Re: [PATCH v2 1/2] t7700: check post-condition in kept-pack test

[Derrick Stolee <derrickstolee@github.com>]

On 3/25/2022 1:07 PM, Junio C Hamano wrote:
> "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> +get_sorted_objects_from_packs () {
>> +	git show-index <$(cat) >raw &&
>> +	cut -d" " -f2 raw | sort
>> +}
> 
> As pointed out by Taylor, this "the standard input gives us the name
> of a file to be read" looks strange.  It may work, and it may even
> give the easiest interface to use by all the callers, but if we were
> designing a more generic helper function suitable to be added to the
> test-lib*.sh, we wouldn't design it like so---instead it would be
> either "we read the contents of the .idx file from the standard
> input" or "the first argument is the name of the .idx file".

Ok. Can do.
 
>>  test_expect_success '--write-midx -b packs non-kept objects' '
>> +	git init repo &&
>> +	test_when_finished "rm -fr repo" &&
>> +	(
>> +		cd repo &&
>> +
>> +		# Create a kept pack-file
>> +		test_commit base &&
>> +		git repack -ad &&
>> +		find $objdir/pack -name "*.idx" >before &&
>> +		>$objdir/pack/$(basename $(cat before) .idx).keep &&
> 
> We probably want to sanity check "repack -a" by insisting "before"
> has found exactly one .idx file, before using it this way.

> 		test_line_count = 1 before &&
> 		before=$(cat before) &&
> 		>"${before%.idx}.keep"

Good idea. This mixture of a file and variable sharing
a name is a bit muddy for me, though. Using "before_name"
as the variable would be enough of a differentiator.

>> +		find $objdir/pack -name "*.keep" >kept &&
>> +		test_line_count = 1 kept &&
> 
> Since we've made sure "before" is a one-liner earlier, we could just
> say
 
> 		test_cmp before kept &&
> 
> instead, no?

'before' contains a .idx name and 'kept' contains a .keep name,
so this direct comparison does not work. We could do that
additional check like this:

	kept_name=$(cat kept) &&
	echo ${kept_name%.keep}.idx >kept-idx &&
	test_cmp before kept-idx &&

Thanks for taking the time to clean this up, as it might become
a good example for these kinds of post-condition checks of the packs
directory in the future.

Thanks,
-Stolee