fix: backtest submission shows no results — 4 bugs fixed

- ID mismatch: API generated a throwaway UUID while BacktestReplay
  generated its own internally. Frontend polled with wrong ID and
  never found the DB row. Now pre-generate ID in endpoint and pass
  it to BacktestReplay.
- Field name: API returned 'backtest_id' but frontend read 'data.id'.
  Unified to 'id' everywhere.
- No polling: useBacktestResult fired once and never refreshed.
  Added refetchInterval that polls every 2s while status is running.
- Response shape: GET endpoint nested results under 'result' object
  but frontend expected flat fields. Flattened response to match
  BacktestResult type.
- Added running/failed/completed status indicators in BacktestPanel.

frontend/src/api/tradingHooks.ts

@@ -234,12 +234,17 @@ export function useTradingConfig() {
   });
 }
 
-/** Fetch a backtest result by ID. */
+/** Fetch a backtest result by ID. Polls every 2s while status is pending/running. */
 export function useBacktestResult(id: string | undefined) {
   return useQuery<BacktestResult>({
     queryKey: ['backtest-result', id],
     queryFn: () => apiGet<BacktestResult>('trading', `/api/trading/backtest/${id}`),
     enabled: !!id,
+    refetchInterval: (query) => {
+      const status = query.state.data?.status;
+      if (!status || status === 'running' || status === 'pending') return 2000;
+      return false;
+    },
   });
 }
 

frontend/src/pages/trading/BacktestPanel.tsx

@@ -25,7 +25,7 @@ export function BacktestPanel() {
   const [backtestId, setBacktestId] = useState<string | undefined>(undefined);
 
   const launch = useBacktestLaunch();
-  const { data: result, isLoading: resultLoading } = useBacktestResult(backtestId);
+  const { data: result } = useBacktestResult(backtestId);
 
   function handleLaunch() {
     if (!startDate || !endDate) return;
@@ -108,8 +108,28 @@ export function BacktestPanel() {
       </Card>
 
       {/* Results */}
-      {resultLoading && <LoadingSpinner />}
+      {backtestId && !result && (
-      {result && (
+        <Card>
+          <div className="flex items-center gap-3">
+            <LoadingSpinner />
+            <span className="text-sm text-gray-400">Backtest running…</span>
+          </div>
+        </Card>
+      )}
+      {result && result.status === 'running' && (
+        <Card>
+          <div className="flex items-center gap-3">
+            <LoadingSpinner />
+            <span className="text-sm text-gray-400">Backtest in progress…</span>
+          </div>
+        </Card>
+      )}
+      {result && result.status === 'failed' && (
+        <Card>
+          <p className="text-sm text-red-400">Backtest failed. Check server logs for details.</p>
+        </Card>
+      )}
+      {result && result.status === 'completed' && (
         <>
           {/* Summary Metrics */}
           <Card>

services/trading/app.py

@@ -14,7 +14,7 @@ from __future__ import annotations
 import logging
 import uuid
 from contextlib import asynccontextmanager
-from datetime import datetime, timezone
+from datetime import date, datetime, timezone
 from typing import Any, Optional
 
 import asyncpg
@@ -490,6 +490,8 @@ async def launch_backtest(body: BacktestRequest) -> dict[str, str]:
     """Launch a backtest run and return its ID.
 
     Task 32.5: Uses BacktestReplay to run the backtest in a background task.
+    The backtest_id is pre-generated and passed to BacktestReplay so the
+    frontend can poll for results using the same ID.
     """
     if engine is None:
         raise HTTPException(503, "Engine not initialised")
@@ -499,6 +501,8 @@ async def launch_backtest(body: BacktestRequest) -> dict[str, str]:
     from services.trading.backtest_replay import BacktestReplay
     from services.trading.backtester import BacktestConfig
 
+    backtest_id = str(uuid.uuid4())
+
     bt_config = BacktestConfig(
         start_date=date_type.fromisoformat(body.start_date),
         end_date=date_type.fromisoformat(body.end_date),
@@ -512,15 +516,12 @@ async def launch_backtest(body: BacktestRequest) -> dict[str, str]:
 
     async def _run_backtest():
         try:
-            await replay.run(bt_config)
+            await replay.run(bt_config, backtest_id=backtest_id)
         except Exception:
             logger.exception("Backtest failed")
 
     asyncio.create_task(_run_backtest())
-    # Generate a backtest_id — the replay generates its own, but we return
+    return {"id": backtest_id, "status": "running"}
-    # a placeholder immediately. The actual ID is in backtest_runs table.
-    backtest_id = str(uuid.uuid4())
-    return {"backtest_id": backtest_id, "status": "running"}
 
 
 @app.get("/api/trading/backtest/{backtest_id}")
@@ -528,14 +529,12 @@ async def get_backtest(backtest_id: str) -> dict[str, Any]:
     """Retrieve backtest results from PostgreSQL.
 
