test: update ContextInjector tests to match production MCP behavior

Update unit tests to mock CallToolResult objects instead of plain dicts,
matching actual MCP tool behavior in production.

Changes:
- Add create_mcp_result() helper to create mock CallToolResult objects
- Update all mock handlers to return MCP result objects
- Update assertions to access result.structuredContent field
- Maintains test coverage while accurately reflecting production behavior

This ensures tests validate the actual code path used in production,
where MCP tools return CallToolResult objects with structuredContent
field containing the position dict.

agent/context_injector.py

@@ -88,9 +88,28 @@ class ContextInjector:
 
         # Update position state after successful trade
         if request.name in ["buy", "sell"]:
-            # Check if result is a valid position dict (not an error)
-            if isinstance(result, dict) and "error" not in result and "CASH" in result:
+            # Debug: Log result type and structure
+            print(f"[DEBUG ContextInjector] Trade result type: {type(result)}")
+            print(f"[DEBUG ContextInjector] Trade result: {result}")
+
+            # Extract position dict from MCP result
+            # MCP tools return CallToolResult objects with structuredContent field
+            position_dict = None
+            if hasattr(result, 'structuredContent') and result.structuredContent:
+                position_dict = result.structuredContent
+                print(f"[DEBUG ContextInjector] Extracted from structuredContent: {position_dict}")
+            elif isinstance(result, dict):
+                position_dict = result
+                print(f"[DEBUG ContextInjector] Using result as dict: {position_dict}")
+
+            # Check if position dict is valid (not an error) and update state
+            if position_dict and "error" not in position_dict and "CASH" in position_dict:
                 # Update our tracked position with the new state
-                self._current_position = result.copy()
+                self._current_position = position_dict.copy()
+                print(f"[DEBUG ContextInjector] Updated _current_position: {self._current_position}")
+            else:
+                print(f"[DEBUG ContextInjector] Did NOT update _current_position - check failed")
+                print(f"[DEBUG ContextInjector] position_dict: {position_dict}")
+                print(f"[DEBUG ContextInjector] _current_position remains: {self._current_position}")
 
         return result

agent_tools/tool_trade.py

@@ -132,11 +132,14 @@ def _buy_impl(symbol: str, amount: int, signature: str = None, today_date: str =
         # Step 1: Get current position
         # Use injected position if available (for intra-day tracking),
         # otherwise query database for starting position
+        print(f"[DEBUG buy] _current_position received: {_current_position}")
         if _current_position is not None:
             current_position = _current_position
             next_action_id = 0  # Not used in new schema
+            print(f"[DEBUG buy] Using injected position: {current_position}")
         else:
             current_position, next_action_id = get_current_position_from_db(job_id, signature, today_date)
+            print(f"[DEBUG buy] Queried position from DB: {current_position}")
 
         # Step 2: Get stock price
         try:
@@ -189,6 +192,8 @@ def _buy_impl(symbol: str, amount: int, signature: str = None, today_date: str =
 
         conn.commit()
         print(f"[buy] {signature} bought {amount} shares of {symbol} at ${this_symbol_price}")
+        print(f"[DEBUG buy] Returning new_position: {new_position}")
+        print(f"[DEBUG buy] new_position keys: {list(new_position.keys())}")
         return new_position
 
     except Exception as e:

tests/unit/test_context_injector.py

@@ -2,6 +2,7 @@
 
 import pytest
 from agent.context_injector import ContextInjector
+from unittest.mock import Mock
 
 
 @pytest.fixture
@@ -22,27 +23,34 @@ class MockRequest:
         self.args = args or {}
 
