Enhancing Jest assertions with jest-dom

jest-dom is a utility tool from the DOM Testing Library that provides extra Jest assertions to use in tests. In this section, you will learn how to install jest-dom and understand the advantages of using jest-dom with Jest.

Adding jest-dom to a project

Add jest-dom to a project that includes Jest using the following steps:

1. Install the package using npm:

   npm install –-save-dev @testing-library/jest-dom

2. Add the following snippet to the top of your test file:

   import '@testing-library/jest-dom/extend-expect';

After installing and importing jest-dom into your test file, you can start using the extra assertions as they are now chained off the expect method. You will see detailed illustrated use cases in the next section.

Advantages of using jest-dom with Jest

You can enhance user-focused testing goals by including jest-dom in React projects that use Jest. jest-dom provides two significant enhancements for...