Re: [PATCH v4 4/9] t3701: don't hard code sha1 hash values

> SZEDER Gábor <szeder.dev@gmail.com> writes:
> 
>>> +diff_cmp () {
>>> +	for x
>>> +	do
>>> +		sed  -e '/^index/s/[0-9a-f]*[1-9a-f][0-9a-f]*\.\./1234567../' \
>>> +		     -e '/^index/s/\.\.[0-9a-f]*[1-9a-f][0-9a-f]*/..9abcdef/' \
>>> +		     -e '/^index/s/ 00*\.\./ 0000000../' \
>>> +		     -e '/^index/s/\.\.00*$/..0000000/' \
>>> +		     -e '/^index/s/\.\.00* /..0000000 /' \
>>> +		     "$x" >"$x.filtered"
>>> +	done
>>> +	test_cmp "$1.filtered" "$2.filtered"
>>> +}
>>
>> t3701 is not the only test script comparing diffs, many other
>> tests do so:
>>
>>   $ git grep 'diff --git' t/ |wc -l
>>   835
>>
>> It's totally inaccurate, but a good ballpark figure.
>>
>> I think this function should be a widely available test helper
>> function in 'test-lib-functions.sh', perhaps renamed to
>> 'test_cmp_diff', so those other tests could use it as well.
> 
> I am on the fence.  
> 
> The above does not redact enough (e.g. rename/copy score should be
> redacted while comparing) to serve as a generic filter.
> 
> We could certainly extend it when we make code in other tests use
> the helper, but then we can do the moving to test-lib-functions when
> that happens, too.
> 
> Those who will be writing new tests that need to compare two diff
> outputs are either (1) people who are careful and try to find
> existing tests that do the same, to locate the helper we already
> have to be reused in theirs, or (2) people who don't and roll their
> own.  The latter camp cannot be helped either way, but the former
> will run "git grep 'diff --git' t/" and find the helper whether it
> is in this script or in test-lib-functions, I would think.
> 
> So, I certainly do not mind a reroll to move it to a more generic
> place, but I do not think I would terribly mind if we leave it in
> its current place, later to be moved by the first new caller that
> wants to use it from outside this script.
>