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 4

  1. Testing integrated components allow you to mitigate risk by verifying production behavior when components interact with each other. Using the isolated approach, we would be replacing real dependencies with fake data and responses and, therefore, not mitigate as much risk. Also, in many situations, you can cover more code in fewer tests using the integrated testing approach.
  2. You should only use the data-testid attribute as the last resort when other preferred queries methods such as getBy* and findBy* cannot be used to select elements.
  3. The act method ensures your tests behave closer to how React updates the browser's DOM. Use act in situations where you need to manually make component updates such as resolving a Promise that React otherwise would not be aware of in your test. React Testing Library automatically wraps components in act eliminating the need to manually wrap all code that updates the component in most scenarios, such as click events.
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