Async Wrapper Function & JSON Fetch Handler

utils.ts

// Based on https://www.maxpou.fr/async-await-without-try-catch and https://github.com/DavidWells/safe-await/pull/2/files
export function wrapAsyncFn<T>(somePromise: Promise<T>) {
	return somePromise.then((data) => [null, data]).catch((err) => [err, null]);
}

// Based on https://www.youtube.com/watch?v=aIboXjxo-w8
export async function fetchJson(
	input: RequestInfo,
	init?: RequestInit | undefined,
) {
	const [error, response] = await wrapAsyncFn(fetch(input, init));

	if (error) {
		return [undefined, "Server error"];
	}

	const contentType = response?.headers?.get("content-type");

	if (!response.ok || !contentType.includes("application/json")) {
		return [undefined, "Server error"];
	}

	const json = await response.json();
	return [json, undefined];
}