Minimal WebDriver that pipes stdin to browsers

Minimal WebDriver

Pipe scripts to browsers using the Selenium WebDriver protocol.

  • SauceLabs support
  • Selenium Server 2 support
  • Concurrent test runs
  • No web server required
npm install min-wd

Put a config file name .min-wd in your project directory:

  "hostname": "localhost",
  "port": 4444,
  "browsers": [{
    "name": "internet explorer",
    "version": "10"
  }, {
    "name": "chrome"

Alternatively, add a webdriver property with the configs to your package.json file.

Assuming my-script.js contains this:

console.log('Hello %s!', 'browser');

Use with browserify:

$ browserify -p min-wd my-script.js
# internet explorer 9:
Hello browser!
# chrome *:
Hello browser!

Export your SauceLabs credentials:

export SAUCE_USERNAME="your-user-name"
export SAUCE_ACCESS_KEY="your-access-key"

Enable SauceLabs in your .min-wd file:

  "sauceLabs": true,
  "browsers": [...]

By default, min-webdriver will folk a new browser and inject the given script straight away without loading any web page. If you want to run your test cases in the context of a web page, you can configure the start page in the .min-wd file:

  "url": "http://my-test-page"

Testing with Mocha requires mocaccino:

$ browserify -p mocaccino -p min-wd my-test.js

If this is your use case, make sure to give Mochify a try.

The default timeout for the log polling script is 10 seconds. If you have long running test cases that don't print anything for more than 10 seconds, you can increase the timeout by adding a timeout property to your config:

"timeout": 20000

Use min-wd programatically with browserify like this:

var browserify = require('browserify');
var minWd = require('min-wd');
var b = browserify();
b.plugin(minWd, { timeout : 0 });
  • sauceLabs whether to run tests with saucelabs. Defaults to false.
  • hostname the host to connect to. Defaults to localhost. If sauceLabs is true, ondemand.saucelabs.com is used.
  • port the port to connect to. Defaults to 4444. If sauceLabs is true, 80 is used.
  • timeout if a script does not respond to log polling calls for this amount of milliseconds, the test run is aborted. Defaults to 10 seconds.
  • url the URL to open in each browser. Defaults to no URL.
  • closeOnSuccess whether to close browsers on success. Defaults to true.
  • closeOnError whether to close browsers on error. Defaults to true.
  • browsers an array of browser config objects, each with these properties:
    • name the name of the browser to launch, e.g. chrome, firefox or internet explorer
    • version the browser version to launch. Use * for any.
    • url an optional URL to launch for this browser

min-webdriver injects your script directly into the default page launched by the Selenium driver. In some cases browsers behave strangely in this context. Work around this by specifying a URL to a simple web page that is loaded before running the tests:

  "browsers": [{
    "name": "Internet Explorer",
    "version": "9",
    "url": "http://my-server/doctype.html"

With this content in the doctype.html:

<!DOCTYPE html><html><head><meta encoding="utf-8"></head><body></body></html>

You can also specify a "url" for all browser on the root level.

Loading a page before injecting the scripts is solving these issues:

  • IE 9 reporting it can't find JSON because the Selenium default page makes IE switch to quirks mode
  • Error: SECURITY_ERR: DOM Exception 18 because setting cookies is not allowed for file:// URLs
  • Error: access to the Indexed Database API is denied in this context
  • localStorage being inaccessible.
  • Node 0.10 or later
  • Selenium Server 2.39 or later