test-common.sh: add an empty() routine to check if a file is empty, use it

1 files changed, 5 insertions, 5 deletions

diff --git a/test/librestage-test.sh b/test/librestage-test.sh
index 849a68c..5c7487b 100644
--- a/test/librestage-test.sh
+++ b/test/librestage-test.sh
@@ -26,23 +26,23 @@ it_displays_usage_text() {
 	LANG=C librestage -h >$tmpdir/stdout 2>$tmpdir/stderr
 
 	[[ "$(sed 1q "$tmpdir/stdout")" =~ Usage:.* ]]
-	[[ -z "$(cat "$tmpdir/stderr")" ]]
+	empty "$tmpdir/stderr"
 }
 
 it_fails_with_0_args() {
 	librestage >$tmpdir/stdout 2>$tmpdir/stderr || stat=$?
 
 	[[ $stat != 0 ]]
-	[[ -z "$(cat "$tmpdir/stdout")" ]]
-	[[ -n "$(cat "$tmpdir/stderr")" ]]
+	empty "$tmpdir/stdout"
+	! empty "$tmpdir/stderr"
 }
 
 it_fails_with_invalid_args() {
 	librestage -q >$tmpdir/stdout 2>$tmpdir/stderr || stat=$?
 
 	[[ $stat != 0 ]]
-	[[ -z "$(cat "$tmpdir/stdout")" ]]
-	[[ -n "$(cat "$tmpdir/stderr")" ]]
+	empty "$tmpdir/stdout"
+	! empty "$tmpdir/stderr"
 }
 
 # This was an actual bug I hit with md/emacs-mdmua a long time ago; solution was