package main
 
import (
 "fmt"
 "log"
 "net/http"
 
 "golang.org/x/net/websocket"
)
 
func Echo(ws *websocket.Conn) {
 var err error
 
 for {
 var reply string
 
 if err = websocket.Message.Receive(ws, &reply); err != nil {
 fmt.Println("Can't receive")
 break
 }
 
 fmt.Println("Received back from client: " + reply)
 
 msg := "Received: " + reply
 fmt.Println("Sending to client: " + msg)
 
 if err = websocket.Message.Send(ws, msg); err != nil {
 fmt.Println("Can't send")
 break
 }
 }
}
 
func main() {
 http.Handle("/", websocket.Handler(Echo))
 
 if err := http.ListenAndServe(":1234", nil); err != nil {
 log.Fatal("ListenAndServe:", err)
 }
}

go run test.go

var wsServer = 'ws://localhost:1234';
var websocket = new WebSocket(wsServer);
websocket.onopen = function (evt) {
 console.log("Connected to WebSocket server.");
};
 
websocket.onclose = function (evt) {
 console.log("Disconnected");
};
 
websocket.onmessage = function (evt) {
 console.log('Retrieved data from server: ' + evt.data);
};
 
websocket.onerror = function (evt, e) {
 console.log('Error occured: ' + evt.data);
};

websocket.send(2323)