From b356d59fd9775b4a39f5b83b389c772b3713d6aa Mon Sep 17 00:00:00 2001
From: lawrencecchen <54008264+lawrencecchen@users.noreply.github.com>
Date: Tue, 3 Nov 2026 03:43:14 +0000
Subject: [PATCH] test(updater): UpdateInstallCheckTests fakes the frontmost
 app, as its sibling suites do

theRelaunchRecordsTheInstallAndTheNextLaunchJudgesIt and
anInstallThatEndsWithTheAppRunningLeavesNoRecord call
updaterWillRelaunchApplication(), which reads UpdaterService.frontmost.
Its default is AppKit's answer (UpdateFrontmostApp.current()), which reads
NSApp.isActive. The package-test lane runs each suite in its own process,
and this suite makes no NSApplication, so NSApp is nil and the read traps
(UpdateRelaunchFocus.swift:99, 'Unexpectedly found nil'): the whole suite
crashes. It passed only when an earlier suite in the same process had made
NSApplication.shared.

The seam is there for tests ('AppKit in the app, a fake in tests');
UpdateRelaunchFocusTests and UpdateRelaunchHandoffTests set it. The helper
now sets it too. No product change: the app always has NSApp.

Culprit: 622900473e8 (#31178) added the suite without the fake.
Red: fleet job 2bf90b6c18ca136f3fb6c15d at feat 11dfe910c93.
---
 .../Tests/CmuxNextAppTests/UpdateInstallCheckTests.swift | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Packages/macOS/CmuxNext/Tests/CmuxNextAppTests/UpdateInstallCheckTests.swift b/Packages/macOS/CmuxNext/Tests/CmuxNextAppTests/UpdateInstallCheckTests.swift
index 30b3b4c39039..1695ae9b6503 100644
--- a/Packages/macOS/CmuxNext/Tests/CmuxNextAppTests/UpdateInstallCheckTests.swift
+++ b/Packages/macOS/CmuxNext/Tests/CmuxNextAppTests/UpdateInstallCheckTests.swift
@@ -17,8 +17,13 @@ import Testing
         let identity = UpdateBuildIdentity(bundleIdentifier: "com.cmuxterm.app.debug.install-check", shortVersion: "1.0.0",
                                            build: build, minimumSystemVersion: nil,
                                            infoFeedURL: "https://files-next.cmux.com/nightly-next/appcast-arm64.xml", hasPublicKey: false)
-        return UpdaterService(identity: identity, policy: ManagedUpdatePolicy { false }, defaults: defaults,
-                              enableSparkle: false, recordsUpdates: false, now: { time })
+        let updater = UpdaterService(identity: identity, policy: ManagedUpdatePolicy { false }, defaults: defaults,
+                                     enableSparkle: false, recordsUpdates: false, now: { time })
+        // The relaunch reads the frontmost app (``UpdaterService/frontmost``); AppKit's answer needs
+        // an NSApplication, which a test process that made none lacks (`NSApp` is nil and the read
+        // traps). This app is frontmost, as when a person clicks Restart to Update.
+        updater.frontmost = { UpdateFrontmostApp(isThisApp: true, pid: 1, bundleID: "com.cmuxterm.app.debug.install-check") }
+        return updater
     }
 
     @Test func aLaunchOnTheOldBuildIsAFailedInstall() {