> It also assumes a bug free app with 100% code coverage is the objective, regardless of the cost it takes to write all that test code. I disagree on this. 100

> It also assumes a bug free app with 100% code coverage is the objective, regardless of the cost it takes to write all that test code. I disagree on this. 100% coverage is actually a bad thing, in my opinion, because there's always a lot of code you do not need to test (simple constructors, accessors/mutators, etc). A unit test should test things that you are relying on being correct. You write a unit test as a way to protect future developers (including yourself) from totally screwing things up by accidentally changing something important. An application with a few bugs that took half the resources to develop is nice- until the customer needs a few extra changes 18 months later, and you turn 'a few' bugs into 'a whole lot of' bugs.