Subject: [PATCH v10 1/2] t1092: add tests for `git diff-files`

From: Shuqi Liang <[email-masked]>
Date: Wed, 3 May 2023 17:55:48 -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. 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 | 39 ++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 0c784813f1..eddae7ee08 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -2108,4 +2108,43 @@ test_expect_success 'sparse-index is not expanded: write-tree' '
 	ensure_not_expanded write-tree
 '
 
+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_success 'diff-files with pathspec outside sparse definition' '
+	init_repos &&
+
+	test_sparse_match 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 -p folder1 &&
+	run_on_all cp a 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_all_match git diff-files "folder*/a"
+'
+
 test_done
-- 
2.39.0