How to perform unit testing

I am kind of new to the whole concept of testing. I recently watched a beginner tutorial on Traversy media's YouTube channel which gave me a basic understanding of unit testing. He basically showed how he imports app.js to his test file and then access and runs all the functions from app.js in a test environment. The thing that I don't get is how I am supposed to import my code to the test file. Pretty much all my code is rapped in the route cb function. Thanks in advance :)

Submitted September 01, 2018 at 06:00PM by everek123