fix(api): GET /task 内存失后 DB fallback 返 status(治回测 done 后前端轮询 404 死循环卡等待) [nas]

tests/api/test_task_status_db_fallback.py

@@ -0,0 +1,37 @@
+"""GET /task/{id} 内存失后 DB fallback (治 done task 内存清后前端轮询 404 死循环卡等待)。"""
+from fastapi.testclient import TestClient
+
+from sanguo_api.app import create_app
+from sanguo_api.auth import set_jwt_config, create_token
+from sanguo_backtest.result_store import BacktestResult, save_result
+
+
+def _auth_client(tmp_path):
+    set_jwt_config("test_secret_dbfb", 60)
+    db = str(tmp_path / "r.db")
+    app = create_app(db_path=db)
+    c = TestClient(app)
+    token = create_token("admin")
+    return c, {"Authorization": f"Bearer {token}"}, db
+
+
+def test_get_status_returns_done_when_only_in_db(tmp_path):
+    """内存池无(容器重启/清理)但 DB 有 done 结果 → 返回 done,不 404。"""
+    c, h, db = _auth_client(tmp_path)
+    save_result(
+        BacktestResult(
+            task_id="cta_dbfb", type="cta", status="done", strategy="DoubleMa",
+            symbol="600519.SH", params={}, start="2024-01-02", end="2024-03-29",
+            statistics={}, equity_curve=None, trades=None,
+        ),
+        db_path=db,
+    )
+    r = c.get("/api/v1/task/cta_dbfb", headers=h)
+    assert r.status_code == 200
+    assert r.json()["status"] == "done"
+
+
+def test_get_status_404_when_neither_memory_nor_db(tmp_path):
+    c, h, _db = _auth_client(tmp_path)
+    r = c.get("/api/v1/task/nonexistent_xyz", headers=h)
+    assert r.status_code == 404