向Stripe Checkout传递MongoDB购物车动态值出错求助

将MongoDB数据库中的购物车对象传递给Stripe Checkout时遇到问题。提取cart.products数组并转换为Stripe要求的结构时，出现「无效字符串」「无法读取undefined的map」等错误。手动传入固定数组可成功，但动态生成的数组插入失败。以下是相关代码、控制台及终端输出：

相关代码（app.js） #

依赖引入 #

const express = require('express');
const app = express();
const stripe = require('stripe')(stripeSecretKey);
const User = require('./models/users');
var Cart = require('./models/cart');

接口逻辑 #

app.post('/create-checkout-session', async (req, res) => {
  const owner = req.user.id;
  const user = await User.findById(owner);
  const cart = await Cart.findOne({user: user});
  console.log(cart.products);
  // console.log(req.session.cart);//undefined
  console.log(req.session);

  const productsList = [];
  for (let i = 0; i < cart.products.length; i++) {
    const productName = cart.products[i].name;
    console.log(productName);
    const image_url = cart.products[i].image;
    const price = cart.products[i].price;
    console.log(price);
    const id = cart.products[i].id;
    console.log(id);
    const quantity = cart.products[i].quantity;

    productsList.push({productName, price, id, quantity})
    console.log(productsList)
  }

  const items = productsList.map((product) => {
    return {
      price_data: {
        currency: 'usd',
        product_data: {
          name: product.productName,
        },
        unit_amount: Number(product.price),
      },
      quantity: Number(product.quantity),
    }
  });
  console.log(items)

  try {
    const session = await stripe.checkout.sessions.create({
      payment_method_types: ['card'],
      mode: 'payment',
      line_items: items,
      success_url: `${process.env.SERVER_URL}/success.html`,
      cancel_url: `${process.env.SERVER_URL}/cancel.html`
    })
    res.json({url: session.url})
  } catch(e) {
    res.status(500).json({error: e.message})
  }
});

控制台输出 #

Invalid string: {:quantity=>"1", :id=>"65b80e868dc64e9eee697279", :productName=>"Black Mug", :price=>"2999"}

终端输出 #

[   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 2999 },     quantity: 1   },   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 2999 },     quantity: 2   },   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 3999 },     quantity: 4   },   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 3499 },     quantity: 2   },   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 4999 },     quantity: 2   },   {     price_data: { currency: 'usd', product_data: [Object], unit_amount: 4999 },     quantity: 1   } ] 

问题排查与修正要点 #

1. 变量作用域问题：原代码中productName等变量未用const/let声明，导致全局污染，在map函数中错误引用了最后一次循环的productName值，而非当前遍历的产品名称。需给循环内的变量添加const声明，并在map中使用product.productName获取当前产品名称。
2. 数据类型不匹配：Stripe要求unit_amount为数字类型、quantity为整数类型，而数据库中取出的price和quantity可能是字符串，需通过Number()转换为数字。
3. 语法错误：原代码中success_url和cancel_url的模板字符串缺失外层反引号，导致语法错误，需补充完整。

内容的提问来源于stack exchange，提问作者EgyptianG