[Python-Dev] PEP: Consolidating names in the `unittest` module

[Steven D'Aprano]

On Wed, 16 Jul 2008 08:13:22 am Guido van Rossum wrote:

> > Tests in the standard distribution which use the deprecated 
> > style will need to be converted.  Steven d'Aprano claims this is
> > nontrivial (and thus error- prone) in some cases.  I haven't seen
> > that claim denied, and it seems plausible to me.
>
> I'd like to see examples of that (this would be Steven's task if he's
> serious about his assertion). Since the fail and assert names are
> mapped to each other using aliasing I don't see how it could be
> nontrivial to map e.g. self.failIf(x) to self.assertFalse(x) -- these
> are the same function!

I have not knowingly claimed that mechanically swapping fail* to assert* 
tests was difficult. The difficulty I refer to is about readability and 
understanding of the code. I often think about tests as sequences of 
possible failures, and as such my unit tests are most naturally written 
as fail*. It is that mental effort of reversing the sense of the tests 
when reading and writing assert* tests that I refer to.

If you want to declare that fail* must go, I'll be disappointed but life 
will go on. But despite the claims of those who have asserted (pun 
intended) that fail* tests are always more difficult to understand, 
that's not the case for everyone.



-- 
Steven