export async function jsonFetcher(url: string): Promise { const res = await fetch(url); if (!res.ok) { if (res.status === 404) { return null; } const error = new Error("An error occurred while fetching the data."); throw error; } return res.json(); }; export async function jsonFetcherWithLastModified(url: string): Promise<{ data: T, lastModified: string | null } | null> { const res = await fetch(url); if (!res.ok) { if (res.status === 404) { return null; } const error = new Error("An error occurred while fetching the data."); throw error; } return { lastModified: res.headers.get("Last-Modified"), data: await res.json(), }; } export async function csvFetcher(url: string): Promise { return (await fetch(url)).text(); }