JavaScript OOP Design Patterns - Decorator Pattern

DecoratorPattern.js

//Decorator pattern
var Starbucks = (function () {
    var api = {};

    //Base function for creating beverages and condiments
    function Create ( product ) {
        function Product () {
            this._description = product || "";
            this._cost = 0.00;
        }

        //Base methods required for all descendents
        Product.prototype = {
            "setCost": function ( cost ) {
                this._cost = cost;
                return this;
            },
            "getCost": function () {
                return this._cost;
            },
            "setDescription": function ( desc ) {
                this._description = desc;
                return this;
            },
            "getDescription": function () {
                return this._description;
            }
        };

        return new Product();
    }

    /**Starbucks menu**/
    /**Beverages - these are the object to decorate**/
    var Latte = Create( "Latte" ).setCost( 1.50 ),
        Cappuccino = Create( "Cappuccino" ).setCost( 1.70 ),
        Mocha = Create( "Mocha" ).setCost( 1.60 ),
        Macchiato = Create( "Macchiato" ).setCost( 1.65 ),
        Tea = Create( "Tea" ).setCost( 1.20 );

    /**Condiments - these are the objects that beverages will be decorated with**/
    var Soya = Create( "Soya" ).setCost( 0.85 ),
        Milk = Create( "Milk" ).setCost( 0.65 ),
        AlmondMilk = Create( "Almond milk" ).setCost( 0.95 ),
        ChocolateSprinkles = Create( "Chocolate sprinkles" ).setCost( 0.15 ),
        Marshmellows = Create( "Mini marshmellows" ).setCost( 0.85 ),
        CinnamonSprinkles = Create( "Cinnamon sprinkles" ).setCost( 0.20 ),
        Sugar = Create( "Sugar" ).setCost( 0.35 );

    /**Cup Sizes*/
    var Small = Create( "Small" ).setCost( 0.69 ),
        Medium = Create( "Regular" ).setCost( 0.79 ),
        Large = Create( "Grande" ).setCost( 0.99 );

    /**Starbucks cashiers - behaviours**/
    var Cashier = function () {
        var cashier = {}, requestArray = [], customerRequestStr = "",
            customerRequest = [];//[SmallObj, MochaObj, SoyaObj, ...]
        /**private methods for the cashier to use*/
        function resetRequest () {
            customerRequest = [];
            customerRequestStr = "";
        }

        function getProduct ( product, index, req ) {
            switch ( product ) {
                case "Small":
                    customerRequest.push( Small );
                    break;
                case "Regular":
                    customerRequest.push( Medium );
                    break;
                case "Grande":
                    customerRequest.push( Large );
                    break;
                case "Latte":
                    customerRequest.push( Latte );
                    break;
                case "Cappuccino":
                    customerRequest.push( Cappuccino );
                    break;
                case "Mocha":
                    customerRequest.push( Mocha );
                    break;
                case "Macchiato":
                    customerRequest.push( Macchiato );
                    break;
                case "Tea":
                    customerRequest.push( Tea );
                    break;
                case "Soya":
                    customerRequest.push( Soya );
                    break;
                case "Milk":
                    customerRequest.push( Milk );
                    break;
                case "Almond milk":
                    customerRequest.push( AlmondMilk );
                    break;
                case "Chocolate sprinkles":
                    customerRequest.push( ChocolateSprinkles );
                    break;
                case "Mini marshmellows":
                    customerRequest.push( Marshmellows );
                    break;
                case "Cinnamon sprinkles":
                    customerRequest.push( CinnamonSprinkles );
                    break;
                case "Sugar":
                    customerRequest.push( Sugar );
                    break;
            }
        }

        function getCustomerRequest ( item, index, custArr ) {
            customerRequestStr += item.getDescription() + " ";
        }

        cashier.takeOrder = function ( req ) {//req -> ["Grande", "Mocha", ...]
            var requestArray = req;
            requestArray.forEach( getProduct );
            customerRequest.forEach( getCustomerRequest );
            return customerRequestStr.trim();
        };
        cashier.total = function () {
            var total = 0;

            function totalProducts ( product, index, arr ) {
                total += product.getCost();
            }

            customerRequest.forEach( totalProducts );
            /**Reset for next customer order**/
            resetRequest();
            return total;
        };
        return cashier;
    };
    /**Common behaviour of a Starbucks' customer*/
    var Customer = function () {
        function Customer () {
            this._customerRequest = [];
        }

        Customer.prototype = {
            "getRequest": function ( req ) {
                return this._customerRequest;
            },
            "request": function ( req ) {
                this._customerRequest = req;
                return this;
            }
        };
        return new Customer();
    };
    api.cashier = Cashier;
    api.customer = Customer;
    return api;
})();

//Starbucks employees - Mike and Marie
var MikeCashier = Starbucks.cashier(),
    MarieCashier = Starbucks.cashier();

//Starbucks customers - Joey, Anna and Ru
var Joey = Starbucks.customer(),
    Anna = Starbucks.customer(),
    Ru = Starbucks.customer();

Joey.request( [ "Small", "Mocha" ] );
Anna.request( [ "Regular", "Cappuccino" ] );
Ru.request( [ "Grande", "Mocha", "Milk", "Sugar" ] );

//Mike and Marie take Joey, Anna and Ru's request and tell them their total
console.log( MikeCashier.takeOrder( Joey.getRequest() ) );
console.log( MikeCashier.total() );

console.log( MarieCashier.takeOrder( Anna.getRequest() ) );
console.log( MarieCashier.total() );

console.log( MikeCashier.takeOrder( Ru.getRequest() ) );
console.log( MikeCashier.total() );