composite pattern

structure_patterns/Composite.ts

@@ -0,0 +1,48 @@
+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))