Re: call for more ert tests

[Lars Magne Ingebrigtsen]

Óscar Fuentes <address@hidden> writes:

> Eli Zaretskii <address@hidden> writes:
>>
>> I believe it's good, obviously.  The problem is with introducing it
>> without losing too many contributors.

I think the bar to contributing to Emacs is high enough as it is without
adding further requirements.

> I wonder about the possibility of making Emacs testing an "interesting"
> task. Something like a test framework which is complete and expressive
> enough to allow describing testable conditions on a very high level way.

ert is fine, but, I think, somewhat misguided.  It allows us to test the
functions we have Lisp interfaces for, but not the deep internal C
bits.  And that's kinda backward.

When I write Lisp code, I'm testing it interactively all the time.  What
should this function return?  Does it return what I'm expecting?  No?
*hack hack*  Now?  Yes.  Done.

You really need a test harness more for languages where you don't have
that extremely rapid and natural write-test-write cycle, because nobody
can test stuff that requires a compile (or startup) cycle as
thoroughly as that.  For instance, when I wrote the
:max-width/:max-height code the other day, the result depends on six
different things: image width/height, and the four
:width/:height/:max-width/:max-height parameters.

If I could have called that function from Lisp directly, I would have
tested a much larger variety of combinations than I ended up doing.

So my feeling about adding more ert tests is: Meh.  More work to write,
more work to maintain, doesn't really give us that much.

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/