     Task 32.5: Queries backtest_runs and backtest_trades tables.
+    Returns a flat object matching the frontend BacktestResult type.
     """
     if engine is None or engine.pool is None:
-        # Fallback for when pool is not available
         return {
-            "backtest_id": backtest_id,
+            "id": backtest_id,
             "status": "pending",
-            "config": None,
-            "result": None,
         }
 
     try:
@@ -545,25 +544,23 @@ async def get_backtest(backtest_id: str) -> dict[str, Any]:
         )
         if row is None:
             return {
-                "backtest_id": backtest_id,
+                "id": backtest_id,
                 "status": "not_found",
-                "config": None,
-                "result": None,
             }
 
         row_dict = dict(row)
-        # Convert non-serializable types
+
-        for key, val in row_dict.items():
+        # Parse equity_curve from JSONB
-            if isinstance(val, (datetime,)):
+        equity_curve = row_dict.get("equity_curve", [])
-                row_dict[key] = val.isoformat()
+        if isinstance(equity_curve, str):
-            elif hasattr(val, "__str__") and not isinstance(val, (str, int, float, bool, type(None))):
+            import json as _json
-                row_dict[key] = str(val)
+            equity_curve = _json.loads(equity_curve)
 
         # Fetch trades
         trades = []
         try:
             trade_rows = await engine.pool.fetch(
-                "SELECT * FROM backtest_trades WHERE backtest_id = $1",
+                "SELECT * FROM backtest_trades WHERE backtest_id = $1 ORDER BY created_at",
                 backtest_id,
             )
             for tr in trade_rows:
@@ -571,6 +568,8 @@ async def get_backtest(backtest_id: str) -> dict[str, Any]:
                 for key, val in trade_dict.items():
                     if isinstance(val, (datetime,)):
                         trade_dict[key] = val.isoformat()
+                    elif isinstance(val, date):
+                        trade_dict[key] = val.isoformat()
                     elif hasattr(val, "__str__") and not isinstance(val, (str, int, float, bool, type(None))):
                         trade_dict[key] = str(val)
                 trades.append(trade_dict)
@@ -578,32 +577,29 @@ async def get_backtest(backtest_id: str) -> dict[str, Any]:
             pass
 
         return {
-            "backtest_id": backtest_id,
+            "id": str(row_dict.get("id", backtest_id)),
+            "start_date": str(row_dict.get("start_date", "")),
+            "end_date": str(row_dict.get("end_date", "")),
+            "initial_capital": row_dict.get("initial_capital"),
+            "risk_tier": row_dict.get("risk_tier"),
+            "config": row_dict.get("config", {}),
+            "total_return": row_dict.get("total_return"),
+            "sharpe_ratio": row_dict.get("sharpe_ratio"),
+            "max_drawdown": row_dict.get("max_drawdown"),
+            "win_rate": row_dict.get("win_rate"),
+            "profit_factor": row_dict.get("profit_factor"),
+            "trade_count": row_dict.get("trade_count"),
+            "equity_curve": equity_curve,
+            "trades": trades,
             "status": row_dict.get("status", "unknown"),
-            "config": {
+            "completed_at": row_dict["completed_at"].isoformat() if row_dict.get("completed_at") else None,
-                "start_date": str(row_dict.get("start_date", "")),
+            "created_at": row_dict["created_at"].isoformat() if row_dict.get("created_at") else None,
-                "end_date": str(row_dict.get("end_date", "")),
-                "initial_capital": row_dict.get("initial_capital"),
-                "risk_tier": row_dict.get("risk_tier"),
-            },
-            "result": {
-                "total_return": row_dict.get("total_return"),
-                "sharpe_ratio": row_dict.get("sharpe_ratio"),
-                "max_drawdown": row_dict.get("max_drawdown"),
-                "win_rate": row_dict.get("win_rate"),
-                "profit_factor": row_dict.get("profit_factor"),
-                "trade_count": row_dict.get("trade_count"),
-                "equity_curve": row_dict.get("equity_curve"),
-                "trades": trades,
-            },
         }
     except Exception:
         logger.debug("Could not query backtest results — tables may not exist")
         return {
-            "backtest_id": backtest_id,
+            "id": backtest_id,
             "status": "pending",
-            "config": None,
-            "result": None,
         }
 
 

services/trading/backtest_replay.py

@@ -39,16 +39,18 @@ class BacktestReplay:
         self.pool = pool
         self._perf = PerformanceComputer()
 
-    async def run(self, config: BacktestConfig) -> BacktestResult:
+    async def run(self, config: BacktestConfig, backtest_id: str | None = None) -> BacktestResult:
         """Execute a full backtest replay.
 
         Args:
             config: Backtest configuration (date range, capital, risk tier).
+            backtest_id: Optional pre-generated ID. If not provided, one is generated.
 
         Returns:
             BacktestResult with metrics, trade log, and equity curve.
         """
-        backtest_id = str(uuid.uuid4())
+        if backtest_id is None:
+            backtest_id = str(uuid.uuid4())
 
         try:
             # Fetch historical recommendations

tests/test_pbt_trading_api.py

@@ -222,7 +222,7 @@ class TestProperty29PersistenceRoundTrip:
         assert isinstance(resp.json()["ready"], bool)
 
     def test_backtest_returns_id(self) -> None:
-        """POST /api/trading/backtest returns a backtest_id string."""
+        """POST /api/trading/backtest returns an id string."""
         client = _get_client()
         resp = client.post(
             "/api/trading/backtest",
@@ -235,9 +235,9 @@ class TestProperty29PersistenceRoundTrip:
         )
         assert resp.status_code == 200
         data = resp.json()
-        assert "backtest_id" in data
+        assert "id" in data
-        assert isinstance(data["backtest_id"], str)
+        assert isinstance(data["id"], str)
-        assert len(data["backtest_id"]) > 0
+        assert len(data["id"]) > 0
 
     def test_backtest_get_returns_placeholder(self) -> None:
         """GET /api/trading/backtest/{id} returns a result dict."""
@@ -246,7 +246,7 @@ class TestProperty29PersistenceRoundTrip:
         resp = client.get(f"/api/trading/backtest/{test_id}")
         assert resp.status_code == 200
         data = resp.json()
-        assert data["backtest_id"] == test_id
+        assert data["id"] == test_id
 
     def test_decisions_returns_list(self) -> None:
         """GET /api/trading/decisions returns a list."""