new worker

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

/**
 * Fetch and log a request
 * @param {Request} request
 */
async function handleRequest(request) {
  // Parse request URL to get access to query string
  let url = new URL(request.url);

  // Cloudflare-specific options are in the cf object.
  let options = { cf: { image: {} } }

  // Copy parameters from query string to request options.
  // You can implement various different parameters here.
  if (url.searchParams.has("fit")) options.cf.image.fit = url.searchParams.get("fit");
  if (url.searchParams.has("width")) options.cf.image.width = url.searchParams.get("width");
  if (url.searchParams.has("height")) options.cf.image.height = url.searchParams.get("height");
  if (url.searchParams.has("quality")) options.cf.image.quality = url.searchParams.get("quality");

  // Get URL of the original (full size) image to resize.
  // You could adjust the URL here, e.g. prefix it with a fixed address of your server,
  // so that user-visible URLs are shorter and cleaner.
  const imageURL = url.searchParams.get("image");

  // Build a request that passes through request headers,
  // so that automatic format negotiation can work.
  const imageRequest = new Request(imageURL, {
    headers: request.headers,
  });

  // Returning fetch() with resizing options will pass through response with the resized image.
  return fetch(imageRequest, options);
}