Node.js Routing and JSON APIs

const http = require("http");

const items = [{ id: 1, name: "Notebook" }];

const server = http.createServer((req, res) => {
  const send = (status, data) => {
    res.writeHead(status, { "Content-Type": "application/json" });
    res.end(JSON.stringify(data));
  };
  if (req.method === "GET" && req.url === "/items") return send(200, items);
  if (req.method === "POST" && req.url === "/items") {
    let body = "";
    req.on("data", (c) => (body += c));
    req.on("end", () => {
      const item = { id: items.length + 1, ...JSON.parse(body) };
      items.push(item);
      send(201, item);
    });
    return;
  }
  send(404, { error: "not found" });
});

server.listen(0, async () => {
  const base = `http://localhost:${server.address().port}`;
  const created = await fetch(base + "/items", { method: "POST", body: JSON.stringify({ name: "Pen" }) });
  console.log(created.status, await created.json());
  const list = await fetch(base + "/items");
  console.log(list.status, (await list.json()).map((i) => i.name));
  const missing = await fetch(base + "/nope");
  console.log(missing.status);
  server.close();
});

201 { id: 2, name: 'Pen' }
200 [ 'Notebook', 'Pen' ]
404