Re: [PATCH] archive: add test testing MIME for created archive through compression filter

From: Jeff King <peff@peff.net>
Date: Oct 11, 2021, 16:07 UTC
Message-ID: <YWRhR9IXZfU93Uok@coredump.intra.peff.net>
In-Reply-To: <xmqqlf2zd0d4.fsf@gitster.g>

On Mon, Oct 11, 2021 at 08:53:11AM -0700, Junio C Hamano wrote:

Show 18 quoted lines

> Bagas Sanjaya <bagasdotme@gmail.com> writes:
> 
> > +test_expect_success GZIP,BZIP2,XZ 'git archive with gzip, bzip2, and xz filters creates compressed tar archive with proper MIME type' '
> > +	git config tar.tar.bz2.command "bzip2 -c" &&
> > +	git config tar.tar.xz.command "xz -c" &&
> > +	git archive --output HEAD.tar.gz --prefix=src/ HEAD &&
> 
> I think a lot more portable and robust way to test the feature is to
> configure git config tar.tar.test.command (or come up with a name for
> a suffix to be used in the test), point it at a script created in this
> test script and run git archive with output filename that would trigger
> the command.  Then, arrange the test to notice if the "test" script was
> called with expected command line arguments and standard input.
> 
> That way, you do not need to rely on prereqs and you do not have to
> resort to un-portable use of the "file" command.  After all, you are
> *not* testing if "bzip2 -c" the user happens to have on their $PATH
> produces output their "find" recognises as bzip2 compressed.

That would work. Or perhaps using something portable like "tr" to do a nonsense conversion, and verifying that we can get convert back to the original. Like say, the tests added to t5000 by 767cf4579f (archive: implement configurable tar filters, 2011-06-21).

I don't think the newly proposed test is adding anything beyond that (except checking the system "bzip2" command, but as you say, that is not useful to us, nor portable).

-Peff