Subject: Re: [PATCH v2 3/7] read-tree: expand sparse checkout test coverage

From: Victoria Dye <[email-masked]>
Date: Mon, 28 Feb 2022 10:14:53 -0800

Elijah Newren wrote:
> On Thu, Feb 24, 2022 at 2:34 PM Victoria Dye via GitGitGadget
> <[email-masked]> wrote:
>>
>> From: Victoria Dye <[email-masked]>
>>
>> Add tests focused on how 'git read-tree' behaves in sparse checkouts. Extra
>> emphasis is placed on interactions with files outside the sparse cone, e.g.
>> merges with out-of-cone conflicts.
>>
>> Signed-off-by: Victoria Dye <[email-masked]>
>> ---
>>  t/perf/p2000-sparse-operations.sh        |  1 +
>>  t/t1092-sparse-checkout-compatibility.sh | 85 ++++++++++++++++++++++++
>>  2 files changed, 86 insertions(+)
>>
>> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
>> index 2a7106b9495..382716cfca9 100755
>> --- a/t/perf/p2000-sparse-operations.sh
>> +++ b/t/perf/p2000-sparse-operations.sh
>> @@ -117,6 +117,7 @@ test_perf_on_all git diff
>>  test_perf_on_all git diff --cached
>>  test_perf_on_all git blame $SPARSE_CONE/a
>>  test_perf_on_all git blame $SPARSE_CONE/f3/a
>> +test_perf_on_all git read-tree -mu HEAD
>>  test_perf_on_all git checkout-index -f --all
>>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>>
>> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
>> index b1dcaa0e642..9d58da4e925 100755
>> --- a/t/t1092-sparse-checkout-compatibility.sh
>> +++ b/t/t1092-sparse-checkout-compatibility.sh
>> @@ -819,6 +819,91 @@ test_expect_success 'update-index --cacheinfo' '
>>         test_cmp expect sparse-checkout-out
>>  '
>>
>> +test_expect_success 'read-tree --merge with files outside sparse definition' '
>> +       init_repos &&
>> +
>> +       test_all_match git checkout -b test-branch update-folder1 &&
>> +       for MERGE_TREES in "base HEAD update-folder2" \
>> +                          "update-folder1 update-folder2" \
>> +                          "update-folder2"
>> +       do
>> +               # Clean up and remove on-disk files
>> +               test_all_match git reset --hard HEAD &&
>> +               test_sparse_match git sparse-checkout reapply &&
>> +
>> +               # Although the index matches, without --no-sparse-checkout, outside-of-
>> +               # definition files will not exist on disk for sparse checkouts
>> +               test_all_match git read-tree -mu $MERGE_TREES &&
>> +               test_all_match git status --porcelain=v2 &&
>> +               test_path_is_missing sparse-checkout/folder2 &&
>> +               test_path_is_missing sparse-index/folder2 &&
>> +
>> +               test_all_match git read-tree --reset -u HEAD &&
>> +               test_all_match git status --porcelain=v2 &&
>> +
>> +               test_all_match git read-tree -mu --no-sparse-checkout $MERGE_TREES &&
>> +               test_all_match git status --porcelain=v2 &&
>> +               test_cmp sparse-checkout/folder2/a sparse-index/folder2/a &&
>> +               test_cmp sparse-checkout/folder2/a full-checkout/folder2/a || return 1
>> +       done
>> +'
>> +
>> +test_expect_success 'read-tree --merge with edit/edit conflicts in sparse directories' '
>> +       init_repos &&
>> +
>> +       # Merge of multiple changes to same directory (but not same files) should
>> +       # succeed
>> +       test_all_match git read-tree -mu base rename-base update-folder1 &&
>> +       test_all_match git status --porcelain=v2 &&
>> +
>> +       test_all_match git reset --hard &&
>> +
>> +       test_all_match git read-tree -mu rename-base update-folder2 &&
>> +       test_all_match git status --porcelain=v2 &&
>> +
>> +       test_all_match git reset --hard &&
>> +
>> +       test_all_match test_must_fail git read-tree -mu base update-folder1 rename-out-to-in &&
>> +       test_all_match test_must_fail git read-tree -mu rename-out-to-in update-folder1
>> +'
>> +
>> +test_expect_success 'read-tree --prefix outside sparse definition' '
>> +       init_repos &&
>> +
>> +       # Cannot read-tree --prefix with a single argument when files exist within
>> +       # prefix
> 
> Given the comments in the cover letter about --prefix needing special
> work, it's not clear to me whether the below is expected behavior or
> current-but-buggy behavior that you are testing and documenting.
> Could you clarify?
> 

It's expected - per 'Documentation/git-read-tree.txt':

	The command will refuse to overwrite entries that already
	existed in the original index file.

I'll update the comment to make that clearer. Thanks!

>> +       test_all_match test_must_fail git read-tree --prefix=folder1/ -u update-folder1 &&
>> +
>> +       test_all_match git read-tree --prefix=folder2/0 -u rename-base &&
>> +       test_path_is_missing sparse-checkout/folder2 &&
>> +       test_path_is_missing sparse-index/folder2 &&
>> +
>> +       test_all_match git read-tree --reset -u HEAD &&
>> +       test_all_match git read-tree --prefix=folder2/0 -u --no-sparse-checkout rename-base &&
>> +       test_cmp sparse-checkout/folder2/0/a sparse-index/folder2/0/a &&
>> +       test_cmp sparse-checkout/folder2/0/a full-checkout/folder2/0/a
>> +'
>> +
>> +test_expect_success 'read-tree --merge with directory-file conflicts' '
>> +       init_repos &&
>> +
>> +       test_all_match git checkout -b test-branch rename-base &&
>> +
>> +       # Although the index matches, without --no-sparse-checkout, outside-of-
>> +       # definition files will not exist on disk for sparse checkouts
>> +       test_sparse_match git read-tree -mu rename-out-to-out &&
>> +       test_sparse_match git status --porcelain=v2 &&
>> +       test_path_is_missing sparse-checkout/folder2 &&
>> +       test_path_is_missing sparse-index/folder2 &&
>> +
>> +       test_sparse_match git read-tree --reset -u HEAD &&
>> +       test_sparse_match git status --porcelain=v2 &&
>> +
>> +       test_sparse_match git read-tree -mu --no-sparse-checkout rename-out-to-out &&
>> +       test_sparse_match git status --porcelain=v2 &&
>> +       test_cmp sparse-checkout/folder2/0/1 sparse-index/folder2/0/1
>> +'
>> +
>>  test_expect_success 'merge, cherry-pick, and rebase' '
>>         init_repos &&
>>
>> --
>> gitgitgadget
>>