FWIW, you can work around it fairly easily by checking the status of the Response object returned from freshHandler:

const freshHandler = await createHandler(manifest, config);

Deno.serve(async (req, info) => {
  const { pathname } = new URL(req.url);

  if (pathname === "/special-route") {
    return new Response('special route');
  }

  const res = await freshHandler(req, info);

  if (res.status === 404) {
    return new Response('overridden 404 response', { status: 404 });
  }

  return res;
});

Only drawback is that the Fresh 404 page is still rendered (i.e. slight performance hit, and any side effects from rendering it will still happen).

Good idea! If the 404 page is empty, this shouldn't be too bad. Still, a way to opt out would be imo valuable.

@harrysolovay @lionel-rowe, what's the expected behavior here? I've modified RouterOptions so it looks like this:

export interface RouterOptions {
  trailingSlash?: boolean;
  ignoreFilePattern?: RegExp;
  disable404?: boolean;
}

So you can now use this (at least in my branch on my computer) to disable the 404 page. But what does that mean exactly? Right now I have this diff somewhere within the server code:

               async renderNotFound<Data = undefined>(data: Data) {
+                if (disable404) {
+                  throw new Deno.errors.NotFound();
+                }
                 return await renderNotFound(req, params, ctx, data);
               },

So if the flag is true, instead of running the renderNotFound handler, it will throw a not found error. Is this what you're looking for? I guess that error can then be caught and dealt with on your own.

Is this what you're looking for?

Yes.

I guess that error can then be caught and dealt with on your own.

This would be a fine solution, although returning undefined may be preferable imo.