From 3c6f4f492fa73a3f6d7561796bdd39e283bb80b6 Mon Sep 17 00:00:00 2001
From: Jake Bromberg <jake@funlandresearch.com>
Date: Sat, 21 Feb 2026 08:36:24 -0800
Subject: [PATCH 1/2] fix: prevent SSH timeout stacking in MirrorSQL

Each sshInstance() call added a new 5-minute timeout without clearing
the previous one, stacking dangling timeouts on rapid repeated calls.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 apps/backend/middleware/legacy/sql.mirror.ts  |  9 ++-
 .../middleware/legacy/ssh-timeout.test.ts     | 64 +++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 tests/unit/middleware/legacy/ssh-timeout.test.ts

diff --git a/apps/backend/middleware/legacy/sql.mirror.ts b/apps/backend/middleware/legacy/sql.mirror.ts
index 95c91c9..fec82c7 100644
--- a/apps/backend/middleware/legacy/sql.mirror.ts
+++ b/apps/backend/middleware/legacy/sql.mirror.ts
@@ -3,6 +3,7 @@ import { Config, NodeSSH } from 'node-ssh';
 export class MirrorSQL {
   private static _instance: MirrorSQL | null = null;
   private static _ssh: NodeSSH | null = null;
+  private static _timeoutHandle: ReturnType<typeof setTimeout> | null = null;
 
   static instance() {
     if (!this._instance) this._instance = new MirrorSQL();
@@ -24,15 +25,19 @@ export class MirrorSQL {
       await this._ssh.connect(sshConfig);
     }
 
-    setTimeout(
+    if (this._timeoutHandle) {
+      clearTimeout(this._timeoutHandle);
+    }
+    this._timeoutHandle = setTimeout(
       () => {
         if (this._ssh && this._ssh.isConnected()) {
           this._ssh.dispose();
           this._ssh = null;
         }
+        this._timeoutHandle = null;
       },
       5 * 60 * 1000
-    ); // auto-dispose after 5 minutes of inactivity
+    );
 
     return this._ssh;
   }
diff --git a/tests/unit/middleware/legacy/ssh-timeout.test.ts b/tests/unit/middleware/legacy/ssh-timeout.test.ts
new file mode 100644
index 0000000..146377a
--- /dev/null
+++ b/tests/unit/middleware/legacy/ssh-timeout.test.ts
@@ -0,0 +1,64 @@
+jest.mock('node-ssh', () => {
+  const mockSSH = {
+    isConnected: jest.fn().mockReturnValue(false),
+    connect: jest.fn().mockResolvedValue(undefined),
+    dispose: jest.fn(),
+  };
+  return { NodeSSH: jest.fn(() => mockSSH) };
+});
+
+import { MirrorSQL } from '../../../../apps/backend/middleware/legacy/sql.mirror';
+
+describe('MirrorSQL SSH timeout stacking', () => {
+  beforeEach(() => {
+    jest.useFakeTimers();
+    // Reset the singleton between tests
+    (MirrorSQL as any)._instance = null;
+    (MirrorSQL as any)._ssh = null;
+    (MirrorSQL as any)._timeoutHandle = null;
+  });
+
+  afterEach(() => {
+    jest.useRealTimers();
+  });
+
+  it('should only have one active timeout after multiple sshInstance() calls', async () => {
+    const setTimeoutSpy = jest.spyOn(global, 'setTimeout');
+    const clearTimeoutSpy = jest.spyOn(global, 'clearTimeout');
+
+    await MirrorSQL.sshInstance();
+    await MirrorSQL.sshInstance();
+    await MirrorSQL.sshInstance();
+
+    const timeoutCalls = setTimeoutSpy.mock.calls.filter(
+      ([, ms]) => ms === 5 * 60 * 1000
+    );
+
+    expect(timeoutCalls).toHaveLength(3);
+    // After 3 calls, the first 2 timeouts should have been cleared
+    expect(clearTimeoutSpy).toHaveBeenCalledTimes(2);
+
+    setTimeoutSpy.mockRestore();
+    clearTimeoutSpy.mockRestore();
+  });
+
+  it('should not dispose SSH if timeout was superseded by a newer call', async () => {
+    const { NodeSSH } = jest.requireMock('node-ssh');
+    const mockSSH = new NodeSSH();
+    mockSSH.isConnected.mockReturnValue(true);
+
+    await MirrorSQL.sshInstance();
+    // Advance partway — not enough to trigger
+    jest.advanceTimersByTime(4 * 60 * 1000);
+
+    await MirrorSQL.sshInstance();
+    // Advance past original 5 min mark — old timeout should have been cleared
+    jest.advanceTimersByTime(2 * 60 * 1000);
+
+    expect(mockSSH.dispose).not.toHaveBeenCalled();
+
+    // Advance to trigger the second (active) timeout
+    jest.advanceTimersByTime(3 * 60 * 1000);
+    expect(mockSSH.dispose).toHaveBeenCalledTimes(1);
+  });
+});

From f2de0f49b972920aa35e6d1a9fdcb993a33b6f58 Mon Sep 17 00:00:00 2001
From: Jake Bromberg <jake@funlandresearch.com>
Date: Fri, 27 Feb 2026 09:47:00 -0800
Subject: [PATCH 2/2] style: format files with Prettier

---
 tests/unit/middleware/legacy/ssh-timeout.test.ts | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tests/unit/middleware/legacy/ssh-timeout.test.ts b/tests/unit/middleware/legacy/ssh-timeout.test.ts
index 146377a..2e5fa1f 100644
--- a/tests/unit/middleware/legacy/ssh-timeout.test.ts
+++ b/tests/unit/middleware/legacy/ssh-timeout.test.ts
@@ -30,9 +30,7 @@ describe('MirrorSQL SSH timeout stacking', () => {
     await MirrorSQL.sshInstance();
     await MirrorSQL.sshInstance();
 
-    const timeoutCalls = setTimeoutSpy.mock.calls.filter(
-      ([, ms]) => ms === 5 * 60 * 1000
-    );
+    const timeoutCalls = setTimeoutSpy.mock.calls.filter(([, ms]) => ms === 5 * 60 * 1000);
 
     expect(timeoutCalls).toHaveLength(3);
     // After 3 calls, the first 2 timeouts should have been cleared