Composite.ts

abstract class DeliveryItem {
	items: DeliveryItem[]

	addItem(item: DeliveryItem) {
		this.items.push(item)
	}

	getItemPrices(): number {
		return this.items.reduce((acc: number, i: DeliveryItem) => acc += i.getItemPrices(), 0)
	}

	abstract getPrice(): number
}

class DeliveryShop extends DeliveryItem {
	constructor(private delivaryFee: number) {
		super()
	}

	getPrice(): number {
		return this.items.reduce((acc: number, i: DeliveryItem) => acc += i.getItemPrices(), 0) + this.delivaryFee
	}
}

class Package extends DeliveryItem {s
	getPrice(): number {
		return this.getItemPrices()
	}
}

class Product extends DeliveryItem {
	constructor(private price: number) {
		super()
	}

	getPrice(): number {
		return this.price
	}
}

const shop = new DeliveryShop(100)
shop.addItem(new Product(1000))
const pack1 = new Package()
pack1.addItem(new Product(200))
pack1.addItem(new Product(300))
shop.addItem(pack1)
const pack2 = new Package()
pack2.addItem(new Product(30))