t0020: use modern test_* helpers

diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh
index 2ab3c487340569d7f2f8164776907ef30df2d415..075ece6db16f9c313504559d95c5b1dc6b4c2e07 100755 (executable)
--- a/t/t4053-diff-no-index.sh
+++ b/t/t4053-diff-no-index.sh
@@ -17,8 +17,8 @@ test_expect_success 'setup' '
 '
 
 test_expect_success 'git diff --no-index directories' '
-       git diff --no-index a b >cnt
-       test $? = 1 && test_line_count = 14 cnt
+       test_expect_code 1 git diff --no-index a b >cnt &&
+       test_line_count = 14 cnt
 '
 
 test_expect_success 'git diff --no-index relative path outside repo' '