fix(topic_safety): handle InternalEvent objects in topic safety actions for Colang 2.0 (#1335)

Convert InternalEvent objects to dictionary format before passing to to_chat_messages() to prevent
'InternalEvent' object is not subscriptable TypeError when using topic safety with Colang 2.0 runtime.

Author: Pouyanpi

nemoguardrails/library/topic_safety/actions.py

@@ -46,7 +46,17 @@ async def topic_safety_check_input(
         model_name = model_name or context.get("model", None)
 
     if events is not None:
-        conversation_history = to_chat_messages(events)
+        # convert InternalEvent objects to dictionary format for compatibility with to_chat_messages
+        dict_events = []
+        for event in events:
+            if hasattr(event, "name") and hasattr(event, "arguments"):
+                dict_event = {"type": event.name}
+                dict_event.update(event.arguments)
+                dict_events.append(dict_event)
+            else:
+                dict_events.append(event)
+
+        conversation_history = to_chat_messages(dict_events)
 
     if model_name is None:
         error_msg = (

tests/test_topic_safety_internalevent.py

@@ -0,0 +1,74 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Test for InternalEvent handling in topic_safety_check_input action."""
+
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from nemoguardrails.colang.v2_x.runtime.flows import InternalEvent
+from nemoguardrails.library.topic_safety.actions import topic_safety_check_input
+
+
+@pytest.mark.asyncio
+async def test_topic_safety_check_input_with_internal_events():
+    """Test that topic_safety_check_input can handle InternalEvent objects without failing.
+
+    This test would fail before the fix with:
+    TypeError: 'InternalEvent' object is not subscriptable
+    """
+    internal_events = [
+        InternalEvent(
+            name="UtteranceUserActionFinished",
+            arguments={"final_transcript": "Hello, how are you?"},
+        ),
+        InternalEvent(
+            name="StartUtteranceBotAction",
+            arguments={"script": "I'm doing well, thank you!"},
+        ),
+    ]
+
+    class MockTaskManager:
+        def render_task_prompt(self, task):
+            return "Check if the conversation is on topic."
+
+        def get_stop_tokens(self, task):
+            return []
+
+        def get_max_tokens(self, task):
+            return 10
+
+    llms = {"topic_control": "mock_llm"}
+    llm_task_manager = MockTaskManager()
+
+    with patch(
+        "nemoguardrails.library.topic_safety.actions.llm_call", new_callable=AsyncMock
+    ) as mock_llm_call:
+        mock_llm_call.return_value = "on-topic"
+
+        # should not raise TypeError: 'InternalEvent' object is not subscriptable
+        result = await topic_safety_check_input(
+            llms=llms,
+            llm_task_manager=llm_task_manager,
+            model_name="topic_control",
+            context={"user_message": "Hello"},
+            events=internal_events,
+        )
+
+    assert isinstance(result, dict)
+    assert "on_topic" in result
+    assert isinstance(result["on_topic"], bool)
+    assert result["on_topic"] is True