对findOneAndUpdate的验证无法访问＆＃34;这个＆＃34;值

Question

我有一个Express端点执行以下操作：

router.put('/:appointmentId', async (req, res) => {
  try {
    let appointment = await Appointment.findOneAndUpdate(
      { _id: req.params.appointmentId },
      {
        member_id: req.body.appointment.memberId,
        client_id: req.body.appointment.clientId,
        address_id: req.body.appointment.addressId,
        unit_id: req.body.appointment.unitId,
        dateAndTime: req.body.appointment.dateAndTime
      },
      {
        new: true,
        runValidators: true,
        context: 'query'
      }
    );

    res.send(appointment);

  } catch (err) {
    res.send(err);
  }
});

约会是一种猫鼬模型。此模型具有以下路径验证之一：

AppointmentSchema.path("unit_id").validate(async function (unit_id) {

  let unit = await Unit.findById(unit_id);

  if ((unit === null) || !unit.address_id.equals(this.address_id)) {
    return false;
  }

  return true;

}, "unit_id is not valid");

Appointment架构如下所示：

var AppointmentSchema = new mongoose.Schema(
  {
    member_id: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Member',
      required: true
    },
    client_id: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Client',
      required: true
    },
    address_id: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Address',
      required: true
    },
    unit_id: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Unit',
      required: true
    },
    dateAndTime: {
      type: Date,
      required: true
    }
  }
);

当我点击Express端点时，this.address_id未定义且我的验证无法正常工作。我的理解是，如果我将runValidators设置为true并context设置为'query'，我就可以获得此访问权限。

我做错了什么？

作为旁注，我还注意到Express在验证失败时返回200状态。这很奇怪。

感谢。