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)

Writing Tests using Cypress design patterns

In the previous section, we learned how to use Cypress to drive the development of new features to a blog application. In this section, we will look at two design patterns to structure our Cypress code. Design patterns help teams by providing solutions to problems such as writing maintainable code or designing responsive websites. First, we will look at the Page Object Model, followed by custom commands.

Creating page objects in Cypress

The Page Object Model (POM) is a popular design pattern commonly used in Selenium test frameworks to increase readability and maintainability for end-to-end tests. The POM model consists of creating an object-oriented class representation for each page in an application, including custom methods to select and interact with various page elements. An advantage of using the POM model is abstracting away multiple lines of test code inside a single method.

Also, page objects serve as a single source of...