[RFC/PATCH 1/4] test-lib: add test_dir_is_empty()

For the upcoming submodule test framework we often need to assert that an
empty directory exists in the work tree. Add the test_dir_is_empty()
function which asserts that the given argument is an empty directory.

Signed-off-by: Jens Lehmann <redacted>
---

I believe this one is pretty straightforward (unless I missed that this
functionality already exists someplace I forgot to look ;-).

 t/test-lib-functions.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 158e10a..93d10cd 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh

@@ -489,6 +489,17 @@ test_path_is_dir () {
 	fi
 }

+# Check if the directory exists and is empty as expected, barf otherwise.
+test_dir_is_empty () {
+	test_path_is_dir "$1" &&
+	if test $(ls -a1 "$1" | wc -l) != 2
+	then
+		echo "Directory '$1' is not empty, it contains:"
+		ls -la "$1"
+		return 1
+	fi
+}
+
 test_path_is_missing () {
 	if [ -e "$1" ]
 	then

-- 
1.9.1.327.g3d8d896