JavaScript Unit testing is a method in which a JavaScript test that is written for a web page or web application module is combined with HTML as an inline event handler and executed in the browser. The tests are then organized in the test suite.
The suite contains a set of tests for verifying individual modules. It should be executed in a specified order, but it does not depend on other tests’ results. It can be executed as frequently as necessary without causing delays in running other tests.
There are many JavaScript unit testing frameworks that can be used, including Jest, Mocha, Jasmine, etc.