fix: recover the websocket when a close goes unreported

apps/client/src/common/utils/__tests__/socket.test.ts

@@ -40,6 +40,10 @@ class MockWebSocket {
     this.onclose?.();
   }
 
+  /** Simulates a lost connection without an onclose event. */
+  closeSilently() {
+    this.readyState = MockWebSocket.CLOSED;
+  }
   open() {
     this.readyState = MockWebSocket.OPEN;
     this.onopen?.();
@@ -146,6 +150,16 @@ describe('socket connection watchdog', () => {
     expect(MockWebSocket.instances).toHaveLength(2);
   });
 
+  it('recovers when a close goes unreported', () => {
+    const socket = openConnection();
+
+    // The watchdog is the only recovery path when no close event arrives.
+    socket.closeSilently();
+
+    vi.advanceTimersByTime(watchdogInterval + socketConfig.reconnectBaseInterval * 2);
+    expect(MockWebSocket.instances).toHaveLength(2);
+  });
+
   it('ignores events from a socket which has been replaced', () => {
     const stale = openConnection();
 

apps/client/src/common/utils/socket.ts

@@ -320,13 +320,9 @@ function registerConnectionAttempt() {
  * while paused, so extended silence is evidence of a dropped connection.
  */
 function checkConnection() {
-  if (!websocket) {
-    return;
-  }
-
   const silentFor = Date.now() - lastContact;
 
-  if (websocket.readyState === WebSocket.CONNECTING) {
+  if (websocket?.readyState === WebSocket.CONNECTING) {
     // A connection attempt can otherwise hang indefinitely.
     if (silentFor > socketConfig.connectTimeout) {
       reconnectNow('WebSocket: connection attempt timed out');
@@ -334,9 +330,21 @@ function checkConnection() {
     return;
   }
 
-  if (websocket.readyState === WebSocket.OPEN && silentFor > socketConfig.silenceTimeout) {
+  if (websocket?.readyState === WebSocket.OPEN) {
+    if (silentFor > socketConfig.silenceTimeout) {
       reconnectNow('WebSocket: no data from server, reconnecting');
     }
+    return;
+  }
+
+  /**
+   * The socket is closing, closed or was never created.
+   * Closing schedules its own reconnect, this is what covers us if that did not happen,
+   * so that there is no state the client can settle in without a way out.
+   */
+  if (!reconnectTimeout) {
+    scheduleReconnect();
+  }
 }
 
 function startWatchdog() {