Have you ever made some changes to your code, and later found it caused something else to break?
I’m sure most of us have. This is almost inevitable, especially when you have a larger amount of code. One thing depends on another, and then changing it breaks something else as a result.
But what if that didn’t happen? What if you had a way of knowing when something breaks as a result of some change? That would be pretty great. You could modify your code without having to worry about breaking anything, you’d have fewer bugs and you’d spend less time debugging.
That’s where unit tests shine. They will automatically detect any problems in the code for you. Make a change, run your tests and if anything breaks, you’ll immediately know what happened, where the problem is and what the correct behavior should be. This completely eliminates any guesswork!
In this article, I’ll show you how to get started unit testing your JavaScript code. The examples and techniques shown in this article can be applied to both browser-based code and Node.js code.