // Disable updates to search engines.
      'browser.search.update': false,
      // Do not restore the last open set of tabs if the browser has crashed
      'browser.sessionstore.resume_from_crash': false,
      // Skip check for default browser on startup
      'browser.shell.checkDefaultBrowser': false,

      // Disable newtabpage
      'browser.startup.homepage': 'about:blank',
      // Do not redirect user when a milstone upgrade of Firefox is detected
      'browser.startup.homepage_override.mstone': 'ignore',
      // Start with a blank page about:blank
      'browser.startup.page': 0,

      // Do not allow background tabs to be zombified on Android: otherwise for
      // tests that open additional tabs: the test harness tab itself might get
      // unloaded
      'browser.tabs.disableBackgroundZombification': false,
      // Do not warn when closing all other open tabs
      'browser.tabs.warnOnCloseOtherTabs': false,
      // Do not warn when multiple tabs will be opened
      'browser.tabs.warnOnOpen': false,

      // Disable the UI tour.
      'browser.uitour.enabled': false,
      // Turn off search suggestions in the location bar so as not to trigger
      // network connections.
      'browser.urlbar.suggest.searches': false,
      // Disable first run splash page on Windows 10
      'browser.usedOnWindows10.introURL': '',
      // Do not warn on quitting Firefox
      'browser.warnOnQuit': false,

      // Do not show datareporting policy notifications which can
      // interfere with tests
      'datareporting.healthreport.about.reportUrl': `http://${server}/dummy/abouthealthreport/`,
      'datareporting.healthreport.documentServerURI': `http://${server}/dummy/healthreport/`,
      'datareporting.healthreport.logging.consoleEnabled': false,
      'datareporting.healthreport.service.enabled': false,
      'datareporting.healthreport.service.firstRun': false,
      'datareporting.healthreport.uploadEnabled': false,
      'datareporting.policy.dataSubmissionEnabled': false,
      'datareporting.policy.dataSubmissionPolicyAccepted': false,
      'datareporting.policy.dataSubmissionPolicyBypassNotification': true,

      // DevTools JSONViewer sometimes fails to load dependencies with its require.js.
      // This doesn't affect Puppeteer but spams console (Bug 1424372)
      'devtools.jsonview.enabled': false,

      // Disable popup-blocker
      'dom.disable_open_during_load': false,

      // Enable the support for File object creation in the content process
      // Required for |Page.setFileInputFiles| protocol method.
      'dom.file.createInChild': true,

      // Disable the ProcessHangMonitor
      'dom.ipc.reportProcessHangs': false,

      // Disable slow script dialogues
      'dom.max_chrome_script_run_time': 0,
      'dom.max_script_run_time': 0,

      // Only load extensions from the application and user profile
      // AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
      'extensions.autoDisableScopes': 0,
      'extensions.enabledScopes': 5,

      // Disable metadata caching for installed add-ons by default
      'extensions.getAddons.cache.enabled': false,

      // Disable installing any distribution extensions or add-ons.
      'extensions.installDistroAddons': false,

      // Disabled screenshots extension
      'extensions.screenshots.disabled': true,

      // Turn off extension updates so they do not bother tests
      'extensions.update.enabled': false,

      // Turn off extension updates so they do not bother tests
      'extensions.update.notifyUser': false,

      // Make sure opening about:addons will not hit the network
      'extensions.webservice.discoverURL': `http://${server}/dummy/discoveryURL`,

      // Allow the application to have focus even it runs in the background
      'focusmanager.testmode': true,
      // Disable useragent updates
      'general.useragent.updates.enabled': false,
      // Always use network provider for geolocation tests so we bypass the
      // macOS dialog raised by the corelocation provider
      'geo.provider.testing': true,
      // Do not scan Wifi
      'geo.wifi.scan': false,
      // No hang monitor
      'hangmonitor.timeout': 0,
      // Show chrome errors and warnings in the error console
      'javascript.options.showInConsole': true,

      // Disable download and usage of OpenH264: and Widevine plugins
      'media.gmp-manager.updateEnabled': false,
      // Prevent various error message on the console
      // jest-puppeteer asserts that no error message is emitted by the console
      'network.cookie.cookieBehavior': 0,

      // Do not prompt for temporary redirects
      'network.http.prompt-temp-redirect': false,

