How to properly export an ES6 class in Node 4?

// person.js'use strict';module.exports = class Person {   constructor(firstName, lastName) {       this.firstName = firstName;       this.lastName = lastName;   }   display() {       console.log(this.firstName + " " + this.lastName);   }}

// index.js'use strict';var Person = require('./person.js');var someone = new Person("First name", "Last name");someone.display();

If you are using ES6 in Node 4, you cannot use ES6 module syntax without a transpiler, but CommonJS modules (Node's standard modules) work the same.

module.export.AspectType

should be

module.exports.AspectType

hence the error message "Cannot set property 'AspectType' of undefined" because module.export === undefined.

Also, for

var AspectType = class AspectType {    // ...    };

can you just write

class AspectType {    // ...    }

and get essentially the same behavior.

With ECMAScript 2015 you can export and import multiple classes like this

class Person{    constructor()    {        this.type = "Person";    }}class Animal{    constructor()    {        this.type = "Animal";    }}module.exports = {    Person,    Animal};

then where you use them:

const { Animal, Person } = require("classes");const animal = new Animal();const person = new Person();

In case of name collisions, or you prefer other names you can rename them like this:

const { Animal : OtherAnimal, Person : OtherPerson} = require("./classes");const animal = new OtherAnimal();const person = new OtherPerson();