What is chrome-launcher?
The chrome-launcher npm package is a tool that allows developers to automate the launching of Google Chrome with specific configurations. It is often used for running automated tests, scraping websites, and automating interactions with web pages.
What are chrome-launcher's main functionalities?
Launching Chrome
This feature allows you to launch a new instance of Chrome. The code sample demonstrates how to launch Chrome with a starting URL.
const chromeLauncher = require('chrome-launcher');
async function launchChrome() {
const chrome = await chromeLauncher.launch({startingUrl: 'https://example.com'});
console.log(`Chrome debugging port running on ${chrome.port}`);
}
launchChrome();
Custom Chrome Flags
This feature enables the use of custom flags when launching Chrome. The code sample shows how to launch Chrome in headless mode with GPU disabled.
const chromeLauncher = require('chrome-launcher');
async function launchChromeWithFlags() {
const chrome = await chromeLauncher.launch({
chromeFlags: ['--headless', '--disable-gpu']
});
console.log(`Chrome debugging port running on ${chrome.port}`);
}
launchChromeWithFlags();
Killing Chrome Instances
This feature allows you to programmatically kill the launched Chrome instance. The code sample illustrates launching Chrome and then killing it after some operations.
const chromeLauncher = require('chrome-launcher');
async function launchAndKillChrome() {
const chrome = await chromeLauncher.launch({startingUrl: 'https://example.com'});
console.log(`Chrome debugging port running on ${chrome.port}`);
// Some time later...
await chrome.kill();
}
launchAndKillChrome();
Other packages similar to chrome-launcher
puppeteer
Puppeteer is a Node library which provides a high-level API to control Chrome or Chromium over the DevTools Protocol. It is similar to chrome-launcher but offers more comprehensive features for interacting with the browser, such as generating screenshots, PDFs, and automating form submissions.
selenium-webdriver
Selenium WebDriver is a browser automation framework that works with multiple browsers, including Chrome. It is more complex and feature-rich compared to chrome-launcher, suitable for full-scale browser automation and testing.
nightmare
Nightmare is a high-level browser automation library. It is built on top of Electron, which is a framework for creating native applications with web technologies. Nightmare is designed for automating tasks in a simplified manner compared to chrome-launcher, with an emphasis on ease of use and simplicity.
Chrome Launcher
![NPM chrome-launcher package](https://img.shields.io/npm/v/chrome-launcher.svg)
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
Once launched, interacting with the browser must be done over the devtools protocol, typically via chrome-remote-interface. For many cases Puppeteer is recommended, though it has its own chrome launching mechanism.
Installing
yarn add chrome-launcher
npm install chrome-launcher
API
.launch([opts])
Launch options
{
port: number;
portStrictMode: boolean;
chromeFlags: Array<string>;
prefs: {[key: string]: Object};
handleSIGINT: boolean;
chromePath: string;
userDataDir: string | boolean;
startingUrl: string;
logLevel: 'verbose'|'info'|'error'|'silent';
ignoreDefaultFlags: boolean;
connectionPollInterval: number;
maxConnectionRetries: number;
envVars: {[key: string]: string};
};
Launched chrome interface
.launch().then(chrome => ...
chrome.port: number;
chrome.kill: () => Promise<void>;
chrome.pid: number;
chrome.process: childProcess
ChromeLauncher.Launcher.defaultFlags()
Returns an Array<string>
of the default flags Chrome is launched with. Typically used along with the ignoreDefaultFlags
and chromeFlags
options.
Note: This array will exclude the following flags: --remote-debugging-port
--disable-setuid-sandbox
--user-data-dir
.
ChromeLauncher.Launcher.getInstallations()
Returns an Array<string>
of paths to available Chrome installations. When chromePath
is not provided to .launch()
, the first installation returned from this method is used instead.
Note: This method performs synchronous I/O operations.
.killAll()
Attempts to kill all Chrome instances created with .launch([opts])
. Returns a Promise that resolves to an array of errors that occurred while killing instances. If all instances were killed successfully, the array will be empty.
import * as ChromeLauncher from 'chrome-launcher';
async function cleanup() {
await ChromeLauncher.killAll();
}
Examples
Launching chrome:
import * as ChromeLauncher from 'chrome-launcher';
ChromeLauncher.launch({
startingUrl: 'https://google.com'
}).then(chrome => {
console.log(`Chrome debugging port running on ${chrome.port}`);
});
Launching headless chrome:
import * as ChromeLauncher from 'chrome-launcher';
ChromeLauncher.launch({
startingUrl: 'https://google.com',
chromeFlags: ['--headless', '--disable-gpu']
}).then(chrome => {
console.log(`Chrome debugging port running on ${chrome.port}`);
});
Launching with support for extensions and audio:
import * as ChromeLauncher from 'chrome-launcher';
const newFlags = ChromeLauncher.Launcher.defaultFlags().filter(flag => flag !== '--disable-extensions' && flag !== '--mute-audio');
ChromeLauncher.launch({
ignoreDefaultFlags: true,
chromeFlags: newFlags,
}).then(chrome => { ... });
Continuous Integration
In a CI environment like Travis, Chrome may not be installed. If you want to use chrome-launcher
, Travis can install Chrome at run time with an addon. Alternatively, you can also install Chrome using the download-chrome.sh
script.
Then in .travis.yml
, use it like so:
language: node_js
install:
- yarn install
before_script:
- export DISPLAY=:99.0
- export CHROME_PATH="$(pwd)/chrome-linux/chrome"
- sh -e /etc/init.d/xvfb start
- sleep 3
addons:
chrome: stable