test: add a couple of simple programmes to help with testing where we…

… want to shove lots of data around

packages/dart/sshnoports/bin/demo_socket_client.dart

@@ -0,0 +1,32 @@
+import 'dart:io';
+
+/// - simple client which talks to a demo_socket_server
+/// - sends a request for N kBytes of data to be sent to us
+/// - listens for the data and writes a message at the end
+/// saying how much it received vs expected
+void main(List<String> args) async {
+  // connect to socket on localhost, port args[0]
+  int port = int.parse(args[0]);
+  final socket = await Socket.connect('127.0.0.1', port);
+
+  // send a request for N kBytes of data to be sent to us
+  int numKbsToRequest = int.parse(args[1]);
+  socket.writeln('$numKbsToRequest');
+
+  int expected = numKbsToRequest * 1024;
+  int received = 0;
+  socket.listen(
+        (data) {
+      received += data.length;
+    },
+    onDone: () {
+      stdout.writeln('Received $received bytes ($expected expected)');
+      exit(0);
+    },
+    onError: (err) {
+      stdout.writeln('Error: $err');
+      stdout.writeln('Received $received bytes ($expected expected)');
+      exit(0);
+    },
+  );
+}

packages/dart/sshnoports/bin/demo_socket_server.dart

@@ -0,0 +1,36 @@
+import 'dart:io';
+
+/// Simple server program which binds to port args[0] and then,
+/// for each new socket connection
+/// - listens for a request to send data (see demo_socket_client.dart)
+/// - sends that much data
+/// - closes the socket
+///
+/// Sample usage:
+/// - dart demo_socket_server.dart 12345
+/// - dart demo_socket_client.dart 12345
+void main(List<String> args) async {
+
+  int port = int.parse(args[0]);
+  final server = await ServerSocket.bind(
+    InternetAddress.loopbackIPv4,
+    port,
+  );
+
+  List<int> kb = List.filled(1024, 65);
+
+  server.listen((socket) {
+    stdout.writeln('New socket connection');
+    socket.listen((bytes) async {
+      int numKbsToSend = int.parse(String.fromCharCodes(bytes));
+      stdout.writeln('Received request to send $numKbsToSend kBytes');
+      for (int i = 0; i < numKbsToSend; i++) {
+        socket.add(kb);
+      }
+      await socket.flush();
+      stdout.writeln('Wrote $numKbsToSend kBytes');
+      socket.destroy();
+      stdout.writeln('Socket closed.\n');
+    });
+  });
+}