Re: [RFC/PATCH 3/5] ls-files: add and use a new --sparse option

On 3/17/2021 9:28 AM, Ævar Arnfjörð Bjarmason wrote:

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh

I want to learn from your suggested changes to the test, here,
so forgive my questions here:
  

+test_index_entry_like () {
+	dir=$1
+	shift
+	fmt=$1
+	shift
+	rev=$1
+	shift
+	entry=$1
+	shift
+	file=$1
+	shift

Why all the shifts? Why not just use $1, $2, $3,...? My
guess is that you want to be able to insert a new parameter
in the middle in the future without changing the later
numbers, but that seems unlikely, and we could just add
the parameter at the end.

+	hash=$(git -C "$dir" rev-parse "$rev") &&
+	printf "$fmt\n" "$hash" "$entry" >expected &&
+	if grep "$entry" "$file" >line
+	then
+		test_cmp expected line
+	else
+		cat cache &&
+		false
+	fi
+}
+
 test_expect_success 'sparse-index contents' '
 	init_repos &&
 
-	test-tool -C sparse-index read-cache --table >cache &&
+	git -C sparse-index ls-files --sparse >cache &&
 	for dir in folder1 folder2 x
 	do
-		TREE=$(git -C sparse-index rev-parse HEAD:$dir) &&
-		grep "040000 tree $TREE	$dir/" cache \
-			|| return 1
+		test_index_entry_like sparse-index "040000 %s 0\t%s" "HEAD:$dir" "$dir/" cache || return 1

I see how this uses only one line, but it seems like the
test_index_entry_like is too generic to make it not a
complicated mess of format strings that need to copy
over and over again.

Perhaps instead it could be a "test_entry_is_tree"
and it only passes "$dir" and "cache"? Then we could drop the loop and
just have

	test_entry_is_tree cache folder1 &&
	test_entry_is_tree cache folder2 &&
	test_entry_is_tree cache x &&

or we could still use the loop, especially when we test for four trees.

-	test-tool -C sparse-index read-cache --table >cache &&
+	git -C sparse-index ls-files --sparse >cache &&
 	for dir in deep/deeper2 folder1 folder2 x
 	do
-		TREE=$(git -C sparse-index rev-parse HEAD:$dir) &&
-		grep "040000 tree $TREE	$dir/" cache \
-			|| return 1
+		test_index_entry_like sparse-index "040000 %s 0\t%s" "HEAD:$dir" "$dir/" cache || return 1
 	done &&
 
+	grep 040000 cache >lines &&
+	test_line_count = 4 lines &&
+

The point here is to check that no other entries are trees? We know
that this number will be _at least_ 4 based on the loop above.

Thanks,
-Stolee