Merge pull request #427 from NVIDIA/feature/colang-single-flow-activa…

…tion

Feature/colang single flow activation

nemoguardrails/colang/v2_x/runtime/statemachine.py

@@ -473,15 +473,55 @@ def _process_internal_events_without_default_matchers(
         # Start new flow state instance if flow exists
         flow_id = event.arguments["flow_id"]
         if flow_id in state.flow_configs and flow_id != "main":
-            add_new_flow_instance(
-                state,
-                create_flow_instance(
-                    state.flow_configs[flow_id],
-                    event.arguments["flow_instance_uid"],
-                    event.arguments["flow_hierarchy_position"],
-                    event.arguments,
-                ),
-            )
+
+            started_instance = None
+            if (
+                event.arguments.get("activated", None)
+                and flow_id in state.flow_id_states
+            ):
+                # Check if there already exists an instance of the same activated flow
+                for activated_flow in state.flow_id_states[flow_id]:
+                    if activated_flow.status != FlowStatus.STARTED:
+                        continue
+                    has_same_arguments = False
+                    for idx, arg in enumerate(state.flow_configs[flow_id].parameters):
+                        val = activated_flow.arguments[arg.name]
+                        if (
+                            arg.name in event.arguments
+                            and val == event.arguments[arg.name]
+                        ):
+                            has_same_arguments = True
+                        elif (
+                            f"${idx}" in event.arguments
+                            and val == event.arguments[f"${idx}"]
+                        ):
+                            has_same_arguments = True
+                        else:
+                            has_same_arguments = False
+                            break
+                    if has_same_arguments:
+                        started_instance = activated_flow
+                        break
+
+            if not started_instance:
+                add_new_flow_instance(
+                    state,
+                    create_flow_instance(
+                        state.flow_configs[flow_id],
+                        event.arguments["flow_instance_uid"],
+                        event.arguments["flow_hierarchy_position"],
+                        event.arguments,
+                    ),
+                )
+            else:
+                started_event = started_instance.started_event(
+                    event.matching_scores,
+                    {"flow_instance_uid": event.arguments["flow_instance_uid"]},
+                )
+                _push_internal_event(
+                    state,
+                    started_event,
+                )
     elif event.name == InternalEvents.FINISH_FLOW:
         if "flow_instance_uid" in event.arguments:
             flow_instance_uid = event.arguments["flow_instance_uid"]

tests/v2_x/test_flow_mechanics.py

@@ -1558,7 +1558,7 @@ def test_flow_parameter_await_mechanism():
             {
                 "type": "StartUtteranceBotAction",
                 "script": "Success",
-            }
+            },
         ],
     )
 
@@ -1616,5 +1616,67 @@ def test_flow_context_sharing():
     )
 
 
+def test_single_flow_activation():
+    """Test how a parent flow can share its context with a child flow."""
+
+    content = """
+    flow a
+      start UtteranceBotAction(script="a")
+      activate z 1
+      match WaitEvent()
+
+    flow b
+      start UtteranceBotAction(script="b")
+      activate z 1
+      match WaitEvent()
+
+    flow c
+      start UtteranceBotAction(script="c")
+      activate z 2
+      match WaitEvent()
+
+    flow z $param
+      await UtteranceBotAction(script="test {$param}")
+
+    flow main
+      activate a
+      activate b
+      activate c
+      await UtteranceBotAction(script="done")
+
+    """
+
+    state = run_to_completion(_init_state(content), start_main_flow_event)
+    assert is_data_in_events(
+        state.outgoing_events,
+        [
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "a",
+            },
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "test 1",
+            },
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "b",
+            },
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "c",
+            },
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "test 2",
+            },
+            {
+                "type": "StartUtteranceBotAction",
+                "script": "done",
+            },
+        ],
+    )
+
+
 if __name__ == "__main__":
     test_meta_decorators()