threehv

I think Cucumber is fast becoming indispensable for my testing. The point of it is that you can write documentation that your client understands and then prove that the application does what it says. When coupled with WATIR you can show that it really works in an actual browser – you can even show it in Internet Explorer, Firefox and Safari.

There are a number of issues with using WATIR – the main one being speed – as WATIR scripts the browser, an extensive test suite will take a long time to run.

But my first hurdle was actually getting the code running. Unlike using Cucumber with Webrat, where your Cucumber steps have access to your Rails code (so you can play around with the response object), with WATIR you run the application in a separate process and then poke the browser in the same way a real user would. Of course, unlike Webrat, you get to test your Javascript too.

However, I didn’t want to have to remember to start my application before running the tests (and probably forgetting to put it into the test environment or running on the wrong port) – so I came up with the following for your features/support/env.rb.

system 'rake db:test:clone'
system 'rm log/test.log'
system 'ruby script/server -p 3001 -e test -d'

at_exit do
  system "kill `ps aux | grep mongrel_rails | grep -e '-p 3001' | grep -v grep | awk '{ print $2 }'`"
end

Before do
  @browser = Watir::Safari.new
  @browser.set_fast_speed
  @base_url = 'http://localhost:3001'
end

This clones your development database, gets rid of the test log (as we’ll need to look through that to track down any errors, so we want to keep it small) and then starts your app in test mode on port 3001 (so it doesn’t clash with the version you’ve already got open in development). The Before clause sets up WATIR and configures a base url that my steps use elsewhere. And the at_exit hook looks for the server we started and kills it.

Next step is to add a platform instruction – so you can choose to test with Safari, Firefox (if I can ever get the Firewatir plugin installed) and Internet Explorer (where I guess the kill statement will need a bit of alteration).

An alternative is to tell mongrel to start and write a pidfile to a known place, and then replace the ps/grep line with:

  pid = File.read(File.expand_path(RAILS_ROOT + "/log/mongrel.pid")).chomp
  `kill #{pid}`

Thanks to Caius for that version.

This entry was posted on Friday, January 16th, 2009 at 9:52 am and is filed under Designing Great Software, Ruby on Rails and Software Development, Writing Reliable, Bug-Free Code.