The tests for this project are built using Navigator, a Ruby testing framework for Sass with Compass. https://github.com/Team-Sass/navigator
Navigator works through Ruby, so you need to be running Ruby 1.8.7 or greater, and you to install Bundler with gem install bundler or, for Mac OS X and other systems requiring administrative privileges, sudo gem install bundler.
Once Bundler is installed, run bundle install to install libraries required by this project.
Once you have everything installed, run bundle exec rake to run the tests. This will compile all of the files in your tests/tests files into CSS files and compare those files to the files in tests/controls. If any of your output file from your tests don't line up with your controls, you'll get a .diff file generated of the differences and you'll get a failed assertion. If your Sass won't compile, you'll get a failed assertion.
If you're working off of a known set of good output and you'd like to generate your controls quickly, you can run bundle exec rake compile.