Richard Bucker

TDD in the small?

Posted at — Jan 7, 2015

I have not deviated from the belief that TDD is junk or at least less useful than some dedicated QA engineers would have you believe. It has always been my position that the more complex a function or task the more testing might be required. When I’m building transactional system I typically build transactions to explore and explode the edge cases… partly to verify the intended functionality but also to provide a framework for regression testing.Transactional regression testing in the payments industry is critical to success but that does not make it TDD. So I have the following questions:1) how small (LOC or some complexity indicator) does a function have to be in order to justify not implementing tests?2) how big (LOC or complexity) does the function have to be in order to warrant 100% code coverage?One could argue the 1 & 2 are the same number but that’s not the point I’m trying to make. Is there a level of complexity that does not need to be tested and a level of complexity that MUST be tested?