1 files changed, 49 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/third_party/websockets/example/quickstart/counter.py b/testing/web-platform/tests/tools/third_party/websockets/example/quickstart/counter.py
new file mode 100644
index 0000000000..566e12965e
--- /dev/null
+++ b/testing/web-platform/tests/tools/third_party/websockets/example/quickstart/counter.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+import asyncio
+import json
+import logging
+import websockets
+
+logging.basicConfig()
+
+USERS = set()
+
+VALUE = 0
+
+def users_event():
+    return json.dumps({"type": "users", "count": len(USERS)})
+
+def value_event():
+    return json.dumps({"type": "value", "value": VALUE})
+
+async def counter(websocket):
+    global USERS, VALUE
+    try:
+        # Register user
+        USERS.add(websocket)
+        websockets.broadcast(USERS, users_event())
+        # Send current state to user
+        await websocket.send(value_event())
+        # Manage state changes
+        async for message in websocket:
+            event = json.loads(message)
+            if event["action"] == "minus":
+                VALUE -= 1
+                websockets.broadcast(USERS, value_event())
+            elif event["action"] == "plus":
+                VALUE += 1
+                websockets.broadcast(USERS, value_event())
+            else:
+                logging.error("unsupported event: %s", event)
+    finally:
+        # Unregister user
+        USERS.remove(websocket)
+        websockets.broadcast(USERS, users_event())
+
+async def main():
+    async with websockets.serve(counter, "localhost", 6789):
+        await asyncio.Future()  # run forever
+
+if __name__ == "__main__":
+    asyncio.run(main())