From 0bf62e83d226bcb9e3f4e8229094d2fcd930d202 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sat, 30 May 2026 10:01:22 -0700
Subject: [PATCH] fix: terminate websocket clients during shutdown (#3783)

---
 src/main/runtime/rpc/ws-transport.test.ts | 21 +++++++++++++++++++++
 src/main/runtime/rpc/ws-transport.ts      |  4 +++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/main/runtime/rpc/ws-transport.test.ts b/src/main/runtime/rpc/ws-transport.test.ts
index 72af8f18590..d93fe6ace10 100644
--- a/src/main/runtime/rpc/ws-transport.test.ts
+++ b/src/main/runtime/rpc/ws-transport.test.ts
@@ -316,6 +316,27 @@ describe('WebSocketTransport', () => {
     await transport.stop()
   })
 
+  it('does not wait for an unresponsive client close handshake during stop', async () => {
+    const { transport } = await createTransport()
+    await transport.start()
+    const ws = await connectWs(transport)
+    const underlying = (ws as unknown as { _socket: { pause: () => void } })._socket
+    underlying.pause()
+
+    const stopPromise = transport.stop()
+    const outcome = await Promise.race([
+      stopPromise.then(() => 'stopped' as const),
+      new Promise<'pending'>((resolve) => setTimeout(() => resolve('pending'), 100))
+    ])
+
+    if (outcome === 'pending') {
+      ws.terminate()
+      await stopPromise
+    }
+
+    expect(outcome).toBe('stopped')
+  })
+
   it('falls back to OS-assigned port when preferred port is in use', async () => {
     const { transport: first } = await createTransport()
     await first.start()
diff --git a/src/main/runtime/rpc/ws-transport.ts b/src/main/runtime/rpc/ws-transport.ts
index 07ccc095265..98166c8e988 100644
--- a/src/main/runtime/rpc/ws-transport.ts
+++ b/src/main/runtime/rpc/ws-transport.ts
@@ -251,7 +251,9 @@ export class WebSocketTransport implements RpcTransport {
 
     if (wss) {
       for (const client of wss.clients) {
-        client.close(1001, 'Server shutting down')
+        // Why: stop() is a teardown path. A half-open mobile socket may never
+        // answer a graceful close frame, which keeps httpServer.close pending.
+        client.terminate()
       }
       wss.close()
     }