How to install the Shoulda rails testing framework
So you’ve decided to start using Shoulda instead of Rspec or Test::Unit in your latest rails project? There’s one step you might not think to do, which strangely is absent in any of the Shoulda documentation.
After you `sudo gem install thoughtbot-shoulda` …
Don’t forget to put require ’shoulda’ at the top of whatever test classes you write, otherwise you’ll get “undefined method `should`” all over the place. There, I saved you 4 hours.

Micah Said,
January 7, 2009 @ 5:15 pm
Just put it once in test_helper.rb That’s for universal includes like shoulda.
Tammer Saleh Said,
January 7, 2009 @ 8:38 pm
You can also put that line in environments/test.rb (if this is a rails app).