I've create a Mongoose model and I wrote some code to test if it works, I tried to save the model and then display all of the models but it doesn't log anything to the console and the model isn't saving.
My testing code:
let User = require('./models/user')(MAI);
let myUser = new User({
  username: 'Admin',
  email: 'admin@example.com',
  password: '123456',
});
await myUser.save();
User.find((err, users) => {
  if(err) console.log(err);
  console.dir(users);
});
My model:
const mongoose = require('mongoose');
const UserSchema = mongoose.Schema({
  user_id: Number,
  username: String,
  email: String,
  password: String,
  verified: { type: Boolean, default: false },
  joindate: { type: Date, default: Date.now },
  postcount: { type: Number, default: 0 },
});
module.exports = function(MAI) {
  UserSchema.plugin(MAI.plugin, {
    model: 'User',
    field: 'user_id',
    startAt: 1,
    incrementBy: 1,
    unique: true
  });
  return mongoose.model('User', UserSchema);
}
And if it's important, mongoose & mai initialization:
mongoose.Promise = require('bluebird');
let connection = mongoose.createConnection('mongodb://localhost:27017/forum');
MAI.initialize(connection);