Convert TCP client from c# to nodejs

Question

We are converting our TCP client written in c# code to nodejs.

The TCP client in c# is written as:

    using (TcpClient tcpClient = new TcpClient())
    {
       tcpClient.Connect(HOST, port);
       NetworkStream stream = tcpClient.GetStream();
       StreamWriter streamWriter = new StreamWriter((Stream)stream);
       string str = "{ \"message\" : \"" + message + "\" }";
       streamWriter.Write(str);
       streamWriter.Flush();
       int num = 0;
       stream.WriteByte((byte)num);
       tcpClient.Close();
    }

---

The nodejs converted code is

     var client = new net.Socket();
     client.connect(PORT, HOST, function () {
        var command = { "message" : "message" };
        var message = JSON.stringify(command);
        client.write(message, function () {
           client.write('successfully sent the message');
           client.destroy();
        });
     });

This talk to a third party server. We are getting a correct response back from the server when using the c# while no response from nodejs

Not sure what I am missing. Please help

UPDATE:

I finally figured it out, after using WireShark to inspect the packets. The C# code was appending a NULL (ascii: 00) to the message while the nodejs code wasn't after appending a NULL value, the third party server started responding to the request

Answer 1

Try something like this, (I'm including a Node.js test server):

var net = require('net');

var server = net.createServer(function(socket) {    
    socket.write('Hello from server!');

    socket.on('data', function(data) {
        console.log('Server: Received: ' + data);
    });
});

server.listen(PORT);

var client = new net.Socket();
client.connect(PORT, HOST, () => {
    console.log('Client: Connected to server.');
    var message = JSON.stringify({ "message" : "message" }) + '\r\n';
    client.write(message, () => {
       client.write('successfully sent the message\r\n' , () => {
           console.log("We're done with the client, closing..");
           client.end();
       });
    });
});

client.on('data', function(data) {
    console.log('Client: Received data: ' + data);
});

client.on('close', function() {
    console.log('Client: Connection closed');
});

You can test this out by running on the same machine and using the same PORT. Then you can try using another address ( and port). I think the issue with the previous code is that you were calling client.destroy straight after client.write. This causes an error.