Handling Asynchronous Operations

import fs from "node:fs";
fs.readFile("a.txt", "utf8", (err, data) => {
  if (err) return console.error(err);
  console.log(data);
});

fetch("/api").then((r) => r.json()).then(console.log).catch(console.error);

async function loadUser(id) {
  try {
    const res = await fetch(`/users/${id}`);
    if (!res.ok) throw new Error(res.statusText);
    return await res.json();
  } catch (err) { console.error("loadUser failed", err); throw err; }
}

import { promisify } from "node:util";
import fs from "node:fs";
const readFile = promisify(fs.readFile);
const data = await readFile("a.txt", "utf8");

const [user, posts] = await Promise.all([fetchUser(id), fetchPosts(id)]);

const results = await Promise.allSettled(urls.map((u) => fetch(u)));
const ok = results.filter((r) => r.status === "fulfilled");

const ctrl = new AbortController();
setTimeout(() => ctrl.abort(), 5000);
const res = await fetch(url, { signal: ctrl.signal });