Broke descriminator model instance toObject() logic

[leviskay]

Use this plugin broke standart descriminator modle instance toObject logic, discriminator model fields don't fall in object, but accessible by dot.

const assert = require("assert");
const mongoose = require("mongoose");
const mongoRestActions = require("mongoose-rest-actions");

mongoose.plugin(mongoRestActions); // try to comment or not

const GITHUB_ISSUE = `gh6701`;
const connectionString = `mongodb://localhost:27017/${GITHUB_ISSUE}`;

run()
  .then(() => console.log("done"))
  .catch((error) => console.error(error.stack));

async function run() {
  await mongoose.connect(connectionString, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  });
  await mongoose.connection.dropDatabase();

  const membershipSchema = mongoose.Schema(
    {
      name: { type: String, required: true },
      price: { type: Number, required: true },
    },
    { discriminatorKey: "type" }
  );

  const subscriptionSchema = mongoose.Schema({
    frequency: {
      type: String,
      required: true,
    },
  });

  const Membership = mongoose.model("Membership", membershipSchema);
  const Subscription = Membership.discriminator(
    "Subscription",
    subscriptionSchema
  );

  await Subscription.create({
    name: "Monthly subscription",
    price: 1,
    frequency: "month",
  });

  const sub = await Membership.findOne({ price: 1 });

  console.log(sub); // don't have frequency field
  assert.equal(sub.frequency, "month"); // that's ok
}

Because of this it is not possible to send model-dependent field descriptor by express res.json() method