flash: passing invalid as a response results in non-catchable errors and hangs

[kitsonk]

Something like the following:

Deno.serve(() => Promise.resolve(null), {
  onError(err) {
    console.log(err);
    return new Response("error", { status: 500 });
  }
});

Will result in:

TypeError: Cannot read properties of null (reading 'Symbol([[associated_ws]])')
    at Object.serve (deno:ext/flash/01_http.js:294:28)

And the onError() method won't be called, as expected.

I have a test in oak checking that bad responses are handled gracefully.

[brenelz]

I think this may be as simple as changing this:

// ext/flash/01_http.js
try {
  resp = await handler(req);
} catch (e) {
  resp = await onError(e);
}

to this:

// ext/flash/01_http.js
try {
  resp = await handler(req);
  if(!resp) {
    throw new Error('Invalid response');
  }
} catch (e) {
  resp = await onError(e);
}