fix(realtime): isolate notification failures

src/server/realtime/sessionEventHub.test.ts

@@ -54,6 +54,28 @@ describe("SessionEventHub", () => {
     expect(removed.send).not.toHaveBeenCalled();
   });
 
+  it("continues publishing session events when one socket send fails", () => {
+    const hub = new SessionEventHub();
+    const failed = new FakeSocket();
+    const healthy = new FakeSocket();
+    failed.send.mockImplementation(() => { throw new Error("socket closed"); });
+    hub.add("s1", failed);
+    hub.add("s1", healthy);
+
+    hub.publish("s1", { type: "assistant.delta", text: "hello" });
+
+    expect(failed.send).toHaveBeenCalledOnce();
+    expect(healthy.send).toHaveBeenCalledWith(JSON.stringify({ type: "assistant.delta", text: "hello", seq: 1 }));
+    expect(hub.currentSeq("s1")).toBe(1);
+
+    failed.send.mockClear();
+    hub.publish("s1", { type: "assistant.delta", text: "again" });
+
+    expect(failed.send).not.toHaveBeenCalled();
+    expect(healthy.send).toHaveBeenLastCalledWith(JSON.stringify({ type: "assistant.delta", text: "again", seq: 2 }));
+    expect(hub.currentSeq("s1")).toBe(2);
+  });
+
   it("publishes global events only to global sockets", () => {
     const hub = new SessionEventHub();
     const globalSocket = new FakeSocket();
@@ -78,6 +100,26 @@ describe("SessionEventHub", () => {
     expect(sessionSocket.send).not.toHaveBeenCalled();
   });
 
+  it("continues publishing unstamped global events when one socket send fails", () => {
+    const hub = new SessionEventHub();
+    const failed = new FakeSocket();
+    const healthy = new FakeSocket();
+    failed.send.mockImplementation(() => { throw new Error("socket closed"); });
+    hub.addGlobal(failed);
+    hub.addGlobal(healthy);
+
+    hub.publishGlobal({ type: "session.name", sessionId: "s1", name: "Renamed" });
+
+    expect(failed.send).toHaveBeenCalledOnce();
+    expect(healthy.send).toHaveBeenCalledWith(JSON.stringify({ type: "session.name", sessionId: "s1", name: "Renamed" }));
+
+    failed.send.mockClear();
+    hub.publishGlobal({ type: "session.name", sessionId: "s1", name: "Renamed again" });
+
+    expect(failed.send).not.toHaveBeenCalled();
+    expect(healthy.send).toHaveBeenLastCalledWith(JSON.stringify({ type: "session.name", sessionId: "s1", name: "Renamed again" }));
+  });
+
   it("stamps a monotonically increasing per-session seq on published events", () => {
     const hub = new SessionEventHub();
     const socket = new FakeSocket();

src/server/realtime/sessionEventHub.ts

@@ -34,9 +34,7 @@ export class SessionEventHub {
     const seq = (this.seqBySession.get(sessionId) ?? 0) + 1;
     this.seqBySession.set(sessionId, seq);
     const payload = JSON.stringify({ ...projectBrowserSessionEvent(event), seq });
-    for (const socket of this.socketsBySession.get(sessionId) ?? []) {
-      if (socket.readyState === socket.OPEN) socket.send(payload);
-    }
+    this.sendToSockets(this.socketsBySession.get(sessionId), payload);
   }
 
   /**
@@ -55,8 +53,18 @@ export class SessionEventHub {
 
   publishRealtime(event: RealtimeEvent): void {
     const payload = JSON.stringify(event);
-    for (const socket of this.globalSockets) {
-      if (socket.readyState === socket.OPEN) socket.send(payload);
+    this.sendToSockets(this.globalSockets, payload);
+  }
+
+  private sendToSockets(sockets: Set<RealtimeSocket> | undefined, payload: string): void {
+    if (sockets === undefined) return;
+    for (const socket of sockets) {
+      if (socket.readyState !== socket.OPEN) continue;
+      try {
+        socket.send(payload);
+      } catch {
+        sockets.delete(socket);
+      }
     }
   }
 }