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)
1
Part 1 – Exploring the TDD Workflow
10
Part 2 – Building Application Features
16
Part 3 – Interactivity
20
Part 4 – Behavior-Driven Development with Cucumber

Test-Driving GraphQL

GraphQL offers an alternative to HTTP requests for fetching data. It offers a whole bunch of additional features that can be added to data requests.

As with Redux, GraphQL systems can seem complicated, but TDD helps to provide an approach to understanding and learning.

In this chapter, we’ll use the Relay library to connect to our backend. We’re going to build a new CustomerHistory component that displays details of a single customer and their appointment history.

This is a bare-bones GraphQL implementation that shows the fundamentals of test-driving the technology. If you’re using other GraphQL libraries instead of Relay, the techniques we’ll explore in this chapter will also apply.

Here’s what the new CustomerHistory component looks like:

Figure 13.1 – The new CustomerHistory component

This chapter covers the following topics:

  • Compiling the schema before you begin
  • Test...