set-headers

/** 
 * This service worker appends a header response for robots tag
 * Weird quirk where the content-type was maybe being erased.. didn't troubleshoot here, as I was only modifying pdf files.
*/

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

async function handleRequest(request) {
  const response = await fetch(request);

  // Clone the response so that it's no longer immutable 
  const {pathname} = new URL(request.url);
  const newResponse = new Response(response.body, response);

  // In this case, we are modifing the robots tag based on pathname .. 
  if (pathname.includes("indexifembedded")) {
    newResponse.headers.set('Content-Type','application/pdf');
    newResponse.headers.append('X-Robots-Tag','googlebot:noindex,indexifembedded');
    console.log('indexifembedded');
  };

  // In this case, we are modifing the robots tag based on different pathname .. 
  if (pathname.includes("noindexonly")) {
    newResponse.headers.set('Content-Type','application/pdf');
    newResponse.headers.append('X-Robots-Tag','googlebot:noindex');
    console.log('noindex');
  };

  return newResponse;
}