Book Image

Mastering React Test-Driven Development - Second Edition

By : Daniel Irvine
Book Image

Mastering React Test-Driven Development - Second Edition

By: Daniel Irvine

Overview of this book

Test-driven development (TDD) is a programming workflow that helps you build your apps by specifying behavior as automated tests. The TDD workflow future-proofs apps so that they can be modified without fear of breaking existing functionality. Another benefit of TDD is that it helps software development teams communicate their intentions more clearly, by way of test specifications. This book teaches you how to apply TDD when building React apps. You’ll create a sample app using the same React libraries and tools that professional React developers use, such as Jest, React Router, Redux, Relay (GraphQL), Cucumber, and Puppeteer. The TDD workflow is supported by various testing techniques and patterns, which are useful even if you’re not following the TDD process. This book covers these techniques by walking you through the creation of a component test framework. You’ll learn automated testing theory which will help you work with any of the test libraries that are in standard usage today, such as React Testing Library. This second edition has been revised with a stronger focus on concise code examples and has been fully updated for React 18. By the end of this TDD book, you’ll be able to use React, Redux, and GraphQL to develop robust web apps.
Table of Contents (26 chapters)
Part 1 – Exploring the TDD Workflow
Part 2 – Building Application Features
Part 3 – Interactivity
Part 4 – Behavior-Driven Development with Cucumber

Writing Your First Cucumber Test

Test-driven development is primarily a process for developers. Sometimes, customers and product owners want to see the results of automated tests too. Unfortunately, the humble unit test that is the foundation of TDD is simply too low-level to be helpful to non-developers. That’s where the idea of Behavior Driven Development (BDD) comes in.

BDD tests have a few characteristics that set them apart from the unit tests you’ve seen so far:

  • They are end-to-end tests that operate across the entire system.
  • They are written in natural language rather than code, which is understandable by non-coders and coders alike.
  • They avoid making references to internal mechanics, instead focusing on the outward behavior of the system.
  • The test definition describes itself (with unit tests, you need to write a test description that matches the code).
  • The syntax is designed to ensure that your tests are written as examples, and as discrete...