Mongoose cannot register a global plugin on runtime

[vorillaz]

Do you want to request a feature or report a bug?
I think it's a bug

What is the current behavior?
I am trying to register a global plugin within a closure with not

If the current behaviour is a bug, please provide the steps to reproduce.
I am trying to bootstrap mongoose with a simple Express.js app. My app sets up a few dependencies and I am trying to pass a global plugin for mongoose within a closure. The console.log does not work at all and the methods are missing from my schemas.

const mongoose = require('mongoose');

const config = {};
const {DB_CONNECT} = process.env;

const myPlugin = schema => {
  console.log('done'); // this line is not executed
  schema.methods.mymethod = () => {};
}

const connectAndAddPlugins = async () => {
  await mongoose.connect(
    DB_CONNECT,
    {...config}
  );
  mongoose.plugin(myPlugin)
};

connectAndAddPlugins();

What is the expected behavior?
mymethod shall be present to my internal models.

Please mention your node.js, mongoose and MongoDB version.
node.js: v9.3.0
mongoose: ^5.2.13
MongoDB: v4.0.2

[vorillaz]

Apparently, since mongoose compiles the first model global plugins are not applied any more.