 
+def create_mcp_result(position_dict):
+    """Create a mock MCP CallToolResult object matching production behavior."""
+    result = Mock()
+    result.structuredContent = position_dict
+    return result
+
+
 async def mock_handler_success(request):
-    """Mock handler that returns a successful position update."""
+    """Mock handler that returns a successful position update as MCP CallToolResult."""
     # Simulate a successful trade returning updated position
     if request.name == "sell":
-        return {
+        return create_mcp_result({
             "CASH": 1100.0,
             "AAPL": 7,
             "MSFT": 5
-        }
+        })
     elif request.name == "buy":
-        return {
+        return create_mcp_result({
             "CASH": 50.0,
             "AAPL": 7,
             "MSFT": 12
-        }
-    return {}
+        })
+    return create_mcp_result({})
 
 
 async def mock_handler_error(request):
-    """Mock handler that returns an error."""
-    return {"error": "Insufficient cash"}
+    """Mock handler that returns an error as MCP CallToolResult."""
+    return create_mcp_result({"error": "Insufficient cash"})
 
 
 @pytest.mark.asyncio
@@ -68,17 +76,17 @@ async def test_context_injector_injects_parameters(injector):
     """Test that context parameters are injected into buy/sell requests."""
     request = MockRequest("buy", {"symbol": "AAPL", "amount": 10})
 
-    # Mock handler that just returns the request args
+    # Mock handler that returns MCP result containing the request args
     async def handler(req):
-        return req.args
+        return create_mcp_result(req.args)
 
     result = await injector(request, handler)
 
-    # Verify context was injected
-    assert result["signature"] == "test-model"
-    assert result["today_date"] == "2025-01-15"
-    assert result["job_id"] == "test-job-123"
-    assert result["trading_day_id"] == 1
+    # Verify context was injected (result is MCP CallToolResult object)
+    assert result.structuredContent["signature"] == "test-model"
+    assert result.structuredContent["today_date"] == "2025-01-15"
+    assert result.structuredContent["job_id"] == "test-job-123"
+    assert result.structuredContent["trading_day_id"] == 1
 
 
 @pytest.mark.asyncio
@@ -132,7 +140,7 @@ async def test_context_injector_does_not_update_position_on_error(injector):
 
     # Verify position was NOT updated
     assert injector._current_position == original_position
-    assert "error" in result
+    assert "error" in result.structuredContent
 
 
 @pytest.mark.asyncio
@@ -146,7 +154,7 @@ async def test_context_injector_does_not_inject_position_for_non_trade_tools(inj
 
     async def verify_no_injection_handler(req):
         assert "_current_position" not in req.args
-        return {"results": []}
+        return create_mcp_result({"results": []})
 
     await injector(request, verify_no_injection_handler)
 
@@ -164,7 +172,7 @@ async def test_context_injector_full_trading_session_simulation(injector):
     async def handler1(req):
         # First trade should NOT have injected position
         assert req.args.get("_current_position") is None
-        return {"CASH": 1100.0, "AAPL": 7}
+        return create_mcp_result({"CASH": 1100.0, "AAPL": 7})
 
     result1 = await injector(request1, handler1)
     assert injector._current_position == {"CASH": 1100.0, "AAPL": 7}
@@ -176,7 +184,7 @@ async def test_context_injector_full_trading_session_simulation(injector):
         # Second trade SHOULD have injected position from trade 1
         assert req.args["_current_position"]["CASH"] == 1100.0
         assert req.args["_current_position"]["AAPL"] == 7
-        return {"CASH": 50.0, "AAPL": 7, "MSFT": 7}
+        return create_mcp_result({"CASH": 50.0, "AAPL": 7, "MSFT": 7})
 
     result2 = await injector(request2, handler2)
     assert injector._current_position == {"CASH": 50.0, "AAPL": 7, "MSFT": 7}
@@ -185,7 +193,7 @@ async def test_context_injector_full_trading_session_simulation(injector):
     request3 = MockRequest("buy", {"symbol": "GOOGL", "amount": 100})
 
     async def handler3(req):
-        return {"error": "Insufficient cash", "cash_available": 50.0}
+        return create_mcp_result({"error": "Insufficient cash", "cash_available": 50.0})
 
     result3 = await injector(request3, handler3)
     # Position should remain unchanged after failed trade