Re: [PATCH] CONTRIBUTE - writing tests for understanding internals

[Przemysław Wojnowski]

W dniu 12.11.2015 o 21:55, Eli Zaretskii pisze:
> In TDD, they teach you to write a test for a spec that isn't
> implemented yet.  The test fails, of course (which is a Good Thing:
> now you know that your test indeed will catch a non-compliant
> implementation), and then you implement the spec to see that it now
> succeeds.  If you work that way, tests _do_ drive the development.

What do you mean by "spec" here?

I've never seen nor used TDD (and I use it very often) with "spec".
What I've seen, though, was using TDD to implement User Stories (Use
Cases), which are descriptions of functionality, but far from formal
specifications - if this is what you mean.

Anyway, TDD drives design (you implement only as much as is needed to
make the tests pass) and, by side effect, gives strong regression test
suite, which _enables_ refactoring.
Many TDD practitioners say that its result is good API.