We start with a new Rails 5 application and configure all the necessary tools for effective BDD, including RSpec and Cucumber. We also get to the first green CI build on Semaphore.

An excerpt from Rails Testing Handbook (free ebook, see tutorial for link).
How much do Rails developers really write tests? Take a data-driven look into test coverage and CI speed of commercial Rails apps running on Semaphore.
Tired of fragile code? This hands-on book will teach you how to build better Rails apps with confidence. Learn practical BDD from the makers of Semaphore.