Testing is a vital part of any development process. Whether a project's authors are hoping for scalability, fewer bugs, or just code that stands the test of time, a solid test suite is essential.
It's all well and good writing tests, but how do you know that you've tested the code that matters? Did you cover the most important components? Did you test the sad path? The edge cases? What about the zero states?
Using Istanbul, you can generate a nice coverage report to answer these questions. In this article, we'll look at how to get it set up in a typical clientside JS project.