decorator_classic_oop_pattern_part_1.3.js

/**
 * ConcreteComponent
 * (класс для последующего декорирования)
 */
class Coffee {
	private cost :number = 1;

	getCost() :number {
		return this.cost;
	}
}

/**
 * Decorator A
 */
function milkDecorator() :void {
	this.cost += 0.5;
}

/**
 * Decorator B
 */
function whipDecorator() :void {
	this.cost += 0.7;
}

/**
 * Decorator C
 */
function sprinklesDecorator() :void {
	this.cost += 0.2;
}

function decorate<T>(...args) :T {
	let target = args.shift();
	args.map((decor) => decor.apply(target));
	return target;
}

var coffee = new Coffee();
var myCoffee = decorate<Coffee>(
	coffee,
	milkDecorator,
	whipDecorator,
	sprinklesDecorator
);

console.log(myCoffee.getCost());