From 8a0aaf9966f72fc45eedd17987ab7fbecf4f2d4a Mon Sep 17 00:00:00 2001
From: Austin Pickett <pickett.austin@gmail.com>
Date: Thu, 1 Oct 2026 09:50:47 -0400
Subject: [PATCH] fix(desktop): keep a failed watch snapshot distinct from an
 empty directory

The storm-breaker poll mapped a throwing snapshot to '', which is also the
valid readdir snapshot of an empty directory, so an empty watched directory
vanishing after a trip was never reported. Failures are now null.
---
 .../electron/watch-storm-breaker.test.ts      | 20 +++++++++++++++++++
 apps/desktop/electron/watch-storm-breaker.ts  |  9 +++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/apps/desktop/electron/watch-storm-breaker.test.ts b/apps/desktop/electron/watch-storm-breaker.test.ts
index 6bbd1b4d0c..374abcb3d3 100644
--- a/apps/desktop/electron/watch-storm-breaker.test.ts
+++ b/apps/desktop/electron/watch-storm-breaker.test.ts
@@ -179,4 +179,24 @@ describe('guardedWatch', () => {
 
     expect(onPollChange).toHaveBeenCalledTimes(1)
   })
+
+  test('an empty directory vanishing is still a change (error is not the empty snapshot)', () => {
+    let gone = false
+
+    const { fw, onPollChange } = setup('win32', {
+      snapshot: () => {
+        if (gone) {
+          throw new Error('ENOENT')
+        }
+
+        return ''
+      }
+    })
+
+    fw.emit(WATCH_STORM_MAX_EVENTS + 1)
+    gone = true
+    vi.advanceTimersByTime(WATCH_STORM_POLL_MS)
+
+    expect(onPollChange).toHaveBeenCalledTimes(1)
+  })
 })
diff --git a/apps/desktop/electron/watch-storm-breaker.ts b/apps/desktop/electron/watch-storm-breaker.ts
index 77b5d01eb9..fed18ee089 100644
--- a/apps/desktop/electron/watch-storm-breaker.ts
+++ b/apps/desktop/electron/watch-storm-breaker.ts
@@ -55,11 +55,16 @@ export function stormBreakerArmed(platform: string): boolean {
   return platform === 'win32'
 }
 
-function safeSnapshot(snapshot: () => string): string {
+/**
+ * `null` = the snapshot failed (target removed or unreadable). Kept distinct
+ * from the empty string, which is the valid snapshot of an empty directory, so
+ * an empty directory vanishing still compares as a change.
+ */
+function safeSnapshot(snapshot: () => string): string | null {
   try {
     return snapshot()
   } catch {
-    return ''
+    return null
   }
 }