From 876d729f224456d85cc696c742f280b7e277b8cd Mon Sep 17 00:00:00 2001
From: Brennan Benson <79079362+brennanb2025@users.noreply.github.com>
Date: Fri, 28 Aug 2026 17:58:03 -0700
Subject: [PATCH] fix(test): stop a leaked real timer from failing the updater
 scheduling test

The suite mixes real-timer tests with fake-timer ones against a shared
autoUpdater mock. resetUpdaterMocks() does vi.resetModules() + useRealTimers(),
neither of which cancels a real timer already armed by the module instance it
orphans. The stale instance's 1s silent-settle timer then fired inside a later
fake-timer test and re-armed a 24h automatic check against the faked clock,
producing a phantom checkForUpdates at fake offset 86400s and failing
'reschedules the next automatic check 24 hours after finding an available update'
with 'expected 1 time, got 2'.

Installing fake timers in beforeEach makes every timer this file arms
discardable: the next reset's useRealTimers() uninstalls the clock and drops
them. The assertion is unchanged.
---
 src/main/updater.startup-scheduling.test.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main/updater.startup-scheduling.test.ts b/src/main/updater.startup-scheduling.test.ts
index 06a1ea041be..a58fa0af049 100644
--- a/src/main/updater.startup-scheduling.test.ts
+++ b/src/main/updater.startup-scheduling.test.ts
@@ -27,7 +27,12 @@ vi.mock('./local-builds/local-build-feed-server', () => moduleFactories.localBui
 
 describe('updater', () => {
   beforeEach(() => {
+    // Why: resetUpdaterMocks() uninstalls fake timers, which discards every timer the previous test
+    // armed; re-faking here keeps this test's timers discardable too. On real timers a stale
+    // `vi.resetModules()`-orphaned updater instance survived to re-arm its 24h check inside a later
+    // fake-timer test, adding a phantom checkForUpdates at fake offset 24h.
     resetUpdaterMocks()
+    vi.useFakeTimers()
   })
 
   it('does not load or configure electron-updater during dev setup', async () => {