with us developers crying for our right and the four reason why you want to write your test first it's one of a mechanical reason because seen a test fail is the test that tests that the test test what is supposed to test or in simple words how do you know that your test doesn't have any bug if you write a test and you see it right there is a strong indication that is some piece of production code some logic that is not there if you write the test and you never say bread what you don't know if it is because you're ready