thon-product-card/src/hooks/useShoppingCart.ts

este es mi paquete de pruebas para subir a NPM.

import { useState } from "react"
import { Product, ProductInCart } from "../interfaces/interfaces"


export const useShoppingCart = () => {

    const [shoppingCart, setShoppingCart] = useState<{ [key: string]: ProductInCart }>({})

    const onProductCountChange = ({ count, product }: { count: number, product: Product }) => {

        setShoppingCart(oldShoppingCart => {

            
            if (count === 0) {
                const { [product.id]: toDelete, ...rest } = oldShoppingCart
                return rest
                console.log(toDelete);
            }

            return {
                ...oldShoppingCart,
                [product.id]: { ...product, count }
            }
        })
    }


  return {
    shoppingCart,
    onProductCountChange
  }
}