Add resolveTAddress(string, Port) and test for it.

asyncdispatch2/transports/common.nim

@@ -194,6 +194,31 @@ proc resolveTAddress*(address: string,
         it = it.ai_next
       freeAddrInfo(aiList)
 
+proc resolveTAddress*(address: string, port: Port,
+                      family = IpAddressFamily.IPv4): seq[TransportAddress] =
+  ## Resolve string representation of ``address``.
+  ## 
+  ## ``address`` could be dot IPv4/IPv6 address or hostname.
+  ## 
+  ## If hostname address is detected, then network address translation via DNS
+  ## will be performed.
+  var ta: TransportAddress
+  result = newSeq[TransportAddress]()
+  if isIpAddress(address):
+    ta = TransportAddress(address: parseIpAddress(address), port: port)
+    result.add(ta)
+  else:
+    var domain = if family == IpAddressFamily.IPv4: Domain(AF_INET) else:
+                   Domain(AF_INET6)
+    var aiList = getAddrInfo(address, port, domain)
+    var it = aiList
+    while it != nil:
+      fromSockAddr(cast[ptr Sockaddr_storage](it.ai_addr)[],
+                   SockLen(it.ai_addrlen), ta.address, ta.port)
+      result.add(ta)
+      it = it.ai_next
+    freeAddrInfo(aiList)
+
 template checkClosed*(t: untyped) =
   if (ReadClosed in (t).state) or (WriteClosed in (t).state):
     raise newException(TransportError, "Transport is already closed!")

tests/testaddress.nim

@@ -57,3 +57,36 @@ when isMainModule:
       for item in hostnames:
         var taseq = resolveTAddress(item)
         check len(taseq) >= 1
+    test "resolveTAddress(string, Port)":
+      var numeric4 = [
+        "0.0.0.0",
+        "255.0.0.255",
+        "128.128.128.128",
+        "255.255.255.255"
+      ]
+
+      var numeric6 = [
+        "::",
+        "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff",
+        "aaaa:bbbb:cccc:dddd:eeee:ffff::1111",
+        "aaaa:bbbb:cccc:dddd:eeee:ffff::",
+        "a:b:c:d:e:f::",
+        "2222:3333:4444:5555:6666:7777:8888:9999"
+      ]
+      var hostnames = [
+        "www.google.com",
+        "www.github.com"
+      ]
+      for item in numeric4:
+        var taseq = resolveTAddress(item, Port(443))
+        check len(taseq) == 1
+        check $taseq[0] == item & ":443"
+
+      for item in numeric6:
+        var taseq = resolveTAddress(item, Port(443))
+        check len(taseq) == 1
+        check $taseq[0] == "[" & item & "]" & ":443"
+
+      for item in hostnames:
+        var taseq = resolveTAddress(item, Port(443))
+        check len(taseq) >= 1