wrap up and tests for flow trigger action

rasa/core/actions/action.py

@@ -225,9 +225,9 @@ def action_for_name_or_text(
         return FormAction(action_name_or_text, action_endpoint)
 
     if action_name_or_text.startswith(FLOW_PREFIX):
-        from rasa.core.actions.flows import FlowTriggerAction
+        from rasa.core.actions.action_trigger_flow import ActionTriggerFlow
 
-        return FlowTriggerAction(action_name_or_text)
+        return ActionTriggerFlow(action_name_or_text)
     return RemoteAction(action_name_or_text, action_endpoint)
 
 

rasa/core/actions/flow_trigger_action.py → rasa/core/actions/action_trigger_flow.py

@@ -22,54 +22,81 @@
 structlogger = structlog.get_logger(__name__)
 
 
-class FlowTriggerAction(action.Action):
-    """Action which implements and executes the form logic."""
+class ActionTriggerFlow(action.Action):
+    """Action which triggers a flow by putting it on the dialogue stack."""
 
     def __init__(self, flow_action_name: Text) -> None:
-        """Creates a `FlowTriggerAction`.
+        """Creates a `ActionTriggerFlow`.
 
         Args:
             flow_action_name: Name of the flow.
         """
         super().__init__()
+
+        if not flow_action_name.startswith(FLOW_PREFIX):
+            raise ValueError(
+                f"Flow action name '{flow_action_name}' needs to start with "
+                f"'{FLOW_PREFIX}'."
+            )
+
         self._flow_name = flow_action_name[len(FLOW_PREFIX) :]
         self._flow_action_name = flow_action_name
 
     def name(self) -> Text:
         """Return the flow name."""
         return self._flow_action_name
 
-    async def run(
-        self,
-        output_channel: "OutputChannel",
-        nlg: "NaturalLanguageGenerator",
-        tracker: "DialogueStateTracker",
-        domain: "Domain",
-        metadata: Optional[Dict[Text, Any]] = None,
-    ) -> List[Event]:
-        """Trigger the flow."""
+    def create_event_to_start_flow(self, tracker: DialogueStateTracker) -> Event:
+        """Create an event to start the flow.
+
+        Args:
+            tracker: The tracker to start the flow on.
+
+        Returns:
+            The event to start the flow."""
         stack = DialogueStack.from_tracker(tracker)
-        if not stack.is_empty():
-            frame_type = FlowStackFrameType.INTERRUPT
-        else:
-            frame_type = FlowStackFrameType.REGULAR
+        frame_type = (
+            FlowStackFrameType.REGULAR
+            if stack.is_empty()
+            else FlowStackFrameType.INTERRUPT
+        )
 
         stack.push(
             UserFlowStackFrame(
                 flow_id=self._flow_name,
                 frame_type=frame_type,
             )
         )
+        return stack.persist_as_event()
 
+    def create_events_to_set_flow_slots(self, metadata: Dict[str, Any]) -> List[Event]:
+        """Create events to set the flow slots.
+
+        Set additional slots to prefill information for the flow.
+
+        Args:
+            metadata: The metadata to set the slots from.
+
+        Returns:
+            The events to set the flow slots.
+        """
         slots_to_be_set = metadata.get("slots", {}) if metadata else {}
-        slot_set_events: List[Event] = [
-            SlotSet(key, value) for key, value in slots_to_be_set.items()
-        ]
+        return [SlotSet(key, value) for key, value in slots_to_be_set.items()]
+
+    async def run(
+        self,
+        output_channel: "OutputChannel",
+        nlg: "NaturalLanguageGenerator",
+        tracker: "DialogueStateTracker",
+        domain: "Domain",
+        metadata: Optional[Dict[Text, Any]] = None,
+    ) -> List[Event]:
+        """Trigger the flow."""
+        events: List[Event] = [self.create_event_to_start_flow(tracker)]
+        events.extend(self.create_events_to_set_flow_slots(metadata))
 
