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)

Chapter 1: Exploring React Testing Library

React Testing Library is a modern tool for testing the UI output of React components. It abstracts a lot of boilerplate code, allowing you to write code that is easier to read, and allows you to test the code. The library encourages you to move away from testing implementation details, to avoid many false negative and false positive test cases. Instead, the library's API of tools makes it easy for you to write tests that simulate actual users' behaviors with your components, yielding confidence that the application works as expected for users. Also, because the library urges you to focus on the user when writing tests, you don't need to continuously update tests that fail when you refactor the code's implementation details. The React Testing Library allows you to write tests that fail when critical functionality unexpectedly changes, thus providing more value.

By the end of this chapter, you will understand what the...