allow empty protocol string in dial

libp2p/switch.nim

@@ -206,30 +206,30 @@ proc dial*(s: Switch,
            Future[Connection] {.async.} =
   let id = peer.id
   trace "Dialing peer", peer = id
-  result = s.connections.getOrDefault(id)
-  if result.isNil or result.closed:
+  var conn = s.connections.getOrDefault(id)
+  if conn.isNil or conn.closed:
     for t in s.transports: # for each transport
       for a in peer.addrs: # for each address
         if t.handles(a):   # check if it can dial it
           trace "Dialing address", address = $a
-          result = await t.dial(a)
+          conn = await t.dial(a)
           # make sure to assign the peer to the connection
-          result.peerInfo = peer
-          result = await s.upgradeOutgoing(result)
-          if isNil(result):
+          conn.peerInfo = peer
+          conn = await s.upgradeOutgoing(conn)
+          if isNil(conn):
             continue
 
-          result.closeEvent.wait()
+          conn.closeEvent.wait()
             .addCallback do (udata: pointer):
-              asyncCheck s.cleanupConn(result)
+              asyncCheck s.cleanupConn(conn)
           break
   else:
     trace "Reusing existing connection"
 
-  if isNil(result):
-    raise newException(CatchableError, "unable to establish outgoing link!")
+  if isNil(conn):
+    raise newException(CatchableError, "Unable to establish outgoing link")
 
-  if proto.len > 0 and not result.closed:
+  if proto.len > 0 and not conn.closed:
     let stream = await s.getMuxedStream(peer)
     if not isNil(stream):
       trace "Connection is muxed, return muxed stream"

tests/testswitch.nim

@@ -34,9 +34,7 @@ method init(p: TestProto) {.gcsafe.} =
   p.codec = TestCodec
   p.handler = handle
 
-suite "Switch":
-  test "e2e use switch":
-    proc createSwitch(ma: MultiAddress): (Switch, PeerInfo) {.gcsafe.}=
+proc createSwitch(ma: MultiAddress): (Switch, PeerInfo) =
   let seckey = PrivateKey.random(RSA)
   var peerInfo: PeerInfo = PeerInfo.init(PrivateKey.random(RSA))
   peerInfo.addrs.add(ma)
@@ -56,6 +54,8 @@ suite "Switch":
                           secureManagers)
   result = (switch, peerInfo)
 
+suite "Switch":
+  test "e2e use switch dial proto string":
     proc testSwitch(): Future[bool] {.async, gcsafe.} =
       let ma1: MultiAddress = Multiaddress.init("/ip4/0.0.0.0/tcp/0")
       let ma2: MultiAddress = Multiaddress.init("/ip4/0.0.0.0/tcp/0")
@@ -82,3 +82,24 @@ suite "Switch":
 
     check:
       waitFor(testSwitch()) == true
+
+  test "e2e use switch no proto string":
+    proc testSwitch(): Future[bool] {.async, gcsafe.} =
+      let ma1: MultiAddress = Multiaddress.init("/ip4/0.0.0.0/tcp/0")
+      let ma2: MultiAddress = Multiaddress.init("/ip4/0.0.0.0/tcp/0")
+
+      var peerInfo1, peerInfo2: PeerInfo
+      var switch1, switch2: Switch
+      (switch1, peerInfo1) = createSwitch(ma1)
+      asyncCheck switch1.start()
+
+      (switch2, peerInfo2) = createSwitch(ma2)
+      asyncCheck switch2.start()
+      var conn = await switch2.dial(switch1.peerInfo)
+
+      check isNil(conn)
+      discard allFutures(switch1.stop(), switch2.stop())
+      result = true
+
+    check:
+      waitFor(testSwitch()) == true