feat(api): Synchronize history and summary from DB in chat stream

backend/tests/api/test_history_sync.py

@@ -0,0 +1,79 @@
+import pytest
+from fastapi.testclient import TestClient
+from unittest.mock import MagicMock, patch
+from ea_chatbot.api.main import app
+from ea_chatbot.history.models import User, Conversation, Message
+from langchain_core.messages import HumanMessage, AIMessage
+
+@pytest.fixture
+def client():
+    return TestClient(app)
+
+@pytest.fixture
+def mock_user():
+    return User(id="user-123", username="test@test.com")
+
+def test_chat_stream_loads_history(client, mock_user):
+    """
+    Test that the /chat/stream endpoint loads history from the DB
+    and passes it to stream_agent_events.
+    """
+    # 1. Setup mocks
+    from ea_chatbot.api.dependencies import get_current_user
+    app.dependency_overrides[get_current_user] = lambda: mock_user
+    
+    try:
+        with patch("ea_chatbot.api.routers.agent.history_manager") as mock_hm, \
+             patch("ea_chatbot.api.routers.agent.stream_agent_events") as mock_stream:
+            
+            # Mock conversation exists and belongs to user
+            mock_conv = Conversation(id="conv-123", user_id=mock_user.id, summary="Old summary")
+            
+            mock_session = MagicMock()
+            mock_session.get.return_value = mock_conv
+            mock_hm.get_session.return_value.__enter__.return_value = mock_session
+            
+            # Mock history window returns some messages
+            mock_db_messages = [
+                Message(role="user", content="Question 1"),
+                Message(role="assistant", content="Answer 1")
+            ]
+            mock_hm.get_messages_by_window.return_value = mock_db_messages
+            
+            # Mock stream_agent_events to return an empty generator
+            async def empty_gen(*args, **kwargs):
+                yield 'data: {"type": "done"}\n\n'
+            
+            mock_stream.side_effect = empty_gen
+            
+            # 2. Execute request
+            response = client.post(
+                "/api/v1/chat/stream",
+                json={"message": "New question", "thread_id": "conv-123"}
+            )
+            
+            # 3. Assertions
+            assert response.status_code == 200
+            
+            # Verify history_manager was called to get history
+            mock_hm.get_messages_by_window.assert_called_once_with("conv-123", window_size=10)
+            
+            # Verify stream_agent_events was called with loaded history and summary
+            args, kwargs = mock_stream.call_args
+            # args: message, thread_id, user_id, summary, messages
+            assert args[0] == "New question"
+            assert args[1] == "conv-123"
+            assert args[2] == mock_user.id
+            assert args[3] == "Old summary"
+            
+            passed_messages = args[4]
+            assert len(passed_messages) == 2
+            assert isinstance(passed_messages[0], HumanMessage)
+            assert passed_messages[0].content == "Question 1"
+            assert isinstance(passed_messages[1], AIMessage)
+            assert passed_messages[1].content == "Answer 1"
+            
+            # Verify current message was saved AFTER loading history (based on code logic)
+            mock_hm.add_message.assert_called_with("conv-123", "user", "New question")
+    finally:
+        app.dependency_overrides.clear()