Comment by franciscop

I've been following Bunny (BunnyCDN/Bunny.net) for a while and love what they are doing. Couple of suggestions:

• Every code snippet should be copy/pasteable (and work well), that article might be the entry point to what many are doing.

• I have this feeling this is following Cloudflare's Workers style of `addEventListener('fetch', eventHandler);`. I need to write a 500-word essay on that, but the short version is that I strongly believe that it'd be way better for their clients if the client could just do `export default async function handleDns(event) { ... }` instead of having a global (what?) context where there's a function unattached called `addEventListener` and you need to know it's for `"dns"` (is there even other possibility here?) and that the respondWith() only accepts a promise, which is not common (it's more common to accept an async fn which then becomes a promise). Compare these two snippets, current and with my small proposal:

    // Current API:
    addEventListener('dns', event => {
      event.respondWith(handleRequest(event.request));
    });

    function handleRequest(request) {
      return new TxtRecord('Hello world!, 30);
    }

    vs

    // Potential/suggested API:
    export default function handleDns(event) {
      return new TxtRecord('Hello world!, 30);
    }

This way it's easier to write, to reason about, to test, etc. It's all advantages from the client point of view, and I understand it's slightly more code from Bunny's point of view but it could be done fairly trivially on Bunny's end; they could just wrap the default export with this code on their infra level, simplifying and making dev lives a lot easier:

    // Wrapper.js
    import handler from './user-fn.js';

    addEventListener('dns', event => {
      if (typeof handler === 'function') {
        event.respondWith(handler(event));
      } else {
        // Could support other basic types here, like
        // exporting a plain TxtRecord('Hello', 30);
        throw new Error('Only handler functions supported now');
      }
    });