Re: [PATCH 2/2] test-lib-functions: use BUG() in 'test_must_fail'

[Jeff King <peff@peff.net>]

On Tue, Apr 14, 2026 at 02:11:00PM -0700, Junio C Hamano wrote:

> I was wondering if we should remove "test_might_fail".  Its use case
> is rather limited to very narrow cases, like
> 
>  * we want to kill something but it may have exited on its own
> 
>  * we want "git config --unset" but the variable may or may not be set
> 
>  * we want "git foo --abort" just in case we are in the middle of
>    "git foo"
> 
> all of which is clearer with "|| :", and more importantly, the thing
> whose "failure" is protected against the test framework declaring a
> test failure is *not* what we are testing (these "config --unset"
> are not about testing "git config", in other words).
> 
> So the extra ability test_must_fail and test_might_fail have that
> they can detect uncontrolled death with non-zero exit status (aka
> "crash") is not very interesting---it is more like "As we are
> running a git command here, it would be better to catch than not
> catch a segfault here as well", i.e., a nice to have item.

I think the main value of both (but especially test_might_fail) is that
they slot naturally into &&-chains. I left a similar comment in that
other thread, but to expand a bit, if you do:

  false &&
  true || : &&
  echo everything ok

you will get "everything ok", even though step 1 failed. You need:

  false &&
  { true || : } &&
  echo everything ok

except that because it is shell you have to add an extra semicolon after
the ":". ;)

Syntax-complaints aside, I think it is a very easy thing for
contributors to get wrong. So I think test_might_fail has value, though
I do not care if it has a different name.

-Peff