fullcart/src/actions/updateQuantity.ts

Add stripe checkout to any website

import type { Customer } from '../schemas/customerSchema'
import type { Product } from '../schemas/productSchema'
import { customer } from '../stores/customer'
import { setQuantity } from './setQuantity'

export const updateQuantity = (
  productId: Product['id'],
  quantity: Customer['lines'][number]['quantity'],
) => {
  const lines = customer.get().lines
  const index = lines.findIndex((item) => item.productId === productId)

  if (index < 0) setQuantity(productId, quantity)
  else setQuantity(productId, lines[index].quantity += quantity)
}