Resig has a bunch of unit tests he does to make sure jQuery works properly on whatever browser. Manually running and checking unit test results is annoying and time consuming. Let's automate this.

Combine something simple like Firefox and Xvfb (X Virtual Frame Buffer), and you've got a simple way to run Firefox without a visible display.

Let's start Xvfb:

startx -- `which Xvfb` :1 -screen 0 1024x768x24

This starts Xvfb running on :1 with a screen size of 1024x768 and 24bits/pixel color depth. Now, let's run firefox:

DISPLAY=:1 firefox

# Or, if you run csh or tcsh
env DISPLAY=:1 firefox

Seems simple enough. What now? We want to tell firefox to go to google.com, perhaps.

DISPLAY=:1 firefox-remote http://www.google.com/

Now, let's take a screenshot (requires ImageMagick's import command):

DISPLAY=:1 import -window root googledotcom.png

Lets see what that looks like: googledotcom.png

While this isn't complicated, we could VERY EASILY automate lots of magic using something like the Selenium extension, all without requiring the use of a visual display (Monitor). Hopefully I'll find time to work on something cool using this soon.

Problems with screen scraping and other website interaction automation is that it almost always needs to be done without a browser. For instance, all of my screen scraping adventures have been using Perl. Browsers already know how to speak to the web, so why reinvent the wheel?

Firefox has lots of javascript-magic extensions such as greasemonkey and Selenium to let you execute browser-side javascript and activity automatically. Combine these together with Xvfb, and you can automate lots of things behind the scenes.

Tie this back to unit tests. Instead of simply displaying results of unit tests, have the page also report the results to a cgi script on the webserver. This will let you automatically test websites using a web browser and have it automatically report the results back to a server.