Does your Rails code suffer from bloat, brittleness, or inaccuracy? Cure these problems with a regular dose of test-driven development. 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 and Cucumber. Do what the doctor ordered to make your applications feel all better. Side effects may include better code, fewer bugs, and happier developers.