Testing (i.e. linting, unit tests, integration testing etc..) client-side code is not done as commonly as it should be. The reason it is so commonly not done, besides lack of know-how, is that it is presupposed that it will take time away from other more productive development tasks.
This fallacious notion is, of course, wrong. The repeatable successes in software engineering based on testable (i.e. modular, loosely coupled, small, simple units of code) and tested code has proven again and again to be a time-saver and part of creating maintainable and understandable code. At a minimum, if code is not unit tested it is only a matter of time before it is burnt down and re-written, or abandoned altogether because it becomes unmaintainable and incomprehensible.
In this article, I am going to defend and talk about testing client-side code. It is my intention that the information in this article will give those among us who do not test, the desire and some initial testing knowledge to test, along with the ability to defend its necessity from any agent that might deter testing.
Via Jan Hesse