RSpec is a very expressive testing framework with many great features and helpers to make tests readable. When writing RSpec tests, here are just a few not so obvious hints that could make tests even easier to write, read, and maintain.
In Rails 5 each migration class is inherited from `ActiveRecord::Migration[5.0]`. It looks quite unusual to see that `[5.0]` part at the end of the parent class. In this article I'll describe why we might need it and how it works.