RSpec Rails brings the RSpec testing framework to Ruby on Rails as a drop-in alternative to its default testing framework, Minitest. In RSpec, tests are not just scripts that verify your application code. They’re also specifications (or specs, for short): detailed explanations of how the application is supposed to behave, expressed in plain English. RSpec follows semantic versioning, which means that “major version” upgrades (e.g., 2.x → 3.x) come with breaking changes. If you’re upgrading from...