Decorator Pattern in Typescript

decorator_pattern_typescript

abstract class Beverega { 
    abstract cost(): Number;
}

abstract class AddonDecorator extends Beverega { 
    public abstract cost(): Number;
}

class Expresso extends Beverega { 
    public cost(): Number { 
        return 1;
    }
}

class Caramel extends AddonDecorator { 
    constructor(private beverage: Beverega) { 
        super();
    }

    public cost(): Number { 
        return +this.beverage.cost() + 2;
    }
}

class Chocolate extends AddonDecorator { 
    constructor(private beverage: Beverega) { 
        super();
    }

    public cost(): Number { 
        return +this.beverage.cost() + 5;
    }
}

// Annonymous Test Class 
new class DecoratorPatternTests {
    constructor() {
        ( () => console.log(new Chocolate(new Caramel(new Expresso())).cost()) )();
    }
}();

// By Ythalo Rossy
// ythalorossy@gmail.com