Add a Websocket example

k6/foundations/13.basic.websockets.js

@@ -0,0 +1,64 @@
+import { sleep } from 'k6';
+import { WebSocket } from 'k6/experimental/websockets';
+import { setInterval } from 'k6/experimental/timers';
+import { Counter } from "k6/metrics";
+
+let BASE_URL = __ENV.BASE_URL || 'http://localhost:3333';
+
+BASE_URL = BASE_URL.replace("https://", "wss://");
+BASE_URL = BASE_URL.replace("http://", "ws://");
+
+export const options = {
+ scenarios: {
+ receiver: {
+ exec: "receiver",
+ executor: "ramping-vus",
+ executor: 'shared-iterations',
+ iterations: 1,
+ maxDuration: '1m',
+ },
+ sender: {
+ exec: "sender",
+ executor: 'shared-iterations',
+ iterations: 20,
+ vus: 10,
+
+ // delay the start to get the receiver ready
+ startTime: '2s',
+ },
+
+ }
+};
+
+// send two WS messages
+export function sender() {
+ const ws = new WebSocket(`${BASE_URL}/ws`);
+ ws.addEventListener('open', () => {
+ ws.send(JSON.stringify({ user: `VU ${__VU}`, msg: "order_pizza" }));
+ sleep(0.2);
+ ws.send(JSON.stringify({ user: `VU ${__VU}`, msg: "pizza_status?" }));
+ sleep(0.1);
+ ws.close();
+ });
+}
+
+export function receiver () {
+
+ // Close the WS connection to end the iteration once the number of expected messages is received.
+
+ // Be aware that a local counter (`messageCounter`) is valid here because only one `receiver` iteration runs.
+ let messageCounter = 0;
+ const totalExpectedMessages = 20*2; // 20 iterations * 2 messages per iteration
+
+ const ws = new WebSocket(`${BASE_URL}/ws`);
+ ws.addEventListener('open', () => {
+ ws.addEventListener('message', (e) => {
+ const msg = JSON.parse(e.data);
+ console.log(`VU ${__VU} received: ${msg.user} msg: ${msg.msg}`);
+ messageCounter++;
+ if (messageCounter === totalExpectedMessages) {
+ ws.close();
+ }
+ });
+ });
+}