fix: test without perl with mock_non_existing_fn

Author: Chemaclass

tests/unit/clock_test.sh

@@ -10,6 +10,10 @@ function tear_down_after_script() {
   export _OS=$__ORIGINAL_OS
 }
 
+function mock_non_existing_fn() {
+  return 127;
+}
+
 function test_now_with_perl() {
   mock perl echo "1720705883457"
 
@@ -18,22 +22,22 @@ function test_now_with_perl() {
 
 function test_now_on_linux_without_perl() {
   export _OS="Linux"
-  mock perl /dev/null
+  mock perl mock_non_existing_fn
   mock date echo "1720705883457"
 
   assert_equals "1720705883457" "$(clock::now)"
 }
 function test_now_on_windows_without_perl() {
   export _OS="Windows"
-  mock perl /dev/null
+  mock perl mock_non_existing_fn
   mock date echo "1720705883457"
 
   assert_equals "1720705883457" "$(clock::now)"
 }
 
 function test_now_on_osx_without_perl() {
   export _OS="OSX"
-  mock perl /dev/null
+  mock perl mock_non_existing_fn
 
   assert_equals "" "$(clock::now)"
 }