Body used detection not working

[zefir-git]

Request.incomingMessage passes the IncomingMessage instance itself for bodyStream; because of that, Request#bodyStream.readableDidRead is always true in Request#bodyUsed() since at this point reading the request itself (not specifically body) has started.

I don’t think stream.Readable exposes any API to determine if already read. However, IncomingMessage has #complete which indicates whether the request has been fully read.