use getPort in examples + tests

lib/pure/asynchttpserver.nim

@@ -15,20 +15,20 @@
 ## instead of allowing users to connect directly to this server.
 
 runnableExamples("-r:off"):
-  # This example will create an HTTP server on port 8080. The server will
-  # respond to all requests with a `200 OK` response code and "Hello World"
+  # This example will create an HTTP server on an automatically chosen port.
+  # It will respond to all requests with a `200 OK` response code and "Hello World"
   # as the response body.
   import std/asyncdispatch
   proc main {.async.} =
-    const port = 8080
     var server = newAsyncHttpServer()
     proc cb(req: Request) {.async.} =
       echo (req.reqMethod, req.url, req.headers)
       let headers = {"Content-type": "text/plain; charset=utf-8"}
       await req.respond(Http200, "Hello World", headers.newHttpHeaders())
 
-    echo "test this with: curl localhost:" & $port & "/"
-    server.listen(Port(port))
+    server.listen(Port(0)) # or Port(8080) to hardcode the standard HTTP port.
+    let port = server.getPort
+    echo "test this with: curl localhost:" & $port.uint16 & "/"
     while true:
       if server.shouldAcceptRequest():
         await server.acceptRequest(cb)

testament/lib/stdtest/netutils.nim

@@ -1,12 +1,13 @@
 import std/[nativesockets, asyncdispatch, os]
 
 proc bindAvailablePort*(handle: SocketHandle, port = Port(0)): Port =
+  ## See also `asynchttpserver.getPort`.
   block:
     var name: Sockaddr_in
     name.sin_family = typeof(name.sin_family)(toInt(AF_INET))
     name.sin_port = htons(uint16(port))
     name.sin_addr.s_addr = htonl(INADDR_ANY)
     if bindAddr(handle, cast[ptr SockAddr](addr(name)),
                 sizeof(name).Socklen) < 0'i32:
-      raiseOSError(osLastError())
+      raiseOSError(osLastError(), $port)
   result = getLocalAddr(handle, AF_INET)[1]

tests/stdlib/tasynchttpserver_transferencoding.nim

@@ -27,10 +27,9 @@ template genTest(input, expected) =
 
   let server = newAsyncHttpServer()
   waitFor runSleepLoop(server)
-  let port = getLocalAddr(server.getSocket.getFd, AF_INET)[1]
   let data = postBegin & input
   var socket = newSocket()
-  socket.connect("127.0.0.1", port)
+  socket.connect("127.0.0.1", server.getPort)
   socket.send(data)
   waitFor sleepAsync(10)
   socket.close()