Book Image

Mastering React Test-Driven Development

By : Daniel Irvine
Book Image

Mastering React Test-Driven Development

By: Daniel Irvine

Overview of this book

Many programmers are aware of TDD but struggle to apply it beyond basic examples. This book teaches how to build complex, real-world applications using Test-Driven Development (TDD). It takes a first principles approach to the TDD process using plain Jest and includes test-driving the integration of libraries including React Router, Redux, and Relay (GraphQL). Readers will practice systematic refactoring while building out their own test framework, gaining a deep understanding of TDD tools and techniques. They will learn how to test-drive features such as client- and server-side form validation, data filtering and searching, navigation and user workflow, undo/redo, animation, LocalStorage access, WebSocket communication, and querying GraphQL endpoints. The book covers refactoring codebases to use the React Router and Redux libraries. via TDD. Redux is explored in depth, with reducers, middleware, sagas, and connected React components. The book also covers acceptance testing using Cucumber and Puppeteer. The book is fully up to date with React 16.9 and has in-depth coverage of hooks and the ‘act’ test helper.
Table of Contents (21 chapters)
Free Chapter
1
Section 1: First Principles of TDD
6
Section 2: Building a Single-Page Application
12
Section 3: Interactivity
16
Section 4: Acceptance Testing with BDD

General rules for test-driving React Router

React Router is the kind of library that can cause people to "forget about" testing. Although the library itself is simple to use—it's just a collection of Router, Route, and Link components—testing can prove tricky once you get past the simple examples and into the real world.

When people hit difficulty in real-world scenarios, sometimes their response is to give up on the tests and perhaps come back to them later. Unfortunately, having holes in your test coverage can severely impact the confidence you have in your test suite, so it's important to resist that impulse to move on to the next thing.

With a little bit of perseverance and some critical thinking, testing React Router is quite feasible, as you're about to find out. In this section, I'll give you some general guidance, which you should...