React Quickly

Chapter 16. Unit testing React with Jest

This chapter covers

• Reasons to use Jest
• Unit testing with Jest
• UI testing with Jest and TestUtils

In modern software engineering, testing is important. It’s at least as important as using Agile methods, writing well-documented code, and having enough coffee on hand—sometimes even more so. Proper testing will save you from many hours of debugging later. The code isn’t an asset, it’s a liability, so your goal is to make it as easy to maintain as possible.

Code is a liability?

Googling the phrase “Code isn’t an asset, it’s a liability” gives 191 million results, which makes it hard to pinpoint its origins. Although I can’t find an author, I can tell you the gist of the idea: when you write ...