Book Image

Simplify Testing with React Testing Library

By : Scottie Crump
Book Image

Simplify Testing with React Testing Library

By: Scottie Crump

Overview of this book

React Testing Library (RTL) is a lightweight and easy-to-use tool for testing the document object model (DOM) output of components. This book will show you how to use this modern, user-friendly tool to test React components, reducing the risk that your application will not work as expected in production. The book demonstrates code snippets that will allow you to implement RTL easily, helping you to understand the guiding principles of the DOM Testing Library to write tests from the perspective of the user. You'll explore the advantages of testing components from the perspective of individuals who will actually use your components, and use test-driven development (TDD) to drive the process of writing tests. As you advance, you'll discover how to add RTL to React projects, test components using the Context API, and also learn how to write user interface (UI) end-to-end tests using the popular Cypress library. Throughout this book, you’ll work with practical examples and useful explanations to be able to confidently create tests that don't break when changes are made. By the end of this React book, you will have learned all you need to be able to test React components confidently.
Table of Contents (10 chapters)

Selecting the best queries with Testing Playground

In this section, we will learn how to use Testing Playground. This is a tool that makes it easier for you to determine the right DOM Testing Library query selector. Testing Playground allows you to paste HTML into an interactive website, which allows you to click on elements as they appear rendered in the browser. This enables you to learn which DOM Testing Library queries can be used to select a particular element.

The tool always suggests queries in order, based on the DOM Testing Library query recommendations for elements that offer multiple ways of selection. Furthermore, the tool allows you to copy the selector to use in your test code. We will look at two ways of using Testing Playground: first, via the website, and second, via a Chrome extension.

Selecting queries using the Testing Playground website

In this section, we will learn how to use Testing Playground via its website. In previous examples throughout the book...