On Wed, Mar 27 2019, SZEDER Gábor wrote:

On Wed, Mar 27, 2019 at 12:21:55PM +0100, Ævar Arnfjörð Bjarmason wrote:

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On Wed, Mar 27 2019, SZEDER Gábor wrote:

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On Wed, Mar 27, 2019 at 11:09:18AM +0100, Ævar Arnfjörð Bjarmason wrote:

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There are likewise several that use one of
   ! test -e path/to/filename
or
   ! test -f path/to/filename
or
  test ! -f path/to/filename
which could be replaced by
  test_path_is_missing path/to/filename

Interesting that for some we use the 'test_is_there/test_is_not_there'
pattern and for others 'test_is_there [!]'. E.g
test_path_exist/test_path_is_missing v.s. test_i18ngrep.

It's unclear what the '!' should negate in case of 'test_path_is_file
! file'.  What if 'file' does exists, but it's not a file but a
directory, socket, fifo, or symlink?  'test ! -f file' returns success
in these cases as well.

OTOH, it's quite clear what the negation should mean in case of
'test_i18ngrep'.

*Should* we make it better? Yeah sure, maybe. I'm just pointing out for
context to someone poking at this for the first time that now we
sometimes do "! foo <arg>" v.s. "foo <arg>" as "foo_is <arg>" and
"foo_not <arg>" and other times "foo [!] <arg>".

So yeah, maybe we should improve things to disambiguate the cases you
mentioned, but right now e.g. "test_path_exists" and
"test_path_is_missing" are just "test -e" and "! test -e", respectively.

I'm not sure why 'test_path_exists' exists, as I don't readily see a
valid reason why a test should only be interested in whether the path
exists, but but not whether it's a file or a directory.

In the general case the same reason we use "test -e". While the test
would pass in all sorts of unexpected cases, those probably aren't
plausible and we're just e.g. checking "did the thing create a file
it'll create in XYZ mode?"....

Luckily it
haven't caught on, and it's only used twice in the whole test suite.

Well, we have some >100 "test -e" though ... :)

However, as shown above, the existend of 'test_path_is_missing' is
very much justified.

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The same caveats you've mentioned also apply to "test_i18ngrep" b.t.w.,
there we squash the 3x standard exit codes of grep[1] into a boolean,
and thus e.g. ignore the difference between <file> not matching an
<file> being a directory or whatever.

I'm not sure I understand, 'test_i18ngrep' handles the missing file or
not a file cases reasonably well:

  expecting success:
          test_i18ngrep ! foo nonexistent-file

  error: bug in the test script: test_i18ngrep requires a file to read as the last parameter

or

  expecting success:
          mkdir dir &&
          test_i18ngrep ! foo dir

  error: bug in the test script: test_i18ngrep requires a file to read as the last parameter

Yeah you're right, I didn't read it carefully enough and it does handle
*that* particular case, but e.g. a grep of "file" where we can't read it
due to a permission error is the same as "didn't contain the string".

I'm not saying that's a bad thing, but the opposite. We assume a certain
base level of sanity, e.g. we do "test_must_fail <cmd>" only for git,
but "! <cmd>" for everything else, even though e.g. the system "grep"
may be segfaulting.

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1. http://pubs.opengroup.org/onlinepubs/009695399/utilities/grep.html