[narrator]

The thing about TDD is it lets you figure out where you were in a big complicated thing you're implementing. That's the hardest part sometimes about programming. Answering the question: Where was I? What did I have to do next? Especially when the system is non-trivial.

It's like writing very detailed functional notes to yourself about what your program is actually supposed to do so you can implement it. Besides, you write twice as much code, but have half as many bugs. It's a big win all around.

I wonder what it would be like to take TDD to extremes and write all the tests for the minimum viable product before writing a single line of actual implementation code. I wonder if it would be possible. It would certainly help me pick up a project wherever I had left it at any time in the future.