Wednesday, April 06, 2011

Cucumber with Celerity and Watir-Webdriver

Earlier this year, I had the problem of trying to enable our QA staff to run our current suite of Celerity driven Cucumber tests through the actual browsers that we were using.  One obvious solution is to use various flavors of Watir.

The main concern with this solution is that Waitr required native ruby instead of jruby.  Not a huge deal, but still an extra annoyance for folks in a java shop.  Requiring QA to switch between jruby and watir wasn't ideal.  Additionally, taking snapshots of the screen during a failed test was far from trivial.

So instead, I embarked on a quest to use watir-webdriver and Celerity together.  The advantage here is that watir-webdriver, through selenium-webdriver, can talk to browsers and runs on jruby.  This combination was alluded to on several blog sites that I had found, but I never quite found something that put it all together for me.   Eventually, i got it working. Hopefully this will at least get you about 90% of the way there.

The first step would be adding watir-webdriver to your Gemfile:

Following that we create a browser.rb file that determines what sort of browser you are running.  I placed this in the support folder in the Cucumber project.  One thing to remember about this, is that you could also throw this method into your env.rb.

What's going on here? We're using the environment variable BROWSER to determine if we want to run something in a browser.  We then use another environment variable to determine which browser to use.  We even have an environment variable to determine what Firefox we want to use, which is a nice feature of selenium-webdriver.  At the end, Browser contains the class of browser we want to instantiate for tests, and BROWSER_TYPE contains the actual type of browser to instantiate for watir-webdriver.

One other thing to note, when we use Celerity, we're setting the offset for index based searches to 0.  Unlike watir-webdriver, Watir uses 1th based arrays.  Celerity, being a wrapper of HtmlUnit, had to translate those arrays from 1 to 0 so that HtmlUnit would run properly.  By setting this value, we can use 0th based arrays, just like watir-webdriver does in Celerity.

Next we setup our Cucumber Before block in hooks.rb:

In here, we simply instantiate the object.  In my case, we also needed to setup some URLs and turn off SSL for our Celerity testing.

The Rakefile is probably a bit more complex due to our desire to run both headless and browser tests on our CI box, but it is helpful, since it uses the :browser task to setup the BROWSER environment variable.

Finally, to help our QA folks, three batch files to execute the tests.

Hopefully you'll find this useful. Please let me know if you do.

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