feat: Enhance serverToSocket to enable different transformers on each socket pair

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 2.2.0
+
+- feat: Enhance serverToSocket adding optional parameter `beforeJoining` which
+  will be called before a socket pair is actually joined together. Thus,
+  different transformers can be used for each socket pair.
+
 ## 2.1.0
 - Added `multi` parameter to `SocketConnector.serverToSocket` - whether to
   create new connections on the "B" side every time there is a new "A" side

lib/src/socket_connector.dart

@@ -386,6 +386,12 @@ class SocketConnector {
   ///   to the bound server port [portA]
   /// - [onConnect] is called when [portA] has got a new connection and a
   ///   corresponding outbound socket has been created to [addressB]:[portB]
+  ///   and the two have been joined together
+  /// - [beforeJoining] is called when [portA] has got a new connection and a
+  ///   corresponding outbound socket has been created to [addressB]:[portB]
+  ///   but **before** they are joined together. This allows the code which
+  ///   called [serverToSocket] to take additional steps (such as setting new
+  ///   transformers rather than the ones which were provided initially)
   static Future<SocketConnector> serverToSocket(
       {
       /// Defaults to [InternetAddress.anyIPv4]
@@ -400,7 +406,9 @@ class SocketConnector {
       Duration timeout = SocketConnector.defaultTimeout,
       IOSink? logger,
       bool multi = false,
-      Function(Socket sideA, Socket sideB)? onConnect}) async {
+      @Deprecated("use beforeJoining instead")
+      Function(Socket socketA, Socket socketB)? onConnect,
+      Function(Side sideA, Side sideB)? beforeJoining}) async {
     IOSink logSink = logger ?? stderr;
     addressA ??= InternetAddress.anyIPv4;
 
@@ -428,6 +436,7 @@ class SocketConnector {
       // connect to the side 'B' address and port
       Socket sideBSocket = await Socket.connect(addressB, portB);
       Side sideB = Side(sideBSocket, false, transformer: transformBtoA);
+      beforeJoining?.call(sideA, sideB);
       unawaited(connector.handleSingleConnection(sideB));
 
       onConnect?.call(sideASocket, sideBSocket);

pubspec.yaml

@@ -1,7 +1,7 @@
 name: socket_connector
 description: Package for joining sockets together to create socket relays.
 
-version: 2.1.0
+version: 2.2.0
 repository: https://github.com/cconstab/socket_connector
 
 environment:

test/socket_connector_test.dart

@@ -312,9 +312,11 @@ void main() {
           verbose: true,
           timeout: Duration(milliseconds: 100),
           multi: true,
-          onConnect: (Socket sideA, Socket sideB) {
+          beforeJoining: (Side sideA, Side sideB) {
             serverConnections++;
             print('SocketConnector.serverToSocket onConnect called back');
+            sideA.transformer = aToB;
+            sideB.transformer = bToA;
           });
       expect(connector.connections.isEmpty, true);
 
@@ -357,14 +359,14 @@ void main() {
         // Wait for the sockets to send and receive data
         await Future.delayed(Duration(milliseconds: 10));
 
-        socketA.write('hello world from side A');
+        socketA.write('hello world');
         expect(currentSocketB != null, true);
-        currentSocketB?.write('hello world from side B');
+        currentSocketB?.write('hello world');
         // Wait for the sockets to send and receive data
         await Future.delayed(Duration(milliseconds: 10));
 
-        expect(rcvdA.last, "${aSockets.length}: hello world from side B");
-        expect(rcvdB.last, "${bSockets.length}: hello world from side A");
+        expect(rcvdA.last, "${aSockets.length}: from B: hello world");
+        expect(rcvdB.last, "${bSockets.length}: from A: hello world");
         expect(rcvdA.length, i + 1);
         expect(rcvdB.length, i + 1);
       }