Refactor: Don't serialize matching events when searching event stream (#6509)

openhands/events/stream.py

@@ -384,7 +384,7 @@ class EventStream:
         start_id: int = 0,
         limit: int = 100,
         reverse: bool = False,
-    ) -> list:
+    ) -> list[type[Event]]:
         """Get matching events from the event stream based on filters.
 
         Args:
@@ -414,7 +414,7 @@ class EventStream:
             ):
                 continue
 
-            matching_events.append(event_to_dict(event))
+            matching_events.append(event)
 
             # Stop if we have enough events
             if len(matching_events) >= limit:

openhands/server/routes/conversation.py

@@ -3,7 +3,7 @@ from fastapi.responses import JSONResponse
 
 from openhands.core.logger import openhands_logger as logger
 from openhands.events.event import Event
-from openhands.events.serialization.event import event_from_dict
+from openhands.events.serialization.event import event_from_dict, event_to_dict
 from openhands.runtime.base import Runtime
 
 app = APIRouter(prefix='/api/conversations/{conversation_id}')
@@ -156,6 +156,8 @@ async def search_events(
     has_more = len(matching_events) > limit
     if has_more:
         matching_events = matching_events[:limit]  # Remove the extra event
+
+    matching_events = [event_to_dict(event) for event in matching_events]
     return {
         'events': matching_events,
         'has_more': has_more,

tests/unit/test_event_stream.py

@@ -3,6 +3,7 @@ import json
 import pytest
 from pytest import TempPathFactory
 
+from openhands.core.schema.observation import ObservationType
 from openhands.events import EventSource, EventStream
 from openhands.events.action import (
     NullAction,
@@ -78,12 +79,15 @@ def test_get_matching_events_type_filter(temp_dir: str):
     # Filter by NullAction
     events = event_stream.get_matching_events(event_types=(NullAction,))
     assert len(events) == 2
-    assert all(e['action'] == 'null' for e in events)
+    assert all(isinstance(e, NullAction) for e in events)
 
     # Filter by NullObservation
     events = event_stream.get_matching_events(event_types=(NullObservation,))
     assert len(events) == 1
-    assert events[0]['observation'] == 'null'
+    assert (
+        isinstance(events[0], NullObservation)
+        and events[0].observation == ObservationType.NULL
+    )
 
     # Filter by NullAction and MessageAction
     events = event_stream.get_matching_events(event_types=(NullAction, MessageAction))
@@ -91,7 +95,7 @@ def test_get_matching_events_type_filter(temp_dir: str):
 
     # Filter in reverse
     events = event_stream.get_matching_events(reverse=True, limit=1)
-    assert events[0]['message'] == 'test'
+    assert isinstance(events[0], MessageAction) and events[0].content == 'test'
 
 
 def test_get_matching_events_query_search(temp_dir: str):
@@ -126,12 +130,17 @@ def test_get_matching_events_source_filter(temp_dir: str):
     # Filter by AGENT source
     events = event_stream.get_matching_events(source='agent')
     assert len(events) == 2
-    assert all(e['source'] == 'agent' for e in events)
+    assert all(
+        isinstance(e, NullObservation) and e.source == EventSource.AGENT for e in events
+    )
 
     # Filter by ENVIRONMENT source
     events = event_stream.get_matching_events(source='environment')
     assert len(events) == 1
-    assert events[0]['source'] == 'environment'
+    assert (
+        isinstance(events[0], NullObservation)
+        and events[0].source == EventSource.ENVIRONMENT
+    )
 
 
 def test_get_matching_events_pagination(temp_dir: str):
@@ -149,13 +158,13 @@ def test_get_matching_events_pagination(temp_dir: str):
     # Test start_id
     events = event_stream.get_matching_events(start_id=2)
     assert len(events) == 3
-    assert events[0]['content'] == 'test2'
+    assert isinstance(events[0], NullObservation) and events[0].content == 'test2'
 
     # Test combination of start_id and limit
     events = event_stream.get_matching_events(start_id=1, limit=2)
     assert len(events) == 2
-    assert events[0]['content'] == 'test1'
-    assert events[1]['content'] == 'test2'
+    assert isinstance(events[0], NullObservation) and events[0].content == 'test1'
+    assert isinstance(events[1], NullObservation) and events[1].content == 'test2'
 
 
 def test_get_matching_events_limit_validation(temp_dir: str):