Using Modern Node.js Features

const res = await fetch("https://api.example.com/users", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({ name: "Ada" }),
  signal: AbortSignal.timeout(5000)
});
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const data = await res.json();

// index.mjs (or "type":"module")
const config = await loadConfig();
export { config };

import data from "./data.json" with { type: "json" };
// Older: with → assert (deprecated)
const mod = await import("./cfg.json", { with: { type: "json" } });

const stream = new ReadableStream({
  start(controller) { controller.enqueue("hi"); controller.close(); }
});
await fetch(url, { method: "POST", body: stream, duplex: "half" });

const ac = new AbortController();
setTimeout(() => ac.abort(new Error("timeout")), 1000);
await fetch(url, { signal: ac.signal });

// Helpers
AbortSignal.timeout(2000);
AbortSignal.any([sigA, sigB]);

const copy = structuredClone({
  date: new Date(),
  set: new Set([1, 2]),
  buf: new ArrayBuffer(8)
});

import { test } from "node:test";
import assert from "node:assert/strict";
test("greet", () => assert.equal(greet("Ada"), "hi Ada"));

const ws = new WebSocket("wss://echo.websocket.events");
ws.addEventListener("open", () => ws.send("hello"));
ws.addEventListener("message", (e) => console.log(e.data));