      // Disable speculative connections so they are not reported as leaking
      // when they are hanging around
      'network.http.speculative-parallel-limit': 0,

      // Do not automatically switch between offline and online
      'network.manage-offline-status': false,

      // Make sure SNTP requests do not hit the network
      'network.sntp.pools': server,

      // Disable Flash.
      'plugin.state.flash': 0,

      'privacy.trackingprotection.enabled': false,

      // Enable Remote Agent
      // https://bugzilla.mozilla.org/show_bug.cgi?id=1544393
      'remote.enabled': true,

      // Don't do network connections for mitm priming
      'security.certerrors.mitm.priming.enabled': false,
      // Local documents have access to all other local documents,
      // including directory listings
      'security.fileuri.strict_origin_policy': false,
      // Do not wait for the notification button security delay
      'security.notification_enable_delay': 0,

      // Ensure blocklist updates do not hit the network
      'services.settings.server': `http://${server}/dummy/blocklist/`,

      // Do not automatically fill sign-in forms with known usernames and
      // passwords
      'signon.autofillForms': false,
      // Disable password capture, so that tests that include forms are not
      // influenced by the presence of the persistent doorhanger notification
      'signon.rememberSignons': false,

      // Disable first-run welcome page
      'startup.homepage_welcome_url': 'about:blank',

      // Disable first-run welcome page
      'startup.homepage_welcome_url.additional': '',

      // Disable browser animations (tabs, fullscreen, sliding alerts)
      'toolkit.cosmeticAnimations.enabled': false,

      // We want to collect telemetry, but we don't want to send in the results
      'toolkit.telemetry.server': `https://${server}/dummy/telemetry/`,
      // Prevent starting into safe mode after application crashes
      'toolkit.startup.max_resumed_crashes': -1,

    };

    Object.assign(defaultPreferences, extraPrefs);
    for (const [key, value] of Object.entries(defaultPreferences))
      userJS.push(`user_pref(${JSON.stringify(key)}, ${JSON.stringify(value)});`);
    await writeFileAsync(path.join(profilePath, 'user.js'), userJS.join('\n'));
    await writeFileAsync(path.join(profilePath, 'prefs.js'), prefsJS.join('\n'));
    return profilePath;
  }
}


/**
 * @param {!Puppeteer.ChildProcess} browserProcess
 * @param {number} timeout
 * @param {string} preferredRevision
 * @return {!Promise<string>}
 */
function waitForWSEndpoint(browserProcess, timeout, preferredRevision) {
  return new Promise((resolve, reject) => {
    const rl = readline.createInterface({ input: browserProcess.stderr });
    let stderr = '';
    const listeners = [
      helper.addEventListener(rl, 'line', onLine),
      helper.addEventListener(rl, 'close', () => onClose()),
      helper.addEventListener(browserProcess, 'exit', () => onClose()),
      helper.addEventListener(browserProcess, 'error', error => onClose(error))
    ];
    const timeoutId = timeout ? setTimeout(onTimeout, timeout) : 0;

    /**
     * @param {!Error=} error
     */
    function onClose(error) {
      cleanup();
      reject(new Error([
        'Failed to launch the browser process!' + (error ? ' ' + error.message : ''),
        stderr,
        '',
        'TROUBLESHOOTING: https://github.com/puppeteer/puppeteer/blob/master/docs/troubleshooting.md',
        '',
      ].join('\n')));
    }

    function onTimeout() {
      cleanup();
      reject(new TimeoutError(`Timed out after ${timeout} ms while trying to connect to the browser! Only Chrome at revision r${preferredRevision} is guaranteed to work.`));
    }

    /**
     * @param {string} line
     */
    function onLine(line) {
      stderr += line + '\n';
      const match = line.match(/^DevTools listening on (ws:\/\/.*)$/);
      if (!match)
        return;
      cleanup();
      resolve(match[1]);
    }

    function cleanup() {
      if (timeoutId)
        clearTimeout(timeoutId);
      helper.removeEventListeners(listeners);
    }
  });
}

