Composite.js

class Equipment
{
    getPrice()
    {
        return this.price || 0;
    }
    
    getName()
    {
        return this.name;
    }
    
    setName(name)
    {
        this.name = name;
    }
    
    setPrice(price)
    {
        this.price = price;
    }
}

class Engine extends Equipment
{
    constructor()
    {
        super();
        this.setName('Engine');
        this.setPrice(800);
    }
}

class Body extends Equipment
{
    constructor()
    {
        super();
        this.setName('Body');
        this.setPrice(3000);
    }
}

class Tools extends Equipment
{
    constructor()
    {
        super();
        this.setName('Tools');
        this.setPrice(4000);
    }
}

class Composite extends Equipment
{
    constructor()
    {
        super();
        this.equipments = [];
    }
    
    add(equipment)
    {
        this.equipments.push(equipment);
    }
    
    getPrice()
    {
        return this.equipments
                .map(equipment => equipment.getPrice())
                .reduce((a,b) => a+b);
    }
}

class Car extends Composite
{
    constructor()
    {
        super();
        this.setName('Audi');
    }
}

const myCar = new Car();

myCar.add(new Engine());
myCar.add(new Body());
myCar.add(new Tools());

console.log(`${myCar.getName()} price is ${myCar.getPrice()}$`);