var rocketChatSocket = new WebSocket("ws://localhost:3000/websocket");
var connectRequest = {
    "msg": "connect",
    "version": "1",
    "support": ["1", "pre2", "pre1"]
 }
 rocketChatSocket.send(JSON.stringify(connectRequest));
var loginRequest = {
    "msg": "method",
    "method": "login",
    "id": "42",
    "params": [
        { "user" : "chuyenbka@gmail.com", "password" : "123456" }
      ]
}

rocketChatSocket.send(JSON.stringify(loginRequest));