Clean Code in JavaScript

Unit testing

As we described with our car analogy, a unit test is a test that deals with an isolated unit of code. This will usually be either a singular function or module that will make one or more simple assertions about the operation of the code.

Here are some examples of singular unit test scenarios:

• You have a Button component that should contain the value Submit My Data and should have a class of btn_success. You can assert these characteristics via a simple unit test that checks the attributes of the produced DOM element.
• You have a task-scheduling utility that will perform a given action at the requested time. You can assert that it does so by giving it a task to perform at a specific time and then checking for the successful execution ...