From: Karthik Nayak <karthik.188@gmail.com>
Date: Wed, 19 Nov 2025 23:01:01 GMT
Subject: Re: [PATCH 2/2] refs: add GIT_REF_URI to specify reference backend and directory
Message-ID: <CAOLa=ZQvG+D7NwT1mW50pC6+QGc7_PSvoTA8GgK0cvDKondx8A@mail.gmail.com>
In-Reply-To: <CAPig+cQ1nF47Rvvm4gDks8Bzj0htzUkfR24WB8UdnJtcQTQwCA@mail.gmail.com>

Eric Sunshine <sunshine@sunshineco.com> writes:

> On Wed, Nov 19, 2025 at 4:49 PM Karthik Nayak <karthik.188@gmail.com> wrote:
>> Git allows setting a different object directory via
>> 'GIT_OBJECT_DIRECTORY', but provides no equivalent for references.
>> This asymmetry makes it difficult to test different reference backends
>> or use alternative reference storage locations without modifying the
>> repository structure.
>>
>> Add a new environment variable 'GIT_REF_URI' that specifies both the
>> reference backend and directory path using a URI format:
>> [...]
>> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
>> ---
>> diff --git a/t/t1423-ref-backend.sh b/t/t1423-ref-backend.sh
>> @@ -0,0 +1,109 @@
>> +test_expect_success 'empty uri provided' '
>> +       test_when_finished "rm -rf repo" &&
>> +       git init --ref-format=files repo &&
>> +       (
>> +               cd repo &&
>> +               GIT_REF_URI="" &&
>> +               export GIT_REF_URI &&
>> +               ! git refs list 2>err &&
>
> Should this (and all other tests) be using `test_must_fail` rather than `!`?
>

Initially I used 'BUG()' instead of 'error()', which was wrong, but
meant that I couldn't use `test_must_fail`. I've fixed that now, but
this was missed. Thanks.

>> +               test_grep "reference backend uri is empty" err
>> +       )
>> +'
>> +ref_formats="files reftable"
>> +for from_format in $ref_formats
>> +do
>> +       for to_format in $ref_formats
>> +       do
>> +               if test "$from_format" = "$to_format"
>> +               then
>> +                       continue
>> +               fi
>> +
>> +               test_expect_success 'read from other reference backend' '
>> +                       test_when_finished "rm -rf repo" &&
>> +                       git init --ref-format=files repo &&
>> +                       (
>> +                               cd repo &&
>> +                               test_commit 1 &&
>> +                               test_commit 2 &&
>> +                               test_commit 3 &&
>> +
>> +                               git refs migrate --dry-run --ref-format=reftable >out &&
>> +                               REFTABLE_PATH=$(cat out | sed "s/.* ${SQ}\(.*\)${SQ}/\1/") &&
>> +                               git refs list >expect &&
>> +                               GIT_REF_URI="reftable://$REFTABLE_PATH" git refs list >actual &&
>> +                               test_cmp expect actual
>> +                       )
>> +               '
>> +
>> +               test_expect_success 'write to other reference backend' '
>> +                       [...]
>> +               '
>> +       done
>> +done
>
> Something seems amiss here. Presumably, this nested loop wants to test
> various combinations but the `from_format` and `to_format` variables
> are never consulted in the tests; instead the tests just hardcode
> specific ref-format values.
>
> Also, if this is indeed meant to be loop-driven, then it would be
> helpful for the test titles to include the values of `$from_format`
> and `$to_format`.

Indeed. I was hasty, will fix :)