Watch party refresh: Chat/Queue/Room tabs, host transport, gentle sync, heartbeat and latency-aware reconnect, in-place section updates

server/party.test.js

@@ -187,3 +187,18 @@ describe('watch party seat rules', () => {
     host.send({ type: 'end' }); await host.closed;
   });
 });
+
+test('heartbeat replies only to the sender with the server clock', async () => {
+  const h = client({ role: 'host', pid: 'heartbeat-host', name: 'Host' });
+  const hello = await h.next('hello');
+  const g = client({ role: 'guest', pid: 'heartbeat-guest', code: hello.code, name: 'Guest' });
+  await g.next('hello');
+  const before = Date.now();
+  g.send({ type: 'ping', echo: 12345 });
+  const pong = await g.next('pong');
+  expect(pong.echo).toBe(12345);
+  expect(pong.now).toBeGreaterThanOrEqual(before);
+  expect(pong.now).toBeLessThanOrEqual(Date.now());
+  await expect(h.next('pong', 50)).rejects.toThrow('timeout pong');
+  g.ws.close(); h.send({ type: 'end' }); await h.closed;
+});