JavaScript OOP in NodeJS: how?

Question

I am used to the classical OOP as in Java.

What are the best practices to do OOP in JavaScript using NodeJS?

Each Class is a file with module.export?

How to create Classes?

this.Class = function() {
    //constructor?
    var privateField = ""
    this.publicField = ""
    var privateMethod = function() {}
    this.publicMethod = function() {} 
}

vs. (I am not even sure it is correct)

this.Class = {
    privateField: ""
    , privateMethod: function() {}

    , return {
        publicField: ""
        publicMethod: function() {}
    }
}

vs.

this.Class = function() {}

this.Class.prototype.method = function(){}

...

How would inheritance work?

Are there specific modules for implementing OOP in NodeJS?

I am finding a thousand different ways to create things that resemble OOP.. but I have no clue what is the most used/practical/clean way.

Bonus question: what is the suggested "OOP style" to use with MongooseJS? (can a MongooseJS document be seen as a Class and a model used as an instance?)

EDIT

here is an example in JsFiddle please provide feedback.

//http://javascriptissexy.com/oop-in-javascript-what-you-need-to-know/
function inheritPrototype(childObject, parentObject) {
    var copyOfParent = Object.create(parentObject.prototype)
    copyOfParent.constructor = childObject
    childObject.prototype = copyOfParent
}

//example
function Canvas (id) {
    this.id = id
    this.shapes = {} //instead of array?
    console.log("Canvas constructor called "+id)
}
Canvas.prototype = {
    constructor: Canvas
    , getId: function() {
        return this.id
    }
    , getShape: function(shapeId) {
        return this.shapes[shapeId]
    }
    , getShapes: function() {
        return this.shapes
    }
    , addShape: function (shape)  {
        this.shapes[shape.getId()] = shape
    }
    , removeShape: function (shapeId)  {
        var shape = this.shapes[shapeId]
        if (shape)
            delete this.shapes[shapeId]
        return shape
    }
}

function Shape(id) {
    this.id = id
    this.size = { width: 0, height: 0 }
    console.log("Shape constructor called "+id)
}
Shape.prototype = {
    constructor: Shape
    , getId: function() {
        return this.id
    }
    , getSize: function() {
        return this.size
    }
    , setSize: function (size)  {
        this.size = size
    }
}

//inheritance
function Square(id, otherSuff) {
    Shape.call(this, id) //same as Shape.prototype.constructor.apply( this, arguments ); ?
    this.stuff = otherSuff
    console.log("Square constructor called "+id)
}
inheritPrototype(Square, Shape)
Square.prototype.getSize = function() { //override
    return this.size.width
}

function ComplexShape(id) {
    Shape.call(this, id)
    this.frame = null
    console.log("ComplexShape constructor called "+id)
}
inheritPrototype(ComplexShape, Shape)
ComplexShape.prototype.getFrame = function() {
    return this.frame
}
ComplexShape.prototype.setFrame = function(frame) {
    this.frame = frame
}

function Frame(id) {
    this.id = id
    this.length = 0
}
Frame.prototype = {
    constructor: Frame
    , getId: function() {
        return this.id
    }
    , getLength: function() {
        return this.length
    }
    , setLength: function (length)  {
        this.length = length
    }
}

/////run
var aCanvas = new Canvas("c1")
var anotherCanvas = new Canvas("c2")
console.log("aCanvas: "+ aCanvas.getId())

var aSquare = new Square("s1", {})
aSquare.setSize({ width: 100, height: 100})
console.log("square overridden size: "+aSquare.getSize())

var aComplexShape = new ComplexShape("supercomplex")
var aFrame = new Frame("f1")
aComplexShape.setFrame(aFrame)
console.log(aComplexShape.getFrame())

aCanvas.addShape(aSquare)
aCanvas.addShape(aComplexShape)
console.log("Shapes in aCanvas: "+Object.keys(aCanvas.getShapes()).length)

anotherCanvas.addShape(aCanvas.removeShape("supercomplex"))
console.log("Shapes in aCanvas: "+Object.keys(aCanvas.getShapes()).length)
console.log("Shapes in anotherCanvas: "+Object.keys(anotherCanvas.getShapes()).length)

console.log(aSquare instanceof Shape)
console.log(aComplexShape instanceof Shape)

Answer 1

This is an example that works out of the box. If you want less "hacky", you should use inheritance library or such.

Well in a file animal.js you would write:

var method = Animal.prototype;

function Animal(age) {
    this._age = age;
}

method.getAge = function() {
    return this._age;
};

module.exports = Animal;

To use it in other file:

var Animal = require("./animal.js");

var john = new Animal(3);

If you want a "sub class" then inside mouse.js:

var _super = require("./animal.js").prototype,
    method = Mouse.prototype = Object.create( _super );

method.constructor = Mouse;

function Mouse() {
    _super.constructor.apply( this, arguments );
}
//Pointless override to show super calls
//note that for performance (e.g. inlining the below is impossible)
//you should do
//method.$getAge = _super.getAge;
//and then use this.$getAge() instead of super()
method.getAge = function() {
    return _super.getAge.call(this);
};

module.exports = Mouse;

Also you can consider "Method borrowing" instead of vertical inheritance. You don't need to inherit from a "class" to use its method on your class. For instance:

 var method = List.prototype;
 function List() {

 }

 method.add = Array.prototype.push;

 ...

 var a = new List();
 a.add(3);
 console.log(a[0]) //3;