Wrong validation method is picked inside a form (depending on the slot mapping)

Rasa Open Source
1

Hi all,

I have two slots start_date and end_date inside a form.

I have defined those slots in the expected order inside

 @staticmethod
    def required_slots(tracker: Tracker) -> List[Text]:
        return [
            "start_time",
            "end_time"
        ]

This is my slot mapping

def slot_mappings(self) -> Dict[Text, Union[Dict, List[Dict]]]:
    return {
        "start_time": [
            self.from_entity(entity="provide_date"),
            self.from_text()
        ],
        "end_time": [
            self.from_entity(entity="provide_date"),
            self.from_text()
        ]
    }

and I have following validators for each slot

 def validate_start_time(self, value: Text, dispatcher: CollectingDispatcher, tracker: Tracker,
                              domain: Dict[Text, Any], ) -> Dict[Text, Any]:
        print("Validating start time")



def validate_end_time(self, value: Text, dispatcher: CollectingDispatcher, tracker: Tracker,
                              domain: Dict[Text, Any], ) -> Dict[Text, Any]:
        print("Validating end time")

But the application selects the validate_end_time to validate the start_time slot.

But the strange thing is, if I change the slot mapping to the following, it works fine. The validators are picked as expected.

def slot_mappings(self) -> Dict[Text, Union[Dict, List[Dict]]]:
        return {
            "start_time": [
                self.from_text()
            ],
            "end_time": [
                self.from_entity(entity="provide_date"),
                self.from_text()
            ]
        }

Does the validator selection depend on slot mapping? I expected to follow the requested slot order. I appreciate your input on correcting this behavior.

Note: the requested_slot order is working as expected despite the wrong validation order