diff --git a/src/controllers/product.controller.ts b/src/controllers/product.controller.ts
index 1979758..cad37a4 100644
--- a/src/controllers/product.controller.ts
+++ b/src/controllers/product.controller.ts
@@ -23,6 +23,10 @@ export class ProductController {
   static async update(req: Request, res: Response, next: NextFunction) {
     try {
       const { id } = req.params;
+      if (typeof id !== "string") {
+        res.status(400);
+        return next({ statusCode: 400, message: "Invalid product id" });
+      }
       const product = await ProductService.update(id, req.body);
       res.status(200).json(product);
     } catch (err) {
diff --git a/src/repositories/order.repo.ts b/src/repositories/order.repo.ts
index 305ba62..8103e6a 100644
--- a/src/repositories/order.repo.ts
+++ b/src/repositories/order.repo.ts
@@ -6,7 +6,7 @@ export class OrderRepository {
     data: Omit<OrderDocument, "_id" | "createdAt" | "updatedAt">,
     session: ClientSession,
   ): Promise<OrderDocument> {
-    return OrderModel.create([data], { session }).then((res) => res[0]);
+    return OrderModel.create(data, { session });
   }
 
   static findById(id: string, session?: ClientSession) {
@@ -21,7 +21,14 @@ export class OrderRepository {
     return OrderModel.find({ userId }).lean();
   }
 
-  static save(order: OrderDocument, session?: ClientSession) {
-    return order.save({ session });
+  static save(
+    order: OrderDocument & {
+      save: (options?: {
+        session?: ClientSession | null;
+      }) => Promise<OrderDocument>;
+    },
+    session?: ClientSession,
+  ) {
+    return order.save({ session: session ?? null });
   }
 }
diff --git a/src/services/order.service.ts b/src/services/order.service.ts
index 50992b1..07f877b 100644
--- a/src/services/order.service.ts
+++ b/src/services/order.service.ts
@@ -3,6 +3,15 @@ import { ProductRepository } from "../repositories/product.repo.js";
 import { OrderRepository } from "../repositories/order.repo.js";
 
 export class OrderService {
+  static listOrders(userId: string, role: string) {
+    throw new Error("Method not implemented.");
+  }
+  static payOrder(id: string | string[] | undefined) {
+    throw new Error("Method not implemented.");
+  }
+  static cancelOrder(id: string | string[] | undefined) {
+    throw new Error("Method not implemented.");
+  }
   static async createOrder(
     userId: string,
     items: { productId: string; quantity: number }[],