Cloudflare Workers - Hello world

helloworld.js

/*
An event listener for the FetchEvent tells the script to listen for any request coming to your Worker. 

The event handler is passed the event object, which includes event.request, a Request object 
which is a representation of the HTTP request that triggered the FetchEvent.
*/
addEventListener("fetch", event => {
 // The call to .respondWith() lets the Workers runtime intercept the request in order to send back a custom response.
 event.respondWith(handleRequest(event.request))
})

// custom function that receives as input the request object and returns a response object
async function handleRequest(request) {
  return new Response("Hello worker!", {
    headers: { "content-type": "text/plain" }
  })
}

/*
The request object is composed of:
 - body
 - cf (CF props https://developers.cloudflare.com/workers/runtime-apis/request#incomingrequestcfproperties)
 - headers
 - method
 - url
 
Demo for CF object https://developers.cloudflare.com/workers/examples/accessing-the-cloudflare-object
*/