Mongoose findOneAndUpdate（）问题

Question

我正在尝试更新文档，如果存在，则创建一个新文档

我已将UserId设置为唯一值并尝试使用该条件进行更新

let saveUser = User({
        UserId: msg.from.id,
        FirstName: msg.from.first_name,
        LastName: msg.from.last_name,
        IsAdmin: false,
        Active: true,
        EoS: null,
        Stake: 0,
        Binance: false,
        Poloniex: false,
        Bittrex: false
    });
    User.findOneAndUpdate({UserId: msg.from.id}, saveUser, {upsert: true}, function (err, user) {
        if (err)
            console.log(err);
        else
            console.log('User registered');

    });

这导致以下错误

{ MongoError: Performing an update on the path '_id' would modify the immutable field '_id'
    at /Users/orion/NODE/CryptoBot/node_modules/mongodb-core/lib/connection/pool.js:595:61
    at authenticateStragglers (/Users/orion/NODE/CryptoBot/node_modules/mongodb-core/lib/connection/pool.js:513:16)
    at Connection.messageHandler (/Users/orion/NODE/CryptoBot/node_modules/mongodb-core/lib/connection/pool.js:549:5)
    at emitMessageHandler (/Users/orion/NODE/CryptoBot/node_modules/mongodb-core/lib/connection/connection.js:309:10)
    at Socket.<anonymous> (/Users/orion/NODE/CryptoBot/node_modules/mongodb-core/lib/connection/connection.js:452:17)
    at Socket.emit (events.js:160:13)
    at addChunk (_stream_readable.js:269:12)
    at readableAddChunk (_stream_readable.js:256:11)
    at Socket.Readable.push (_stream_readable.js:213:10)
    at TCP.onread (net.js:599:20)
  name: 'MongoError',
  message: 'Performing an update on the path \'_id\' would modify the immutable field \'_id\'',
  ok: 0,
  errmsg: 'Performing an update on the path \'_id\' would modify the immutable field \'_id\'',
  code: 66,
  codeName: 'ImmutableField' }

如何阻止_id被修改？或者一般如何解决这个问题？

不重复，因为我按照导致此问题的链接中的解决方案