Add ability to send application data with WebSocket ping frames

examples/websocket.js

@@ -10,6 +10,14 @@ export default function () {
             console.log('connected');
             socket.send(Date.now());
 
+            // Send a regular ping
+            socket.ping();
+            console.log("Sent a ping without application data");
+
+            // Send a ping with application data
+            socket.ping("application-data");
+            console.log("Sent a ping with application data");
+
             socket.setInterval(function timeout() {
                 socket.ping();
                 console.log("Pinging every 1sec (setInterval test)");

internal/js/modules/k6/experimental/websockets/websockets.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"net/url"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -678,24 +679,58 @@ func isArrayBufferView(rt *sobek.Runtime, v sobek.Value) (bool, error) {
 }
 
 // Ping sends a ping message over the websocket.
-func (w *webSocket) ping() {
+// It can optionally include application data as per RFC 6455 section 5.5.2.
+func (w *webSocket) ping(args ...sobek.Value) {
 	w.assertStateOpen()
 
 	pingID := strconv.Itoa(w.sendPings.counter)
 
+	var data []byte
+	if len(args) > 0 && !sobek.IsUndefined(args[0]) && !sobek.IsNull(args[0]) {
+		if args[0].String() != "" {
+			// Use a special delimiter "|" to separate ping ID from application data
+			data = []byte(pingID + "|" + args[0].String())
+		} else {
+			data = []byte(pingID)
+		}
+	} else {
+		data = []byte(pingID)
+	}
+
 	w.writeQueueCh <- message{
 		mtype: websocket.PingMessage,
-		data:  []byte(pingID),
+		data:  data,
 		t:     time.Now(),
 	}
 
 	w.sendPings.timestamps[pingID] = time.Now()
 	w.sendPings.counter++
 }
 
-func (w *webSocket) trackPong(pingID string) {
+func (w *webSocket) trackPong(pongData string) {
 	pongTimestamp := time.Now()
 
+	var pingID string
+	if parts := strings.SplitN(pongData, "|", 2); len(parts) > 0 {
+		pingID = parts[0]
+	} else {
+		for i, c := range pongData {
+			if c < '0' || c > '9' {
+				// Found non-numeric character, extract the ID
+				pingID = pongData[:i]
+				break
+			}
+			if i == len(pongData)-1 {
+				pingID = pongData
+			}
+		}
+	}
+
+	if pingID == "" {
+		w.vu.State().Logger.Warnf("received pong with invalid ping ID format")
+		return
+	}
+
 	pingTimestamp, ok := w.sendPings.timestamps[pingID]
 	if !ok {
 		// We received a pong for a ping we didn't send; ignore

internal/js/modules/k6/experimental/websockets/websockets_test.go

@@ -1546,3 +1546,59 @@ func TestReadyStateSwitch(t *testing.T) {
 	logs := hook.Drain()
 	require.Len(t, logs, 0)
 }
+
+func TestSessionPingWithApplicationData(t *testing.T) {
+	t.Parallel()
+	tb := httpmultibin.NewHTTPMultiBin(t)
+	sr := tb.Replacer.Replace
+
+	ts := newTestState(t)
+
+	_, err := ts.runtime.RunOnEventLoop(sr(`
+			var ws = new WebSocket("WSBIN_URL/ws-echo")
+			var applicationData = "hello-ping-data";
+			ws.onopen = () => {
+				ws.ping(applicationData)
+			}
+
+			ws.onpong = () => {
+				call("from onpong")
+				ws.close()
+			}
+			ws.onerror = (e) => { throw JSON.stringify(e) }
+		`))
+
+	require.NoError(t, err)
+
+	samplesBuf := metrics.GetBufferedSamples(ts.samples)
+	assertSessionMetricsEmitted(t, samplesBuf, "", sr("WSBIN_URL/ws-echo"), http.StatusSwitchingProtocols, "")
+	assert.Equal(t, []string{"from onpong"}, ts.callRecorder.Recorded())
+}
+
+func TestSessionPingWithNumericApplicationData(t *testing.T) {
+	t.Parallel()
+	tb := httpmultibin.NewHTTPMultiBin(t)
+	sr := tb.Replacer.Replace
+
+	ts := newTestState(t)
+
+	_, err := ts.runtime.RunOnEventLoop(sr(`
+			var ws = new WebSocket("WSBIN_URL/ws-echo")
+			var applicationData = "123456-numeric-ping-data";
+			ws.onopen = () => {
+				ws.ping(applicationData)
+			}
+
+			ws.onpong = () => {
+				call("from onpong")
+				ws.close()
+			}
+			ws.onerror = (e) => { throw JSON.stringify(e) }
+		`))
+
+	require.NoError(t, err)
+
+	samplesBuf := metrics.GetBufferedSamples(ts.samples)
+	assertSessionMetricsEmitted(t, samplesBuf, "", sr("WSBIN_URL/ws-echo"), http.StatusSwitchingProtocols, "")
+	assert.Equal(t, []string{"from onpong"}, ts.callRecorder.Recorded())
+}

