Learn to test with confidence

Learning to test your Ruby and Rails code can be tough. Even after you've been through blog posts and tutorials, screencasts and demo apps, you might find yourself feeling more lost than ever.

Ruby and Rails developers emphasize testing for good reasons, and you want to get on board, but even so, it can be damn hard to learn. You just want to write tests that tell you when you're breaking something, run fast, and guide you in your work.

Introducing: The Minitest Cookbook

If you want to use even the most simple tool effectively, you need to know how to hold it. That's why I'm writing The Minitest Cookbook - to help Ruby and Rails developers at all skill levels master the techniques they need to write clear, maintainable tests and help others to do the same. That process begins with a set of fundamentals where you'll learn how to:

  • Write tests using both assertions and specs
  • Structure your tests for clarity and confidence
  • Validate your code with assertions and expectations
  • Use mocks, stubs, and other kinds of test doubles
  • Effectively manage test data
  • Share common code between tests
  • Run one test case or your whole suite

Once you've covered the basics and your feel you're ready to move to the next level, we've got you covered, and so does Minitest. Because even though it's compact, Minitest is also super flexible and ready to test whatever sort of Ruby code you want to throw at it. It's based around a simple architecture and supports customizations via plugins, so you'll be able to trick out your testing stack with third-party gems from a large and growing ecosystem of plugins. Later sections of the book will deal with advanced topics on a deeper level including how to:

  • Test your Rails applications from top to bottom
  • Customize your test reports with better, more actionable information
  • Cover hard-to-reach code that you couldn't test before
  • Write custom assertions and expectations specifically for your application
  • Build and release your own framework extensions

Why Minitest?

Minitest is a full-featured framework for automated testing that supports both assertion-style and spec-style tests along with basic mocking, performance benchmarking, parallelization, and a simple plugin architecture. All this in around 1500 lines of code compared to over 12,000 for RSpec.

Keeping things simple is the whole point, and it's one major reason why a lot of developers have been drawn to Minitest. It takes a restrained approach by providing developers with a minimal set of standard assertions and expectations that they can use to test their code or build on with their own creations. For you the developer, that means:

Table of Contents

  • Introduction
  • How Minitest Works
  • Add Minitest to a Ruby Project
  • Running Your Tests
  • Writing Tests and Specs
  • Configuring Pre-Test State
  • Comparing Things
  • Having Fun with Minitest::Pride & Friends
  • Using Mocks, Stubs and Test Fakes
  • Customizing Test Reports
  • Testing Mixin Behavior
  • Sharing Code Between Tests
  • Continuous Testing
  • Custom Assertions and Expectations
  • Developing Your Own Extensions
  • Adding Minitest to a Rails Project
  • Managing Test Data
  • Testing Rails Models
  • Testing Rails Controllers
  • Testing Rails Helpers
  • Testing Rails Background Jobs
  • Testing Your Rails Application End-to-End

About the Author

I'm Chris Kottom, and I've been working on the web since the mid-90s. In 2006, feeling burned out after 10 years as a Java developer, I rediscovered my love of coding through Ruby on Rails, and I've been at it ever since.

Like a lot of new arrivals to the community, I liked the integration of tests as first-class citizens of the framework, but at that point, I had almost no experience with test automation. So after years of faking it, I decided to make writing great tests my super power and to help other developers learn to do the same.

Get in touch with questions or comments via email or Twitter.