import { CartItem } from '@/constants/types'; export const calculateTotal = (items: CartItem[]): number => { return items.reduce((total, item) => { return total + item.price * item.quantity; }, 0); }; export const updateItemQuantity = ( items: CartItem[], itemId: string, newQuantity: number ): CartItem[] => { if (newQuantity < 0) { return items; } return items.map((item) => item.id === itemId ? { ...item, quantity: newQuantity } : item ); };