Re: master 262d0c6: Mark some tests as expensive

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Daniel Martín <mardani29@yahoo.es>,
>   michael.albinus@gmx.de,
>   stefan@marxist.se,  emacs-devel@gnu.org
> Date: Sat, 12 Sep 2020 13:15:06 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I also don't understand the more general issue with how long the test
> > suite runs.  While it runs, you can do something useful on a modern
> > system (or just go for a coffee), so why does it matter?
> 
> I appreciate a fast test suite -- I often do a "make check" before
> pushing just to see that nothing was inadvertently broken by a
> seemingly-innocuous change.

How will that work if the change was in Tramp, or was related to
Tramp?  In my case, for example, it would most probably mean none of
the Tramp tests will ever run at all, because they all take more than
1 sec down here.

Also, there are some tests with inherent delays (auto-revert tests are
one example, but there are others) -- would that mean we don't run
these, either?

What I do for a "fast test" use case is to run only the tests directly
related to the change, usually the FOO-tests.el tests that correspond
to the file FOO I've changed.  Sometimes, there are related tests in
other files as well.  A simple "make FOO-tests" command is all that's
needed.

IOW, I don't think the time to run the tests is a good criterion, at
least not if applied globally to the entire suite.