Merge pull request #339 from RasaHQ/7078/intent_from_fallback_helper

7078/intent_from_fallback_helper

changelog/7078.improvement.md

@@ -0,0 +1,2 @@
+Adds the method `get_intent_of_latest_message` to the `Tracker` allowing easier 
+access to the user's latest intent in case of an `nlu_fallback`. 

docs/docs/sdk-tracker.mdx

@@ -119,3 +119,21 @@ Return a list of events after the most recent restart.
   * **Return type**
 
   `Optional[Any]`
+
+### Tracker.get_intent_of_latest_message
+
+  Retrieves the user's latest intent.
+
+  * **Parameters**
+
+    * `skip_fallback_intent` (default: `True`) – Optionally skip the `nlu_fallback` intent and return the next highest ranked.
+
+
+  * **Returns**
+
+  The intent of the latest message if available.
+
+
+  * **Return type**
+
+  `Optional[Text]`

rasa_sdk/interfaces.py

@@ -13,6 +13,7 @@
 logger = logging.getLogger(__name__)
 
 ACTION_LISTEN_NAME = "action_listen"
+NLU_FALLBACK_INTENT_NAME = "nlu_fallback"
 
 
 class Tracker:
@@ -271,6 +272,38 @@ def add_slots(self, slots: List[EventType]) -> None:
             self.slots[event["name"]] = event["value"]
             self.events.append(event)
 
+    def get_intent_of_latest_message(
+        self, skip_fallback_intent: bool = True
+    ) -> Optional[Text]:
+        """Retrieves the intent the last user message.
+
+        Args:
+            skip_fallback_intent: Optionally skip the nlu_fallback intent
+                and return the next.
+
+        Returns:
+            Intent of latest message if available.
+        """
+        latest_message = self.latest_message
+        if not latest_message:
+            return None
+
+        intent_ranking = latest_message.get("intent_ranking")
+        if not intent_ranking:
+            return None
+
+        highest_ranking_intent = intent_ranking[0]
+        if (
+            highest_ranking_intent["name"] == NLU_FALLBACK_INTENT_NAME
+            and skip_fallback_intent
+        ):
+            if len(intent_ranking) >= 2:
+                return intent_ranking[1]["name"]
+            else:
+                return None
+        else:
+            return highest_ranking_intent["name"]
+
 
 class Action:
     """Next action to be taken in response to a dialogue state."""

tests/test_tracker.py

@@ -4,11 +4,10 @@
 from rasa_sdk.events import (
     ActionExecuted,
     UserUttered,
-    ActionReverted,
     SlotSet,
     Restarted,
 )
-from rasa_sdk.interfaces import ACTION_LISTEN_NAME
+from rasa_sdk.interfaces import ACTION_LISTEN_NAME, NLU_FALLBACK_INTENT_NAME
 from typing import List, Dict, Text, Any
 
 
@@ -133,3 +132,45 @@ def test_get_extracted_slots_with_no_active_loop():
         "some_other": "some_value2",
         "my_slot": "some_value",
     }
+
+
+def test_get_intent_of_latest_message_with_missing_data():
+    tracker = get_tracker([])
+
+    tracker.latest_message = None
+    assert not tracker.get_intent_of_latest_message()
+
+    tracker.latest_message = {
+        "intent": {"name": NLU_FALLBACK_INTENT_NAME, "confidence": 0.9},
+    }
+    assert not tracker.get_intent_of_latest_message()
+
+
+def test_get_intent_of_latest_message_with_only_fallback():
+    tracker = get_tracker([])
+    tracker.latest_message = {
+        "intent": {"name": NLU_FALLBACK_INTENT_NAME, "confidence": 0.9},
+        "intent_ranking": [{"name": NLU_FALLBACK_INTENT_NAME, "confidence": 0.9}],
+    }
+    assert not tracker.get_intent_of_latest_message()
+    assert (
+        tracker.get_intent_of_latest_message(skip_fallback_intent=False)
+        == NLU_FALLBACK_INTENT_NAME
+    )
+
+
+def test_get_intent_of_latest_message_with_user_intent():
+    tracker = get_tracker([])
+    tracker.latest_message = {
+        "intent": {"name": NLU_FALLBACK_INTENT_NAME, "confidence": 0.9},
+        "intent_ranking": [
+            {"name": NLU_FALLBACK_INTENT_NAME, "confidence": 0.9},
+            {"name": "hello", "confidence": 0.8},
+            {"name": "goodbye", "confidence": 0.7},
+        ],
+    }
+    assert tracker.get_intent_of_latest_message() == "hello"
+    assert (
+        tracker.get_intent_of_latest_message(skip_fallback_intent=False)
+        == NLU_FALLBACK_INTENT_NAME
+    )