Add hasDataBuffered to asyncnet (#16000)

Co-authored-by: flywind <xzsflywind@gmail.com>
Co-authored-by: Timothee Cour <timothee.cour2@gmail.com>

changelog.md

@@ -246,6 +246,8 @@
 
 - Added dollar `$` and `len` for `jsre.RegExp`.
 
+- Added `hasDataBuffered` to `asyncnet`.
+
 - Added `hasClosure` to `std/typetraits`.
 
 

lib/pure/asyncnet.nim

@@ -650,6 +650,11 @@ proc bindAddr*(socket: AsyncSocket, port = Port(0), address = "") {.
     raiseOSError(osLastError())
   freeaddrinfo(aiList)
 
+proc hasDataBuffered*(s: AsyncSocket): bool {.since: (1, 5).} =
+  ## Determines whether an AsyncSocket has data buffered.
+  # xxx dedup with std/net
+  s.isBuffered and s.bufLen > 0 and s.currPos != s.bufLen
+
 when defined(posix):
 
   proc connectUnix*(socket: AsyncSocket, path: string): owned(Future[void]) =