From a17ec689a36105dddf8568eac9fa605bf91492f5 Mon Sep 17 00:00:00 2001
From: lucaronin <luca.rossi.917@gmail.com>
Date: Wed, 29 Apr 2026 06:36:39 +0200
Subject: [PATCH] fix: tolerate stale vault watcher listeners

---
 src/hooks/useVaultWatcher.test.ts | 41 +++++++++++++++++++++++++++++++
 src/hooks/useVaultWatcher.ts      | 11 ++++++---
 2 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/src/hooks/useVaultWatcher.test.ts b/src/hooks/useVaultWatcher.test.ts
index d67aea68..4ffde38d 100644
--- a/src/hooks/useVaultWatcher.test.ts
+++ b/src/hooks/useVaultWatcher.test.ts
@@ -138,10 +138,51 @@ describe('useVaultWatcher', () => {
 
     unmount()
 
+    await settleWatcherSubscription()
     expect(mocks.unlisten).toHaveBeenCalledOnce()
     expect(mocks.invoke).toHaveBeenCalledWith('stop_vault_watcher')
   })
 
+  it('swallows stale native watcher unlisten failures and still stops the watcher', async () => {
+    mocks.unlisten.mockImplementationOnce(() => {
+      throw new TypeError("undefined is not an object (evaluating 'listeners[eventId].handlerId')")
+    })
+
+    const { unmount } = renderHook(() => useVaultWatcher({
+      vaultPath: '/vault',
+      onVaultChanged: vi.fn(),
+    }))
+
+    await settleWatcherSubscription()
+
+    expect(() => unmount()).not.toThrow()
+    await settleWatcherSubscription()
+    expect(mocks.unlisten).toHaveBeenCalledOnce()
+    expect(mocks.invoke).toHaveBeenCalledWith('stop_vault_watcher')
+  })
+
+  it('keeps listener replacement stable when vault paths churn', async () => {
+    mocks.unlisten.mockImplementationOnce(() => {
+      throw new TypeError("undefined is not an object (evaluating 'listeners[eventId].handlerId')")
+    })
+
+    const { rerender } = renderHook(
+      ({ vaultPath }) => useVaultWatcher({ vaultPath, onVaultChanged: vi.fn() }),
+      { initialProps: { vaultPath: '/vault-a' } },
+    )
+
+    await settleWatcherSubscription()
+
+    expect(() => rerender({ vaultPath: '/vault-b' })).not.toThrow()
+    await settleWatcherSubscription()
+
+    expect(mocks.listen).toHaveBeenCalledTimes(2)
+    expect(mocks.unlisten).toHaveBeenCalledOnce()
+    expect(mocks.invoke).toHaveBeenCalledWith('start_vault_watcher', { path: '/vault-a' })
+    expect(mocks.invoke).toHaveBeenCalledWith('start_vault_watcher', { path: '/vault-b' })
+    expect(mocks.invoke).toHaveBeenCalledWith('stop_vault_watcher')
+  })
+
   it('batches changed paths for the active vault', async () => {
     const onVaultChanged = vi.fn()
     renderHook(() => useVaultWatcher({ vaultPath: '/vault', onVaultChanged }))
diff --git a/src/hooks/useVaultWatcher.ts b/src/hooks/useVaultWatcher.ts
index 62b24916..40c8ad49 100644
--- a/src/hooks/useVaultWatcher.ts
+++ b/src/hooks/useVaultWatcher.ts
@@ -200,6 +200,12 @@ function handleWatcherEvent({
   }
 }
 
+function cleanupNativeWatcherListener(unlisten: UnlistenFn): void {
+  void Promise.resolve()
+    .then(unlisten)
+    .catch(() => {})
+}
+
 function usePendingVaultRefresh({
   vaultPathRef,
   onVaultChanged,
@@ -263,7 +269,6 @@ function useNativeVaultWatcher({
   enqueueChangedPaths: (paths: WatchPath[]) => void
   clearPendingRefresh: () => void
 }) {
-
   useEffect(() => {
     const root = normalizeWatchPath(vaultPath)
     if (!root || !isTauri()) return
@@ -275,7 +280,7 @@ function useNativeVaultWatcher({
       handleWatcherEvent({ event, root, enqueueChangedPaths })
     }).then((nextUnlisten) => {
       if (cancelled) {
-        nextUnlisten()
+        cleanupNativeWatcherListener(nextUnlisten)
       } else {
         unlisten = nextUnlisten
       }
@@ -290,7 +295,7 @@ function useNativeVaultWatcher({
     return () => {
       cancelled = true
       clearPendingRefresh()
-      unlisten?.()
+      if (unlisten) cleanupNativeWatcherListener(unlisten)
       void invoke('stop_vault_watcher').catch(() => {})
     }
   }, [vaultPath, enqueueChangedPaths, clearPendingRefresh])