Subject: [PATCH v6 1/2] t1092: add tests for `git diff-files`

From: Shuqi Liang <[email-masked]>
Date: Mon, 20 Mar 2023 16:52:40 -0400

Before integrating the 'git diff-files' builtin
with the sparse index feature, add tests to
t1092-sparse-checkout-compatibility.sh to ensure it currently works
with sparse-checkout and will still work with sparse index
after that integration.

When adding tests against a sparse-checkout
definition, we test two modes: all changes are
within the sparse-checkout cone and some changes are outside
the sparse-checkout cone.

In order to have staged changes outside of
the sparse-checkout cone, make a directory called 'folder1' and
copy `a` into 'folder1/a'. 'folder1/a' is identical to `a` in the base
commit. These make 'folder1/a' in the index, while leaving it outside of
the sparse-checkout definition. Test 'folder1/a'being present on-disk
without modifications, then change content inside 'folder1/a' in order
to test 'folder1/a' being present on-disk with modifications.

Signed-off-by: Shuqi Liang <[email-masked]>
---
 t/t1092-sparse-checkout-compatibility.sh | 42 ++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..c1329e2f16 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -2055,4 +2055,46 @@ test_expect_success 'grep sparse directory within submodules' '
 	test_cmp actual expect
 '
 
+test_expect_success 'diff-files with pathspec inside sparse definition' '
+	init_repos &&
+
+	write_script edit-contents <<-\EOF &&
+	echo text >>"$1"
+	EOF
+
+	run_on_all ../edit-contents deep/a &&
+
+	test_all_match git diff-files &&
+
+	test_all_match git diff-files deep/a && 
+
+	# test wildcard
+	test_all_match git diff-files deep/*
+'
+
+test_expect_failure 'diff-files with pathspec outside sparse definition' '
+	init_repos &&
+
+	test_sparse_match test_must_fail git diff-files folder2/a &&
+
+	write_script edit-contents <<-\EOF &&
+	echo text >>"$1"
+	EOF
+
+	# Add file to the index but outside of cone for sparse-checkout cases.
+	# Add file to the index without sparse-checkout cases to ensure all have 
+	# same output.
+	run_on_all mkdir folder1 &&
+	run_on_all cp a folder1/a &&
+
+	# file present on-disk without modifications
+	test_all_match git diff-files &&
+	test_all_match git diff-files folder1/a &&
+
+	# file present on-disk with modifications
+	run_on_all ../edit-contents folder1/a &&
+	test_all_match git diff-files &&
+	test_all_match git diff-files folder1/a
+'
+
 test_done
-- 
2.39.0