Checkout workflow

type OrderRequest = {
  orderId: string;
  sku: string;
  quantity: number;
  paymentToken: string;
};

class InventoryService {
  reserve(sku: string, quantity: number) {
    console.log(`Reserved ${quantity} of ${sku}`);
  }
}

class PaymentService {
  charge(paymentToken: string) {
    console.log(`Charged payment token ${paymentToken}`);
  }
}

class ShipmentService {
  createShipment(orderId: string) {
    console.log(`Created shipment for ${orderId}`);
  }
}

class CheckoutFacade {
  constructor(
    private readonly inventory: InventoryService,
    private readonly payments: PaymentService,
    private readonly shipments: ShipmentService,
  ) {}

  placeOrder(request: OrderRequest) {
    this.inventory.reserve(request.sku, request.quantity);
    this.payments.charge(request.paymentToken);
    this.shipments.createShipment(request.orderId);
  }
}

const checkout = new CheckoutFacade(
  new InventoryService(),
  new PaymentService(),
  new ShipmentService(),
);

checkout.placeOrder({
  orderId: "order-123",
  sku: "keyboard",
  quantity: 1,
  paymentToken: "token_abc",
});