Does your Rails code suffer from bloat, brittleness, or inaccuracy? Cure these problems with the regular application of test-driven development. You'll use Rails 5.1, Minitest 5, and RSpec 3.6, as well as popular testing libraries such as factory_girl and Cucumber.
The Pickaxe Book, named for the tool on the cover, is the definitive reference on Ruby, a highly-regarded, fully object-oriented programming language. This updated edition is a comprehensive reference on the language itself, with a tutorial on the most important features of Ruby.