Here’s a list of Rails gems that have been helpful in testing for me:
RSpec Rails – for using the RSpec framework for testing
Capybara – for testing the app like a visitor would interact with the web app
Factory Girl Rails – makes it easy to create instances of models and associations
Shoulda Matchers – makes it easier to test and verify things with methods that use easy to understand language
Database Cleaner – to help keep your test environment from having a bunch of extra and redundant data
Guard – allows me to automatically test the code and specs that I change so I don’t need to remember to manually kick off a test each time a change is made
Launchy – useful with Capybara tests when I can’t figure out why a test is failing. Launchy launches a browser so you can see the contents of the page.’save_and_open_page’ line to your spec when you want to do this.