Cucumber has come a long way since I’ve first started to use it. My two posts about getting started with BDD have been the most visited pages of my blog. So it seems only fitting to address the new features and update the material. I’ll be creating a series of blog posts (so it doesn’t end up being one giant scrolling page) addressing a real-life situation of creating a contact management feature. We’ll build it from the ground up using Cucumber and RSpec.
Installing Cucumber / RSpec
The first step to using Cucumber (and RSpec) is to install the necessary gems. This is very straightforward and probably familiar to most people:
sudo gem install rspec rspec-rails cucumber cucumber-rails webrat ZenTest database_cleaner
If you are using Ruby > 1.9 you will also need to install the test-unit gem (or RSpec will not load properly).
sudo gem install test-unit -v=1.2.3
Now if you run into errors installing webrat, know that it requires nokogiri (an awesome XML parser, see my blog post about nokogiri). In order to build nokogiri though you need to have a few libraries installed ahead of time. If you run into any errors installing webrat (likely because it couldn’t install the dependency nokogiri gem) try the following (I’m using a Debian -Kbuntu- flavor of Linux, so your specific command might vary):
sudo aptitude install libxml2-dev libxslt1-dev
Once you have installed the two developer libraries for libxml2 and libxslt you can try to reinstall webrat (sudo gem install webrat) and it should properly build.
Adding RSpec and Cucumber to a Rails Project
Having the gems installed is the first step. To use Cucumber in your Rails project you need to run a few generation scripts which prime your application and make a few config updates. Run the following commands from inside your Rails application root:
script/generate rspec script/generate cucumber
These scripts create new rake tasks, a spec and feature folder, as well as modify your database.yml (adding a new cucumber environment). You’ll also notice a new cucumber environment file added to your environments folder already completed with all the necessary config.gem entries, nice.
That’s all there is to it for getting started. Next post I will talk about outside-in development and starting your first feature!
