t0030-mount.sh: improve stdout stderr fail tests

test/sharness/lib/test-lib.sh

@@ -276,3 +276,22 @@ test_curl_resp_http_code() {
 	cat curl_output
 	return 1
 }
+
+test_must_be_empty() {
+	if test -s "$1"
+	then
+		echo "'$1' is not empty, it contains:"
+		cat "$1"
+		return 1
+	fi
+}
+
+test_should_contain() {
+	test "$#" = 2 || error "bug in the test script: not 2 parameters to test_should_contain"
+	if ! grep -q "$1" "$2"
+	then
+		echo "'$2' does not contain '$1', it contains:"
+		cat "$2"
+		return 1
+	fi
+}

test/sharness/t0030-mount.sh

@@ -20,14 +20,13 @@ test_launch_ipfs_daemon
 
 #  test mount failure before mounting properly.
 
-test_expect_success "'ipfs mount' fails when no mount dir" '
-	test_must_fail ipfs mount -f=not_ipfs -n=not_ipns >actual
+test_expect_success "'ipfs mount' fails when there is no mount dir" '
+	test_must_fail ipfs mount -f=not_ipfs -n=not_ipns >output 2>output.err
 '
 
-test_expect_success "'ipfs mount' output looks good when it fails" '
-	! grep "IPFS mounted at: $(pwd)/ipfs" actual >/dev/null &&
-	! grep "IPNS mounted at: $(pwd)/ipns" actual >/dev/null ||
-	test_fsh cat actual
+test_expect_success "'ipfs mount' output looks good" '
+	test_must_be_empty output &&
+	test_should_contain "not_ipns\|not_ipfs" output.err
 '
 
 # now mount properly, and keep going