Testing frontend applications overview

The main requirement when testing frontend applications based on JavaScript is having an engine that runs the tests for you. There are plenty of test runner alternatives to choose from – Mocha, Ava, and Jazmine, just to name a few. However, in Chapter 7, Bootstrapping the React Project, we created our frontend project by leveraging Create React App, which uses Jest as its test runner, and this is the one we’ll be using for our project. Jest is one of the most popular and widely adopted JavaScript testing frameworks. It’s not only a test runner, but a full-featured framework with features and tooling for mocking, assertion, verification, and so on.

One of the crucial parts of frontend testing is verifying that the page elements render correctly in the browser. This is especially critical with React since this library is all about components and managing their state. Enzyme was one of the main tools to test the React components...