CorsMiddleware returns 204 for preflight request

[sandorfr]

Looks like the current implementation of cors return a 204 for preflight request and it looks like Chrome considers any non-200 being a failure.
Doing some quick research on the web I've seen that there is discussions about what should be the good behavior but what I'm sure of is that we need that to just work.
Maybe we should be able to configure it?

[harshgMSFT]

204 is no content and is the right behavior for the middleware.chrome should display no content 😊 for this status code. Can you please post your request and response.

[danroth27]

Moved to aspnet/CORS#19.