I cannot disagree with following opinion about unit testing, and I also find it is especially right with Vietnamese developers who can close a bug without a quick re-test, even without a build . Quoted from http://stackoverflow.com/questions/962887/do-you-have-the-time-to-write-unit-tests

The real benefit is that developers become responsible for the quality of their work. Verifying proper behavior of your work isn’t the responsibility of some tester – it’s up to you. If you’re finding problems before you integrate your code it’s far better than letting it go downstream and finding out later.