Core worker code for url-forwarder based on Cloudflare Worker-KV

url-forwarder-worker-cloudflare.js

// This is the companion code for the linked blog 
// https://blog.kmonsoor.com/on-edge-shortlink-server-cloudflare-kv-worker
// Please check the blog to get the context
// author : Khaled Monsoor (@kmonsoor)
// last updated: 25-May-2021

const failsafeURL = "https://kmonsoor.com"  // replace it with yours ;)
const defaultStatusCode = 301               // standard HTTP code for redirection, don't change

addEventListener("fetch", (event) => {
  event.respondWith(handleRequest(event.request));
});

async function handleRequest(request) {
  // console.log(request);
  const requestURL = new URL(request.url);

  if (requestURL.pathname === '/')
      return Response.redirect(failsafeURL, defaultStatusCode);

  const keySource = requestURL.pathname.substring(1);
  // console.log(keySource);
  const destinationURL = await GO_REDIRECTS.get(keySource);
  // console.log(destinationURL);

  if (destinationURL === null) {
    // the message below can be updated as per your audience
    return new Response("We couldn't find any such page", {status: 404})
  }
  else return Response.redirect(destinationURL, defaultStatusCode);
};