Node generate a bitly shortened url link

bitly.js

#!/usr/local/bin/node
const https = require("https");
const TOKEN = "YOUR_BITLY_TOKEN";

// get the script input variable from KBM otherwise use proces.argv.slice(2)[0] instead
const getStdIn = async () => {
  let result = '';
  process.stdin.setEncoding('utf8');

  for await (const chunk of process.stdin) {
    result += chunk;
  }

  return result;
};

const shortUrl = (url) => {
  const payload = JSON.stringify({ "long_url": url });
  const options = {
    hostname: "api-ssl.bitly.com",
    path: "/v4/bitlinks",
    method: "POST",
    headers: {
      "Authorization": `Bearer ${TOKEN}`,
      "Content-Type": "application/json",
      "Content-Length": Buffer.byteLength(payload),
    },
  };

  return new Promise((resolve, reject) => {
    https.request(options, (res) => {
      let body = "";
      res.on("data", (chunk) => body += chunk);
      res.on("end", () => {
        if (res.statusCode >= 400) {
          reject(body);
        } else {
          resolve(JSON.parse(body));
        }
      });
    }).write(payload);
  });
};

(async function() {
  try {
    const url = await getStdIn(); // or use process argv - see function definition.
    const result = await shortUrl(url);
    process.stdout.write(result.link);
  } catch (error) {
    process.stderr.write(error);
  }
}());