I have been looking at the unit testing topic and honestly I have never yet seen it in a live application.
Im a little foggy on the subject….
A simple example is if I am populating a listbox with data, I would know through debugging if the data is being populated and if it wasnt it would probably be easy to figure out why. Futhermore I couldnt possibly put it in production if it wasnt work so, why would I need to do a unit test? I dont see the point of it.
What if you were working on an entirely different area of the site, but because of the way your code was constructed, the changes you made broke the code that fills the listbox with data? How long would it take you to discover that? Worse, what if it was someone else on the team who made such a change; someone who had no idea how the listbox-filling code worked at all? Or even someone who didn’t know there was code to fill listboxes?
Unit testing gives you a set of tests that ensure you never regress and introduce bugs in areas of your program that have already been proven to work, because you run the unit tests after every change and refactoring. Unit testing lets you program without fear.
Furthermore, by designing your code to be testable, you necessarily create a loosely-coupled architecture that follows a large list of best practices, e.g. dependency injection.