Example ES6 class

greeter.js

import Etiquette from './lib/etiquette';
import message from './lib/message';

class Greeter extends Etiquette {

    constructor (config) {
        super();

        this.intro = config.intro;
        this.name = config.name;
    }

    message (greeting) {
        console.log(`${greeting} ${this.name}`);
    }

    async hello () {
        const greeting = await message.waitUntilArrive();
        this.message(greeting);
    }

    async goodbye () {
        const farewell = await message.waitUntilExit();
        this.message(farewell);
    }
}

const example = new Greeter({
    intro: 'Hello',
    name: 'Colin Rotherham'
});

try {
    example.hello();
    example.goodbye();

} catch (err) {
    console.err(err);
}