Before
checkout.ts
export async function checkout(cart: Cart) {
  if (cart.items.length === 0) {
    return { status: "empty", total: 0 };
  }

  const total = cart.items.reduce((sum, item) => {
    return sum + item.price * item.quantity;
  }, 0);

  return { status: "ready", total };
}
After
checkout.ts
export async function checkout(cart: Cart) {
  const total = cart.items.reduce((sum, item) => {
    return sum + item.price * item.quantity;
  }, 0);

  return {
    status: cart.items.length > 0 ? "ready" : "empty",
    total,
  };
}