Here is an exchange from another discussion of this topic
> So, looking from this angle, you came to the heart of programming.
> Unit tests is a reference/control info to incrementally build-up
> a program - 'configure' a programmable material.
I agree. We already have these really cool controllers. They are called human beings :-)
Human controllers have all kinds of ideas and desires, but we aren't real good at maintaining attention, and handling myriad details. So we need help. Unit tests are that help. They are as flexible as their human controllers make them. The collaboration of humans and @test is superb: each can do what it does best.