`deno serve`: support using the fetch handler as the default export

[pomdtr]

`deno serve`: support using the fetch handler as the default export

[pomdtr]

Currently deno serve expect the default export to be an object, with a fetch method:

export default {
  async fetch(request) {
    return new Response("Hello world!");
  },
};

I think exporting the fetch handler directly should also be supported.

export default async function(request) {
  return new Response("Hello world!");
}

[bartlomieju]

Can you explain a bit more what is the proposed convention here? Using any default export as a handler?