checkRedirects.js

const puppeteer = require("puppeteer");
const readline = require("readline");

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  terminal: false
});

const eq = (a, b) => {
  const _a = new URL(a);
  const _b = new URL(b);
  return _a.host === _b.host;
};

const getUrls = async rl => {
  const urls = [];
  for await (const url of rl) {
    urls.push(url);
  }
  return urls;
};

const checkRedirect = browser => async url => {
  try {
    const page = await browser.newPage();
    const response = await page.goto(url);

    eq(url, response.url()) === false &&
      console.log(`${url} redirects to ${response.url()}`);
  } catch (e) {
    console.error(`Failed to check ${url}`);
  }
};

const main = async rli => {
  const urls = await getUrls(rli);
  console.log(`Checking ${urls.length} URL${urls.length === 1 ? "" : "s"}`);
  const browser = await puppeteer.launch({ ignoreHTTPSErrors: true });

  await Promise.all(urls.map(checkRedirect(browser)));
  browser.close();
};

main(rl).then(() => process.exit(0));