handeling save product with pre save method and error handlers

src/controllers/ProductController.ts

@@ -1,30 +1,16 @@
 import { Request, Response } from 'express';
 import { Product, IProduct } from '../schemas/productModel';
+import { handleCreateProductError } from '../middlewares/errorHandlers';
+
 
 export async function createProduct(req: Request, res: Response) {
   try {
-    const { name, description, price, userId } = req.body;
-    if(!name || !description || !price || !userId) {
-      res.status(400).json({ error: 'Name, description, price are required.' });
-      return;
-    }
-    
-    const productExists = await Product.exists({ name, userId });
-    if(productExists) {
-      res.status(400).json({ error: 'Product already exists.' });
-      return;
-    }
-    const product: IProduct = await Product.create({
-      name,
-      description,
-      price,
-      userId,
-    });
-
-    res.status(201).json(product);
+    const product = new Product(req.body);
+    await product.save();
+    res.json(product);
   } catch (error) {
     console.error('Error creating product:', error);
-    res.status(500).json({ error: 'An error occurred while creating the product.' });
+    handleCreateProductError(res, error);
   }
 }
 

src/middlewares/errorHandlers.ts

@@ -0,0 +1,18 @@
+import { Request, Response, NextFunction } from 'express';
+
+
+
+export function handleCreateProductError(res: Response, error: Error) {
+  let statusCode = 500;
+  let errorMessage = 'An error occurred while creating the product.';
+
+  if (error.message === 'Missing required fields.') {
+    statusCode = 400;
+    errorMessage = 'Missing required fields.';
+  } else if (error.message === 'Product already exists.') {
+    statusCode = 409;
+    errorMessage = 'Product already exists.';
+  }
+
+  res.status(statusCode).json({ error: errorMessage });
+}

src/routes/cartRouter.ts

@@ -3,8 +3,6 @@ import { authenticateToken } from '../middlewares/checkAuth';
 import { addToCart, listCart, checkout, clearCart } from '../controllers/cartController';
 import { checkUuid } from '../middlewares/checkUuid'; 
 
-
-
 const cartRouter = express.Router();
 
 cartRouter.post('/', [authenticateToken], addToCart);

src/schemas/orderModel.ts

@@ -1,7 +1,5 @@
 import mongoose, { Schema, Document } from 'mongoose';
 
-
-
 interface IOrder extends Document {
   userId: string;
   products: { [itemId: string]: number };

src/schemas/productModel.ts

@@ -1,4 +1,5 @@
 import mongoose, { Schema, Document } from 'mongoose';
+import { Request } from 'express';
 
 interface IProduct extends Document {
   name: string;
@@ -18,10 +19,27 @@ const ProductSchema: Schema = new Schema({
   updatedAt: { type: Date, default: Date.now },
 });
 
-const Product = mongoose.model<IProduct>('Product', ProductSchema);
+ProductSchema.pre('save', async function (next) {
+  try {
+    if (!this.name || !this.description || !this.price || !this.userId) {
+      throw new Error('Missing required fields.');
+    }
 
+    const productExists = await mongoose.model<IProduct>('Product').exists({ name: this.name, userId: this.userId });
+    if (productExists) {
+      throw new Error('Product already exists.');
+    }
+
+    next();
+  } catch (error) {
+    next(error);
+  }
+});
+
+const Product = mongoose.model<IProduct>('Product', ProductSchema);
 ProductSchema.index({ name: 1, userId: 1 }, { unique: true });
 
+
 export {
   Product,
   IProduct