fix(actions): don't run empty Lua scripts (#22084) (cherry-pick #22161) (#22172)

Signed-off-by: Michael Crenshaw <[email protected]>
Co-authored-by: Michael Crenshaw <[email protected]>

Author: gcp-cherry-pick-bot[bot]

util/lua/lua.go

@@ -398,10 +398,12 @@ func (vm VM) GetResourceActionDiscovery(obj *unstructured.Unstructured) ([]strin
 	// Fetch predefined Lua scripts
 	discoveryKey := fmt.Sprintf("%s/actions/", key)
 	discoveryScript, err := vm.getPredefinedLuaScripts(discoveryKey, actionDiscoveryScriptFile)
-
-	// Ignore the error if the script does not exist.
-	var doesNotExistErr *ScriptDoesNotExistError
-	if err != nil && !errors.As(err, &doesNotExistErr) {
+	if err != nil {
+		var doesNotExistErr *ScriptDoesNotExistError
+		if errors.As(err, &doesNotExistErr) {
+			// No worries, just return what we have.
+			return discoveryScripts, nil
+		}
 		return nil, fmt.Errorf("error while fetching predefined lua scripts: %w", err)
 	}
 

util/lua/lua_test.go

@@ -325,7 +325,7 @@ func TestGetResourceActionDiscoveryNoPredefined(t *testing.T) {
 	vm := VM{}
 	discoveryLua, err := vm.GetResourceActionDiscovery(testObj)
 	require.NoError(t, err)
-	assert.Equal(t, "", discoveryLua[0])
+	assert.Empty(t, discoveryLua)
 }
 
 func TestGetResourceActionDiscoveryWithOverride(t *testing.T) {