internal/js/modules/k6/ws/ws.go

@@ -376,10 +376,22 @@ func (s *Socket) SendBinary(message sobek.Value) {
 }
 
 // Ping sends a ping message over the websocket.
-func (s *Socket) Ping() {
+// It can optionally include application data as per RFC 6455 section 5.5.2.
+func (s *Socket) Ping(args ...sobek.Value) {
 	deadline := time.Now().Add(writeWait)
 	pingID := strconv.Itoa(s.pingSendCounter)
-	data := []byte(pingID)
+
+	var data []byte
+	if len(args) > 0 && !sobek.IsUndefined(args[0]) && !sobek.IsNull(args[0]) {
+		if args[0].String() != "" {
+			// Add the pingID with a delimiter before the application data
+			data = []byte(pingID + "|" + args[0].String())
+		} else {
+			data = []byte(pingID)
+		}
+	} else {
+		data = []byte(pingID)
+	}
 
 	err := s.conn.WriteControl(websocket.PingMessage, data, deadline)
 	if err != nil {
@@ -391,9 +403,28 @@ func (s *Socket) Ping() {
 	s.pingSendCounter++
 }
 
-func (s *Socket) trackPong(pingID string) {
+func (s *Socket) trackPong(pongData string) {
 	pongTimestamp := time.Now()
 
+	var pingID string
+	if parts := strings.SplitN(pongData, "|", 2); len(parts) > 0 {
+		pingID = parts[0]
+	} else {
+		for i, c := range pongData {
+			if c < '0' || c > '9' {
+				pingID = pongData[:i]
+				break
+			}
+			if i == len(pongData)-1 {
+				pingID = pongData
+			}
+		}
+	}
+
+	if pingID == "" {
+		return
+	}
+
 	if _, ok := s.pingSendTimestamps[pingID]; !ok {
 		// We received a pong for a ping we didn't send; ignore
 		// (this shouldn't happen with a compliant server)

internal/js/modules/k6/ws/ws_test.go

@@ -1226,3 +1226,63 @@ func TestWSConnectDisableThrowErrorOption(t *testing.T) {
 	entries := logHook.Drain()
 	assert.Empty(t, entries)
 }
+
+func TestSessionPingWithApplicationData(t *testing.T) {
+	t.Parallel()
+	tb := httpmultibin.NewHTTPMultiBin(t)
+	sr := tb.Replacer.Replace
+
+	test := newTestState(t)
+	_, err := test.VU.Runtime().RunString(sr(`
+		var pongReceived = false;
+		var applicationData = "hello-ping-data";
+		var res = ws.connect("WSBIN_URL/ws-echo", function(socket){
+			socket.on("open", function(data) {
+				// Send ping with application data
+				socket.ping(applicationData);
+			});
+			socket.on("pong", function() {
+				pongReceived = true;
+				socket.close();
+			});
+			socket.setTimeout(function (){socket.close();}, 3000);
+		});
+		if (!pongReceived) {
+			throw new Error ("sent ping with application data but didn't get pong back");
+		}
+		`))
+	require.NoError(t, err)
+	samplesBuf := metrics.GetBufferedSamples(test.samples)
+	assertSessionMetricsEmitted(t, samplesBuf, "", sr("WSBIN_URL/ws-echo"), statusProtocolSwitch, "")
+	assertMetricEmittedCount(t, metrics.WSPingName, samplesBuf, sr("WSBIN_URL/ws-echo"), 1)
+}
+
+func TestSessionPingWithNumericApplicationData(t *testing.T) {
+	t.Parallel()
+	tb := httpmultibin.NewHTTPMultiBin(t)
+	sr := tb.Replacer.Replace
+
+	test := newTestState(t)
+	_, err := test.VU.Runtime().RunString(sr(`
+		var pongReceived = false;
+		var applicationData = "123456-numeric-ping-data";
+		var res = ws.connect("WSBIN_URL/ws-echo", function(socket){
+			socket.on("open", function(data) {
+				// Send ping with application data that starts with numbers
+				socket.ping(applicationData);
+			});
+			socket.on("pong", function() {
+				pongReceived = true;
+				socket.close();
+			});
+			socket.setTimeout(function (){socket.close();}, 3000);
+		});
+		if (!pongReceived) {
+			throw new Error ("sent ping with numeric application data but didn't get pong back");
+		}
+		`))
+	require.NoError(t, err)
+	samplesBuf := metrics.GetBufferedSamples(test.samples)
+	assertSessionMetricsEmitted(t, samplesBuf, "", sr("WSBIN_URL/ws-echo"), statusProtocolSwitch, "")
+	assertMetricEmittedCount(t, metrics.WSPingName, samplesBuf, sr("WSBIN_URL/ws-echo"), 1)
+}