With some experience, I find it impossible to write code using TDD that is difficult to refactor. Good code, that scores well on SOLID metrics, is easy to refac

With some experience, I find it impossible to write code using TDD that is difficult to refactor. Good code, that scores well on SOLID metrics, is easy to refactor, because individual pieces are already split out into multiple classes, rather than living as a series of statements in a single method in a single class. >One of the common pitfalls with TDD and unit-testing is that you end up having a function that's sufficiently well covered with unit tests, but as it evolves into something more complex, A function should not evolve into something more complex. It should be split out into multiple functions, each of which is simple. In addition to being far easier to test individually, you will find that when you need to change it, only some parts will need to be discarded.