Enhance get_conversation_endpoint_handler to retrieve session data correctly

- Updated the endpoint handler to first list agent sessions and then retrieve the specific session data using the session ID.
- Modified unit tests to mock the session retrieval process, ensuring the model_dump method is called correctly.

This change improves the accuracy of conversation data retrieval.

Author: jrobertboos

src/app/endpoints/conversations.py

@@ -134,7 +134,13 @@ async def get_conversation_endpoint_handler(
     try:
         client = AsyncLlamaStackClientHolder().get_client()
 
-        session_data = (await client.agents.session.list(agent_id=agent_id)).data[0]
+        agent_sessions = (await client.agents.session.list(agent_id=agent_id)).data
+        session_id = str(agent_sessions[0].get("session_id"))
+
+        session_response = await client.agents.session.retrieve(
+            agent_id=agent_id, session_id=session_id
+        )
+        session_data = session_response.model_dump()
 
         logger.info("Successfully retrieved conversation %s", conversation_id)
 

tests/unit/app/endpoints/test_conversations.py

@@ -305,6 +305,12 @@ async def test_successful_conversation_retrieval(
         mock_client.agents.session.list.return_value = mocker.Mock(
             data=[mock_session_data]
         )
+
+        # Mock session.retrieve to return an object with model_dump() method
+        mock_session_retrieve_result = mocker.Mock()
+        mock_session_retrieve_result.model_dump.return_value = mock_session_data
+        mock_client.agents.session.retrieve.return_value = mock_session_retrieve_result
+
         mock_client_holder = mocker.patch(
             "app.endpoints.conversations.AsyncLlamaStackClientHolder"
         )