node.js TCP client/server example

tcp_client.js

const { Socket } = require("net");

const tcpClient = (address, port, data) =>
  new Promise((resolve, reject) => {
    const client = new Socket();

    client.connect({ port, address });

    client.on("connect", () => {
      client.write(Buffer.from(
        typeof data === "string"
          ? data
          : JSON.stringify(data)
      ));
      client.end();
    });

    client.on("error", reject);
    client.on("data", resolve);
  })

tcp_server.js

const { createServer } = require("net");

const tcpServer = createServer(socket => {
  socket.on("data", data => console.log(
    `[>] server: ${data.toString()}`
  ));
  socket.write("Pong!");
  socket.pipe(socket);
});

tcpServer.listen(1339, "127.0.0.1", async () => {
  const response = await tcpClient("127.0.0.1", 1339, "Ping");
  console.log(`[<] client: ${response.toString()}`);
});