From 060a5311efbde2ffa6cac5e3eb5817a4fd1c38d2 Mon Sep 17 00:00:00 2001
From: Isaac Sanchez-Hawkins <266845420+isanchez404@users.noreply.github.com>
Date: Tue, 12 May 2026 04:01:31 -0400
Subject: [PATCH] fix(terminal): remove upgrade listener on shutdown (#1233)

Co-authored-by: Isaac Sanchez <isanchez-hawkins@arize.com>
---
 packages/web/server/lib/terminal/runtime.js   |  8 +++-
 .../web/server/lib/terminal/runtime.test.js   | 44 +++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 packages/web/server/lib/terminal/runtime.test.js

diff --git a/packages/web/server/lib/terminal/runtime.js b/packages/web/server/lib/terminal/runtime.js
index 90eada79..2d0ac299 100644
--- a/packages/web/server/lib/terminal/runtime.js
+++ b/packages/web/server/lib/terminal/runtime.js
@@ -385,7 +385,7 @@ export function createTerminalRuntime({
     });
   });
 
-  server.on('upgrade', (req, socket, head) => {
+  const upgradeHandler = (req, socket, head) => {
     const pathname = parseRequestPathname(req.url);
     if (pathname !== TERMINAL_INPUT_WS_PATH) {
       return;
@@ -422,7 +422,9 @@ export function createTerminalRuntime({
     };
 
     void handleUpgrade();
-  });
+  };
+
+  server.on('upgrade', upgradeHandler);
 
   const wireTerminalSession = (sessionId, session) => {
     session.ptyProcess.onData((data) => {
@@ -791,6 +793,8 @@ export function createTerminalRuntime({
   });
 
   const shutdown = async () => {
+    server.off('upgrade', upgradeHandler);
+
     if (idleSweepInterval) {
       clearInterval(idleSweepInterval);
     }
diff --git a/packages/web/server/lib/terminal/runtime.test.js b/packages/web/server/lib/terminal/runtime.test.js
new file mode 100644
index 00000000..326e1b4b
--- /dev/null
+++ b/packages/web/server/lib/terminal/runtime.test.js
@@ -0,0 +1,44 @@
+import { EventEmitter } from 'node:events';
+import fs from 'node:fs';
+import path from 'node:path';
+import { describe, expect, it } from 'vitest';
+
+import { createTerminalRuntime } from './runtime.js';
+
+function createRuntime(server) {
+  const app = {
+    post() {},
+    get() {},
+    delete() {},
+  };
+
+  return createTerminalRuntime({
+    app,
+    server,
+    express: { text: () => (_req, _res, next) => next?.() },
+    fs,
+    path,
+    uiAuthController: null,
+    buildAugmentedPath: () => process.env.PATH || '',
+    searchPathFor: () => null,
+    isExecutable: () => false,
+    isRequestOriginAllowed: async () => true,
+    rejectWebSocketUpgrade() {},
+    TERMINAL_INPUT_WS_HEARTBEAT_INTERVAL_MS: 30_000,
+    TERMINAL_INPUT_WS_REBIND_WINDOW_MS: 1_000,
+    TERMINAL_INPUT_WS_MAX_REBINDS_PER_WINDOW: 3,
+  });
+}
+
+describe('terminal runtime', () => {
+  it('removes its websocket upgrade listener on shutdown', async () => {
+    const server = new EventEmitter();
+    const runtime = createRuntime(server);
+
+    expect(server.listenerCount('upgrade')).toBe(1);
+
+    await runtime.shutdown();
+
+    expect(server.listenerCount('upgrade')).toBe(0);
+  });
+});