-        events: List[Event] = [
-            stack.persist_as_event(),
-        ] + slot_set_events
         if tracker.active_loop_name:
+            # end any active loop to ensure we are progressing the started flow
             events.append(ActiveLoop(None))
 
         return events

tests/core/actions/test_action_trigger_flow.py

@@ -0,0 +1,92 @@
+import pytest
+from rasa.core.actions.action_trigger_flow import ActionTriggerFlow
+from rasa.core.channels import CollectingOutputChannel
+from rasa.core.nlg import TemplatedNaturalLanguageGenerator
+from rasa.dialogue_understanding.stack.dialogue_stack import DialogueStack
+from rasa.dialogue_understanding.stack.frames.flow_stack_frame import (
+    FlowStackFrameType,
+    UserFlowStackFrame,
+)
+from rasa.shared.core.constants import DIALOGUE_STACK_SLOT
+from rasa.shared.core.domain import Domain
+from rasa.shared.core.events import ActiveLoop, SlotSet
+from rasa.shared.core.trackers import DialogueStateTracker
+
+
+async def test_action_trigger_flow():
+    tracker = DialogueStateTracker.from_events("test", [])
+    action = ActionTriggerFlow("flow_foo")
+    channel = CollectingOutputChannel()
+    nlg = TemplatedNaturalLanguageGenerator({})
+    events = await action.run(channel, nlg, tracker, Domain.empty())
+    assert len(events) == 1
+    event = events[0]
+    assert isinstance(event, SlotSet)
+    assert event.key == DIALOGUE_STACK_SLOT
+    assert len(event.value) == 1
+    assert event.value[0]["type"] == UserFlowStackFrame.type()
+    assert event.value[0]["flow_id"] == "foo"
+    assert event.value[0]["frame_type"] == FlowStackFrameType.REGULAR.value
+
+
+async def test_action_trigger_flow_with_slots():
+    tracker = DialogueStateTracker.from_events("test", [])
+    action = ActionTriggerFlow("flow_foo")
+    channel = CollectingOutputChannel()
+    nlg = TemplatedNaturalLanguageGenerator({})
+    events = await action.run(
+        channel, nlg, tracker, Domain.empty(), metadata={"slots": {"foo": "bar"}}
+    )
+
+    event = events[0]
+    assert isinstance(event, SlotSet)
+    assert event.key == DIALOGUE_STACK_SLOT
+    assert len(event.value) == 1
+    assert event.value[0]["type"] == UserFlowStackFrame.type()
+    assert event.value[0]["flow_id"] == "foo"
+
+    assert len(events) == 2
+    event = events[1]
+    assert isinstance(event, SlotSet)
+    assert event.key == "foo"
+    assert event.value == "bar"
+
+
+async def test_action_trigger_fails_if_name_is_invalid():
+    with pytest.raises(ValueError):
+        ActionTriggerFlow("foo")
+
+
+async def test_action_trigger_ends_an_active_loop_on_the_tracker():
+    tracker = DialogueStateTracker.from_events("test", [ActiveLoop("loop_foo")])
+    action = ActionTriggerFlow("flow_foo")
+    channel = CollectingOutputChannel()
+    nlg = TemplatedNaturalLanguageGenerator({})
+    events = await action.run(channel, nlg, tracker, Domain.empty())
+
+    assert len(events) == 2
+    assert isinstance(events[1], ActiveLoop)
+    assert events[1].name is None
+
+
+async def test_action_trigger_uses_interrupt_flow_type_if_stack_already_contains_flow():
+    user_frame = UserFlowStackFrame(
+        flow_id="my_flow", step_id="collect_bar", frame_id="some-frame-id"
+    )
+    stack = DialogueStack(frames=[user_frame])
+    tracker = DialogueStateTracker.from_events("test", [stack.persist_as_event()])
+
+    action = ActionTriggerFlow("flow_foo")
+    channel = CollectingOutputChannel()
+    nlg = TemplatedNaturalLanguageGenerator({})
+
+    events = await action.run(channel, nlg, tracker, Domain.empty())
+
+    assert len(events) == 1
+    event = events[0]
+    assert isinstance(event, SlotSet)
+    assert event.key == DIALOGUE_STACK_SLOT
+    assert len(event.value) == 2
+    assert event.value[1]["type"] == UserFlowStackFrame.type()
+    assert event.value[1]["flow_id"] == "foo"
+    assert event.value[1]["frame_type"] == FlowStackFrameType.INTERRUPT.value