Fetching Next.js routes with Suspense

useDeliveryAddress.ts

import { use } from "react";
import type { DeliveryAddress } from "./types";

const cache = new Map<string, Promise<DeliveryAddress>>();

export function useDeliveryAddress(userId: string): DeliveryAddress {
  if (!cache.has(userId)) {
    const promise = fetch(`/api/user/delivery-address/${userId}`).then(
      (response) => {
        if (!response.ok) {
          throw new Error(`HTTP error! status: ${response.status}`);
        }
        return response.json();
      },
    );

    cache.set(userId, promise);
  }

  return use(cache.get(userId)!);
}