Book Image

RSpec Essentials

By : Mani Tadayon
Book Image

RSpec Essentials

By: Mani Tadayon

Overview of this book

This book will teach you how to use RSpec to write high-value tests for real-world code. We start with the key concepts of the unit and testability, followed by hands-on exploration of key features. From the beginning, we learn how to integrate tests into the overall development process to help create high-quality code, avoiding the dangers of testing for its own sake. We build up sample applications and their corresponding tests step by step, from simple beginnings to more sophisticated versions that include databases and external web services. We devote three chapters to web applications with rich JavaScript user interfaces, building one from the ground up using behavior-driven development (BDD) and test-driven development (TDD). The code examples are detailed enough to be realistic while simple enough to be easily understood. Testing concepts, development methodologies, and engineering tradeoffs are discussed in detail as they arise. This approach is designed to foster the reader’s ability to make well-informed decisions on their own.
Table of Contents (17 chapters)
RSpec Essentials
About the Author
About the Reviewers

Chapter 3. Taking Control of State with Doubles and Hooks

In this chapter, we'll learn how RSpec implements the general testing concepts of stubs, mocks, and spies with double. We'll start by implementing our own custom mocking method and use it to show off some fun tricks. This will help us understand how mocking works. We'll also appreciate the variety of mocking tools that RSpec offers after we implement one of our own. Then we'll learn how to use RSpec hooks to set up and tear down state related to our tests. Here is what we will cover in this chapter:

  • The role of stubs, mocks, and spies in testing

  • How to use RSpec's double

  • Spying on methods and objects with expect and to_receive

  • Setup and teardown with before and after hooks