javascript - Mongoose.model ('model_name' ) 当 mongoose 模型模式文件中需要函数时返回空对象

Question

如果问题的标题有误导性，我深表歉意，因为我不太确定如何解释这一点。我有 2 个文件，matchedTransaction.js 和 player.js。

sharedApi/player.js

const MatchedTransactionModel = require('../models/matchedTransaction');

// #1: If I try to console log here, the output will be an empty object "{}"
console.log(MatchedTransactionModel);

async function banPlayer(userId) {
  // ...
  // Because MatchedTransactionModel is an empty object, 
  // the code below will crash with the following error: 
  // "MatchedTransactionModel.findOne is not a function"
  const pendingMatchedTransaction = await MatchedTransactionModel.findOne({
    $and: [
      {
        $or: [
          { reserverAccountId: `${account._id}` },
          { sellerAccountId: `${account._id}` },
        ],
      },
      {
        $or: [
          { status: 'pendingReserverPayment' },
          { status: 'pendingSellerConfirmation' },
        ],
      },
    ],
  });
  // ...
}

module.exports = {
  banPlayer,
};

models/matchedTransaction.js

const mongoose = require('mongoose');
const { banPlayer } = require('../sharedApi/player');
const MatchedTransactionSchema = new mongoose.Schema([
  {
    createdDate: {
      type: Date,
      required: true,
    },
    // ...
  },
]);

MatchedTransactionSchema.post('init', async function postInit() {
    // ...
    await banPlayer(userId);
});

const MatchedTransactionModel = mongoose.model('matchedTransactions', MatchedTransactionSchema);
module.exports = MatchedTransactionModel;

请注意，在 player.js 中，当我尝试 console.log 所需的 MatchedTransactionModel 时，它返回一个空对象。但是，如果我对 ma​​tchedTransaction.js 进行以下更改:

models/matchedTransaction.js

// Instead of requiring banPlayer outside, I only require it when it is used
// const { banPlayer } = require('../sharedApi/player');

MatchedTransactionSchema.post('init', async function postInit() {
    // ...
    const { banPlayer } = require('../sharedApi/player');
    await banPlayer(userId);
});
// ...

前面提到的 console.log 的输出将是一个非空对象，并且 MatchedTransactionModel.findOne 正在按预期工作。

为什么会发生这种情况？

Answer 1

我在您的代码中看到的唯一问题是，当您在 matchedTransaction.js 上定义架构时，您传递了一个我认为有问题且没有意义的数组。您必须在那里传递一个对象:

const MatchedTransactionSchema = new mongoose.Schema({
  createdDate: {
    type: Date,
    required: true,
  },
  // ...
});