I'm curious how much time was spent trying to write test driven code before deciding it wasn't working for you. Did you succesfully write a few small programs u

I'm curious how much time was spent trying to write test driven code before deciding it wasn't working for you. Did you succesfully write a few small programs using TDD (coding katas)? Or did you apply TDD to your project at work? For how many hours or lines of code did you try TDD before deciding it wasn't going to work?