NodeJS：使用 Mongoose 發布訂單時出錯

Question

我正在使用 NodeJS 和 Mongoose，它是一個購物車。 我在發布訂單時遇到錯誤。

這是錯誤 output：

Error: Order validation failed: user.userId: Path `user.userId` is required.
    at ValidationError.inspect (/opt/sourcecode/sandboxnodejs/node_modules/mongoose/lib/error/validation.js:48:26)
    at formatValue (node:internal/util/inspect:763:19)
    at inspect (node:internal/util/inspect:340:10)
    at formatWithOptionsInternal (node:internal/util/inspect:2006:40)
    at formatWithOptions (node:internal/util/inspect:1888:10)
    at console.value (node:internal/console/constructor:323:14)
    at console.log (node:internal/console/constructor:359:61)
    at /opt/sourcecode/sandboxnodejs/controllers/shop.js:108:29
    at processTicksAndRejections (node:internal/process/task_queues:96:5) {
  errors: {
    'user.userId': ValidatorError: Path `user.userId` is required.
        at validate (/opt/sourcecode/sandboxnodejs/node_modules/mongoose/lib/schematype.js:1277:13)
        at /opt/sourcecode/sandboxnodejs/node_modules/mongoose/lib/schematype.js:1260:7
        at Array.forEach (<anonymous>)
        at ObjectId.SchemaType.doValidate (/opt/sourcecode/sandboxnodejs/node_modules/mongoose/lib/schematype.js:1210:14)
        at /opt/sourcecode/sandboxnodejs/node_modules/mongoose/lib/document.js:2700:18
        at processTicksAndRejections (node:internal/process/task_queues:78:11) {
      properties: [Object],
      kind: 'required',
      path: 'user.userId',
      value: undefined,
      reason: undefined,
      [Symbol(mongoose:validatorError)]: true
    }
  },
  _message: 'Order validation failed'
}

這是指向要點的鏈接： https://gist.github.com/hftamayo/bba430df7070bf6d141aeddcbb698716

controller中觸發此錯誤的主要方法是這樣的：

exports.postOrder = (req, res, next) => {
  req.user
    .populate("cart.items.productId")
    .then((user) => {
      const products = user.cart.items.map((i) => {
        return { quantity: i.quantity, product: { ...i.productId._doc } };
      });
      const order = new Order({
        user: {
          name: req.user.name,
          userId: req.user.userId
        },
        products: products,
      });
      return order.save();
    })
    .then((result) => {
      return req.user.clearCart();
    })
    .then(() => {
      res.redirect("/orders");
    })
    .catch((err) => console.log(err));
};

回購是這個：https://github.com/hftamayo/sandboxnodejs/tree/chapt12_mongoose

其他涉及的組件包括：

shop.js (controller)
user.js (model)
order.js (model)

我有幾天嘗試調試它，我知道 userId 是 null 但我不明白為什么，任何提示將不勝感激。

最好的祝願

Answer 1

該錯誤與未定義的參數（userId）有關：

user: {
          name: req.user.name,
          userId: req.user.userId
        },

所以，這成功了：

user: {
          name: req.user.name,
          userId: req.user._id
        },