Rails 5 Test Prescriptions

Getting Started with Minitest

Installing Minitest itself is easy: do nothing.

Minitest is part of core Ruby, and the Rails extensions I cover here are part of the core Rails bundle.

However, a couple of add-on libraries you’ve come across so far in this book require specific installations for Minitest. Minitest’s included test-double package, Minitest::Mock, is small and lacks some useful features. I’ll demonstrate test doubles using Mocha, which is the package the Rails team uses.^[53]

To install Mocha, place the following in the Gemfile in the development test group:

gem "mocha", require: false

Minitest uses the test/test_helper.rb file to store setup. You’ll need to load Mocha in that file:

minitest/01/test/test_helper.rb

require ...