猫鼬不推入数组

我的代码是：

模型：

var mongoose = require('mongoose');

var eventSchema = new mongoose.Schema({
    'eventTitle': String,
    'location': String,
    'startDate': String,
    'endDate': String,
    'startTime': String,
    'endTime': String,
    'createdBy': mongoose.Schema.Types.ObjectId, // Here we will store the _ID from the user EOSP.
    'attendants': {
        'seekers': [mongoose.Schema.Types.ObjectId],
        'employers': [],
    },
    'isFinished': {'type': Boolean, 'default': false},
    'uploadedResumes': Number,
    'downloadedResumes': Number,
    'survey': {
        'seekers': [],
        'employers': [],
        'host': [],
    }
});

module.exports = mongoose.model('event', eventSchema);

路由器：

.post(async (req, res) => {
    let {user, params} = req;
    let {eid, uid} = params;
    eid = mongoose.Types.ObjectId(eid);
    uid = mongoose.Types.ObjectId(uid);

    user = user ? user : await Account.findById(uid).catch(e => console.log(e));
    if (user.accType.toLowerCase() === 'seeker') {
        const {
            rating,
            recommendation,
            websiteEaseOfUse,
            chatHelpfulness,
            skillsSuitability,
            tips,
        } = req.body;
        const data = {
            userId: user._id,
            rating,
            recommendation,
            websiteEaseOfUse,
            chatHelpfulness,
            skillsSuitability,
            tips,
        };
        console.log(data);
        Event.findOneAndUpdate({'_id': eid}, {
            $push: {
                'survey.seeker': {
                    userId: user._id,
                    rating,
                    recommendation,
                    websiteEaseOfUse,
                    chatHelpfulness,
                    skillsSuitability,
                    tips,
                },
            },
        }, {$upsert: true,}).then(r => console.log('pushed', r.survey.seekers)).catch(e => console.log(e));
    }
    const title = await Event.findById(eid).then(r => r.eventTitle).catch(e => console.log(e));
    const event = await functions.getCurrentEvent();
    res.render('survey/thanks', {
        title: title,
        user: user,
        event: event
    })
});

因此，这段代码应该做的是，将通过post传递到路由器的数据（实际上是可行的），然后将其推入数组中（这是不可行的）。

这是日志：

pushed []

所以我的问题是，为什么即使控制台说它已通过（console.log（'push'）），它也没有将数据放入其中？我想念什么？