Chrome Launcher

Launch Google Chrome with ease from node.

• Disables many Chrome services that add noise to automated scenarios
• Opens up the browser's remote-debugging-port on an available port
• Automagically locates a Chrome binary to launch
• Uses a fresh Chrome profile for each launch, and cleans itself up on kill()
• Binds Ctrl-C (by default) to terminate the Chrome process
• Exposes a small set of options for configurability over these details

Installing

yarn add chrome-launcher

# or with npm:
npm install chrome-launcher

API

.launch([opts])

Launch options

{
  // (optional) remote debugging port number to use. If provided port is already busy, launch() will reject
  // Default: an available port is autoselected
  port: number;

  // (optional) Additional flags to pass to Chrome, for example: ['--headless', '--disable-gpu']
  // See all flags here: http://peter.sh/experiments/chromium-command-line-switches/
  // Do note, many flags are set by default: https://github.com/GoogleChrome/lighthouse/blob/master/chrome-launcher/flags.ts
  chromeFlags: Array<string>;

  // (optional) Close the Chrome process on `Ctrl-C`
  // Default: true
  handleSIGINT: boolean;

  // (optional) Explicit path of intended Chrome binary
  // * If this `chromePath` option is defined, it will be used.
  // * Otherwise, the `CHROME_PATH` env variable will be used if set. (`LIGHTHOUSE_CHROMIUM_PATH` is deprecated)
  // * Otherwise, a detected Chrome Canary will be used if found
  // * Otherwise, a detected Chrome (stable) will be used
  chromePath: string;

  // (optional) Chrome profile path to use
  // By default, a fresh Chrome profile will be created
  userDataDir: string;

  // (optional) Starting URL to open the browser with
  // Default: `about:blank`
  startingUrl: string;

  // (optional) Logging level: verbose, info, error, silent
  // Default: 'info'
  logLevel: string;

  // (optional) Enable extension loading
  // Default: false
  enableExtensions: boolean
};

Launched chrome interface

.launch().then(chrome => ...

// The remote debugging port exposed by the launched chrome
chrome.port: number;

// Method kill Chrome (and cleanup the profile folder)
chrome.kill: () => Promise<{}>;

// The process id
chrome.pid: number;

Examples

Launching chrome:

const chromeLauncher = require('chrome-launcher');

chromeLauncher.launch({
  startingUrl: 'https://google.com'
}).then(chrome => {
  console.log(`Chrome debugging port running on ${chrome.port}`);
});

Launching headless chrome:

const chromeLauncher = require('chrome-launcher');

chromeLauncher.launch({
  startingUrl: 'https://google.com',
  chromeFlags: ['--headless', '--disable-gpu']
}).then(chrome => {
  console.log(`Chrome debugging port running on ${chrome.port}`);
});

Continuous Integration

In a CI environment like Travis, Chrome may not be installed. If you want to use chrome-launcher, you can install Chrome using Lighthouse's download-chrome.sh script:

curl -L https://raw.githubusercontent.com/GoogleChrome/lighthouse/v2.1.0/lighthouse-core/scripts/download-chrome.sh | bash

Then in .travis.yml, use it like so:

language: node_js
install:
  - yarn install
before_script:
  - export DISPLAY=:99.0
  - export CHROME_PATH="$(pwd)/chrome-linux/chrome"
  - sh -e /etc/init.d/xvfb start
  - curl -L https://raw.githubusercontent.com/GoogleChrome/lighthouse/v2.1.0/lighthouse-core/scripts/download-chrome.sh | bash