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)

Testing components that use GraphQL

In this section, you will learn how to test components that use GraphQL to consume API data. In Chapter 3, Testing Complex Components with React Testing Library, we learned how to test components that interacted with REST APIs. The same concept to test REST API consuming components also applies with GraphQL, but with a few differences. We will use the Table component we tested in the Testing integrated components section of this chapter, only now the component will be refactored to receive data via the GraphQL server using Apollo Client (https://www.apollographql.com/docs/react/).

We can look at the implementation details of the Table component to understand how it interacts with GraphQL:

export const EMPLOYEES = gql`
  query GetEmployees {
    employees {
      id
      name
      department
     ...