/**
 * @param {string} browserURL
 * @return {!Promise<string>}
 */
function getWSEndpoint(browserURL) {
  let resolve, reject;
  const promise = new Promise((res, rej) => { resolve = res; reject = rej; });

  const endpointURL = URL.resolve(browserURL, '/json/version');
  const protocol = endpointURL.startsWith('https') ? https : http;
  const requestOptions = Object.assign(URL.parse(endpointURL), { method: 'GET' });
  const request = protocol.request(requestOptions, res => {
    let data = '';
    if (res.statusCode !== 200) {
      // Consume response data to free up memory.
      res.resume();
      reject(new Error('HTTP ' + res.statusCode));
      return;
    }
    res.setEncoding('utf8');
    res.on('data', chunk => data += chunk);
    res.on('end', () => resolve(JSON.parse(data).webSocketDebuggerUrl));
  });

  request.on('error', reject);
  request.end();

  return promise.catch(e => {
    e.message = `Failed to fetch browser webSocket url from ${endpointURL}: ` + e.message;
    throw e;
  });
}

/**
 * @param {ChromeLauncher|FirefoxLauncher} launcher
 *
 * @return {{executablePath: string, missingText: ?string}}
 */
function resolveExecutablePath(launcher) {
  // puppeteer-core doesn't take into account PUPPETEER_* env variables.
  if (!launcher._isPuppeteerCore) {
    const executablePath = process.env.PUPPETEER_EXECUTABLE_PATH || process.env.npm_config_puppeteer_executable_path || process.env.npm_package_config_puppeteer_executable_path;
    if (executablePath) {
      const missingText = !fs.existsSync(executablePath) ? 'Tried to use PUPPETEER_EXECUTABLE_PATH env variable to launch browser but did not find any executable at: ' + executablePath : null;
      return { executablePath, missingText };
    }
  }
  const browserFetcher = new BrowserFetcher(launcher._projectRoot);
  if (!launcher._isPuppeteerCore) {
    const revision = process.env['PUPPETEER_CHROMIUM_REVISION'];
    if (revision) {
      const revisionInfo = browserFetcher.revisionInfo(revision);
      const missingText = !revisionInfo.local ? 'Tried to use PUPPETEER_CHROMIUM_REVISION env variable to launch browser but did not find executable at: ' + revisionInfo.executablePath : null;
      return {executablePath: revisionInfo.executablePath, missingText};
    }
  }
  const revisionInfo = browserFetcher.revisionInfo(launcher._preferredRevision);
  const missingText = !revisionInfo.local ? `Browser is not downloaded. Run "npm install" or "yarn install"` : null;
  return {executablePath: revisionInfo.executablePath, missingText};
}

/**
 * @param {string} projectRoot
 * @param {string} preferredRevision
 * @param {boolean} isPuppeteerCore
 * @param {string=} product
 * @return {!Puppeteer.ProductLauncher}
 */
function Launcher(projectRoot, preferredRevision, isPuppeteerCore, product) {
  // puppeteer-core doesn't take into account PUPPETEER_* env variables.
  if (!product && !isPuppeteerCore)
    product = process.env.PUPPETEER_PRODUCT || process.env.npm_config_puppeteer_product || process.env.npm_package_config_puppeteer_product;
  switch (product) {
    case 'firefox':
      return new FirefoxLauncher(projectRoot, preferredRevision, isPuppeteerCore);
    case 'chrome':
    default:
      return new ChromeLauncher(projectRoot, preferredRevision, isPuppeteerCore);
  }
}


/**
 * @typedef {Object} Launcher.ChromeArgOptions
 * @property {boolean=} headless
 * @property {Array<string>=} args
 * @property {string=} userDataDir
 * @property {boolean=} devtools
 */

/**
 * @typedef {Object} Launcher.LaunchOptions
 * @property {string=} executablePath
 * @property {boolean|Array<string>=} ignoreDefaultArgs
 * @property {boolean=} handleSIGINT
 * @property {boolean=} handleSIGTERM
 * @property {boolean=} handleSIGHUP
 * @property {number=} timeout
 * @property {boolean=} dumpio
 * @property {!Object<string, string | undefined>=} env
 * @property {boolean=} pipe
 */

/**
 * @typedef {Object} Launcher.BrowserOptions
 * @property {boolean=} ignoreHTTPSErrors
 * @property {(?Puppeteer.Viewport)=} defaultViewport
 * @property {number=} slowMo
 */


module.exports = Launcher;