Enabling Virtuals In Mongoose Lean Mode (in a FeathersJs service)

user.model.js

import mongooseLeanVirtuals from 'mongoose-lean-virtuals';

export default (app) => {
  const mongooseClient = app.get('mongooseClient');
  const {Schema} = mongooseClient;
  const {ObjectId} = Schema.Types;

  const user = new Schema({
    // ...
  });

  // Define a virtual attribute `UID`
  user.virtual('uid').get(function () {
    return this._id;
  });

  user.set('toObject', { virtuals: true });    // add this
  user.set('toJSON', { virtuals: true });      // add this

  user.plugin(mongooseLeanVirtuals);           // add this

  return mongooseClient.model('user', user);
};