ATO 678 missing slot set event on a custom action filled slot

changelog/12314.bugfix.md

@@ -0,0 +1,22 @@
+`SlotSet` events will be emitted when the value set by the custom action is the same as the existing value of the slot. This was fixed for `AugmentedMemoizationPolicy` to work properly with truncated trackers.
+
+To restore the previous behaviour, the custom action can return a SlotSet only if the slot value has changed. For example,
+
+```
+class CustomAction(Action):
+    def name(self) -> Text:
+        return "custom_action"
+
+    def run(self, dispatcher: CollectingDispatcher,
+            tracker: Tracker,
+            domain: Dict[Text, Any]) -> List[Dict[Text, Any]]:
+        # current value of the slot
+        slot_value = tracker.get_slot('my_slot')
+
+        # value of the entity
+        # this is parsed from the user utterance
+        entity_value = next(tracker.get_latest_entity_values("entity_name"), None)
+
+        if slot_value != entity_value:
+          return[SlotSet("my_slot", entity_value)]
+```

rasa/core/actions/action.py

@@ -153,7 +153,6 @@ def is_retrieval_action(action_name: Text, retrieval_intents: List[Text]) -> boo
         `True` if the resolved intent name is present in the list of retrieval
         intents, `False` otherwise.
     """
-
     return (
         ActionRetrieveResponse.intent_name_from_action(action_name) in retrieval_intents
     )
@@ -210,7 +209,6 @@ def action_for_name_or_text(
 
 def create_bot_utterance(message: Dict[Text, Any]) -> BotUttered:
     """Create BotUttered event from message."""
-
     bot_message = BotUttered(
         text=message.pop("text", None),
         data={
@@ -236,7 +234,6 @@ class Action:
 
     def name(self) -> Text:
         """Unique identifier of this simple action."""
-
         raise NotImplementedError
 
     async def run(
@@ -508,7 +505,8 @@ class ActionListen(Action):
     """The first action in any turn - bot waits for a user message.
 
     The bot should stop taking further actions and wait for the user to say
-    something."""
+    something.
+    """
 
     def name(self) -> Text:
         return ACTION_LISTEN_NAME
@@ -568,7 +566,6 @@ def _slot_set_events_from_tracker(
         tracker: "DialogueStateTracker",
     ) -> List["SlotSet"]:
         """Fetch SlotSet events from tracker and carry over key, value and metadata."""
-
         return [
             SlotSet(key=event.key, value=event.value, metadata=event.metadata)
             for event in tracker.applied_events()
@@ -830,7 +827,8 @@ def name(self) -> Text:
 
 class ActionExecutionRejection(RasaException):
     """Raising this exception will allow other policies
-    to predict a different action"""
+    to predict a different action.
+    """
 
     def __init__(self, action_name: Text, message: Optional[Text] = None) -> None:
         self.action_name = action_name
@@ -1098,8 +1096,7 @@ async def _run_custom_action(
             )
             for event in custom_events:
                 if isinstance(event, SlotSet):
-                    if tracker.get_slot(event.key) != event.value:
-                        slot_events.append(event)
+                    slot_events.append(event)
                 elif isinstance(event, BotUttered):
                     slot_events.append(event)
                 else:

tests/core/test_actions.py

@@ -2509,7 +2509,7 @@ async def test_action_extract_slots_with_none_value_custom_mapping():
             tracker,
             domain,
         )
-        assert events == []
+        assert events == [SlotSet("custom_slot", None)]
 
 
 async def test_action_extract_slots_returns_bot_uttered():
@@ -2825,3 +2825,61 @@ async def test_action_extract_slots_priority_of_slot_mappings():
     )
     tracker.update_with_events(events, domain=domain)
     assert tracker.get_slot("location_slot") == entity_value
+
+
+async def test_action_extract_slots_allows_slotset_for_same_value(
+    caplog: LogCaptureFixture,
+):
+    domain_yaml = textwrap.dedent(
+        f"""
+        version: "{LATEST_TRAINING_DATA_FORMAT_VERSION}"
+
+        slots:
+          custom_slot_a:
+            type: text
+            influence_conversation: false
+            mappings:
+            - type: custom
+              action: custom_extract_action
+
+        actions:
+        - custom_extract_action
+        - action_validate_slot_mappings
+        """
+    )
+    domain = Domain.from_yaml(domain_yaml)
+    event = UserUttered("Hi")
+    tracker = DialogueStateTracker.from_events(
+        sender_id="test_id", evts=[event], slots=domain.slots
+    )
+
+    # Set the value of the slot in the tracker manually
+    tracker.update(SlotSet("custom_slot_a", "test_A"))
+    action_server_url = "https://my-action-server:5055/webhook"
+
+    with aioresponses() as mocked:
+        mocked.post(
+            action_server_url,
+            payload={
+                "events": [
+                    {"event": "slot", "name": "custom_slot_a", "value": "test_A"}
+                ]
+            },
+        )
+
+        action_server = EndpointConfig(action_server_url)
+        action_extract_slots = ActionExtractSlots(action_server)
+
+        with caplog.at_level(logging.INFO):
+            events = await action_extract_slots.run(
+                CollectingOutputChannel(),
+                TemplatedNaturalLanguageGenerator(domain.responses),
+                tracker,
+                domain,
+            )
+
+        caplog_info_records = list(
+            filter(lambda x: x[1] == logging.INFO, caplog.record_tuples)
+        )
+        assert len(caplog_info_records) == 0
+        assert events == [SlotSet("custom_slot_a", "test_A")]