is_broadcast.ts

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

async function handler(req: Request): Promise<Response> {
  if (typeof BroadcastChannel !== "undefined") {                              
    console.log("found broadcast channel");                                   
    return new Response("true");                                              
   }                                                                           
   return new Response("false");
}