Handle funky 404s correctly

[GregBrimble]

In the event of a missing asset in KV (but where it is found in the manifest), we should probably just do default 404 behavior. Right now, we'll return a 500.

https://github.com/cloudflare/kv-asset-handler/blob/821dc0c45a9d750c4922c8bbece724df79dfa9b5/src/index.ts#L271 throws the error.

worker-sites-template/workers-site/index.js

Line 58 in dd042da

return new Response(e.message || e.toString(), { status: 500 })

will then return a 500 response.

[mhart]

I wonder too if it should check the error for status too, like: { status: e.status ?? 500 }

[mhart]

Looks like KVError uses status – not sure about others: https://github.com/cloudflare/kv-asset-handler/blob/821dc0c45a9d750c4922c8bbece724df79dfa9b5/src/types.ts#L19-L43