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

Compiling the schema before you begin

The code samples for this chapter already contain some additions:

  • The react-relay, relay-compiler, and babel-plugin-relay packages.
  • Babel configuration to ensure your build understands the new GraphQL syntax.
  • Relay configuration in the relay.config.json file. The primary piece of configuration is the location of the schema.
  • A GraphQL schema in the file src/schema.graphql.
  • A server endpoint at POST/graphql, which services incoming GraphQL requests.

It’s beyond the scope of this book to go into each of these, but you will need to compile the schema before you begin, which can be done by typing the following command:

npx relay-compiler

The npm run build command has also been modified to run this command for you, just in case you forget. Once everything is compiled, you’re ready to write some tests.