The initial beta of Rails 4 Test Prescriptions by Noel Rappin from Pragmatic is now on sale.

Rails 4 Test Prescriptions is a comprehensive guide to how tests can help you design and write better Rails applications. In this completely revised edition, you’ll learn why testing works and how to test effectively using Rails 4, Minitest 5, and RSpec 3, as well as popular testing libraries such as factory_girl, Capybara and Cucumber.