I’m developing an e-commerce application using Express.js, Mongoose, and MongoDB. I’m facing an issue when trying to clear a user’s cart. The goal is to delete all items in the cart for the currently authenticated user. However, I keep encountering the following error message:

Context

1. Backend Framework: Node.js with Express
2. Database: MongoDB with Mongoose ORM
3. Authentication: JWT

Problem Description

I have a clearCart function in my cart controller that is supposed to delete all cart items for the logged-in user. The user ID is extracted from the JWT token using middleware.

Relevant Code

cartController.js

const asyncHandler = require('express-async-handler');
const Cart = require('../models/cartModel');
const mongoose = require('mongoose');

const clearCart = asyncHandler(async (req, res) => {
    try {
        console.log("User in clearCart controller:", req.user);

        if (!req.user) {
            res.status(401).json({ message: "Not authorized, user not found" });
            return;
        }

        const userId = mongoose.Types.ObjectId(req.user._id);
        console.log("User ID:", userId);
        await Cart.deleteMany({ user: userId });
        console.log("Cart cleared for user:", userId);
        res.status(200).json({ message: 'Cart cleared' });
    } catch (error) {
        console.error("Error clearing cart:", error);
        res.status(500).json({ error: error.message });
    }
});

module.exports = { clearCart }; ```

const mongoose = require('mongoose');

const cartSchema = mongoose.Schema(
    {
        productId: {
            type: String,
            required: true,
            ref: "BookUpload",
        },
        user: {
            type: mongoose.Schema.Types.ObjectId,
            required: true,
            ref: "User",
        },
        quantity: {
            type: Number,
            required: true,
            default: 1,
        }
    },
    {
        timestamps: true,
    }
);

const Cart = mongoose.model("Cart", cartSchema);

module.exports = Cart;