Whenever you create a new software, there is a business dependency inherent on that. Obviously, if your software were not sold, you would probably have opted for some other profession. Due to the business factor, you are always expected to make your software reliable. This can be done only after your software has passed testing. It is not that you, the programmers, will do the entire testing and kick the tester out. You will be required to do the unit testing while actually writing the code. If you unit test your code, the chances of failure decrease drastically. The unit testing should ideally be done while creating code, and an ideal timeline to unit test is as soon as some milestone functionality has been created.

To act wisely and do (unit) testing, use PHPUnit. PHPUnit is a system (application) written in your favorite PHP. It lets you write test cases for the code you write so that you can keep on checking for any error that might creep into your logic. Thus, by the time...