fix: show Finder actions on external drives

Config/products/macpacker.json

@@ -38,6 +38,30 @@
       {
         "version": "1.0.1",
         "items": [
+          {
+            "type": "fix",
+            "title": {
+              "en": "Finder actions on external drives",
+              "zh-Hans": "外置驱动器上的 Finder 操作",
+              "fr": "Actions Finder sur les disques externes",
+              "de": "Finder-Aktionen auf externen Laufwerken",
+              "it": "Azioni Finder sui dischi esterni",
+              "ja": "外付けドライブでの Finder アクション",
+              "fa": "عملیات Finder در درایوهای خارجی",
+              "pl": "Akcje Finder na dyskach zewnętrznych",
+              "pt-BR": "Ações do Finder em unidades externas",
+              "ru": "Действия Finder на внешних дисках",
+              "uk": "Дії Finder на зовнішніх дисках",
+              "es-MX": "Acciones de Finder en discos externos",
+              "ko": "외장 드라이브의 Finder 동작",
+              "nl": "Finder-acties op externe schijven",
+              "vi": "Thao tác Finder trên ổ đĩa ngoài",
+              "tr": "Harici sürücülerde Finder işlemleri"
+            },
+            "issues": [
+              "275"
+            ]
+          },
           {
             "type": "fix",
             "highlight": true,

FinderExtension/FinderSync.swift

@@ -53,18 +53,36 @@ class FinderSync: FIFinderSync {
         tb.start()
         log.debug("FinderSync() launched from \(Bundle.main.bundlePath as NSString)")
 
-        // Set up the directory we are syncing.
-        let syncUrls: Set<URL> = [
-            self.baseFolderUrl,
-            URL(fileURLWithPath: "/Users/\(ProcessInfo.processInfo.userName)")
-        ]
-        FIFinderSyncController.default().directoryURLs = syncUrls
-        log.debug("Initializing on...")
-        for syncUrl in syncUrls {
-            log.debug("\t\(syncUrl.path)")
+        let notifications = NSWorkspace.shared.notificationCenter
+        for name in [NSWorkspace.didMountNotification, NSWorkspace.didUnmountNotification,
+                     NSWorkspace.didRenameVolumeNotification] {
+            notifications.addObserver(self, selector: #selector(volumesDidChange(_:)), name: name, object: nil)
         }
+        refreshObservedDirectories()
     }
-
+
+    deinit {
+        NSWorkspace.shared.notificationCenter.removeObserver(self)
+    }
+
+    @objc private func volumesDidChange(_ notification: Notification) {
+        refreshObservedDirectories()
+    }
+
+    private func refreshObservedDirectories() {
+        // Finder needs each mounted volume's root, not just its /Volumes parent.
+        // This only controls menu availability; file access still goes through
+        // the main app's existing folder permission flow.
+        let volumes = FileManager.default.mountedVolumeURLs(
+            includingResourceValuesForKeys: nil, options: [.skipHiddenVolumes]) ?? []
+        let roots = FinderObservedDirectories.urls(
+            homeDirectory: baseFolderUrl,
+            userName: ProcessInfo.processInfo.userName,
+            mountedVolumes: volumes)
+        FIFinderSyncController.default().directoryURLs = roots
+        log.debug("Observing Finder directories: \(roots.map(\.path).sorted())")
+    }
+
     // MARK: - Primary Finder Sync protocol methods
 
     override func beginObservingDirectory(at url: URL) {

Modules/Sources/FinderMenu/FinderObservedDirectories.swift

@@ -0,0 +1,19 @@
+import Foundation
+
+/// Finder asks for context menus only underneath these roots. Watching a root
+/// does not grant the app permission to read or write its files.
+public enum FinderObservedDirectories {
+    public static func urls(homeDirectory: URL, userName: String, mountedVolumes: [URL]) -> Set<URL> {
+        var roots: Set<URL> = [
+            URL(fileURLWithPath: homeDirectory.path, isDirectory: true),
+            URL(fileURLWithPath: "/Users/\(userName)", isDirectory: true)
+        ]
+        for volume in mountedVolumes where volume.isFileURL {
+            let root = URL(fileURLWithPath: volume.standardizedFileURL.path, isDirectory: true)
+            // Registering / would include system directories and every user's
+            // home. Retain the existing home scope on the startup volume.
+            if root.path != "/" { roots.insert(root) }
+        }
+        return roots
+    }
+}

Modules/Tests/CoreTests/FinderObservedDirectoriesTests.swift

@@ -0,0 +1,52 @@
+import Foundation
+import Testing
+import FinderMenu
+
+extension AllCoreTests {
+    struct FinderObservedDirectoriesTests {
+        private let home = URL(fileURLWithPath: "/Users/tester", isDirectory: true)
+
+        @Test("Finder watches mounted volumes as well as the home folder")
+        func externalVolumes() {
+            let external = URL(fileURLWithPath: "/Volumes/External Drive", isDirectory: true)
+            let roots = FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: [external])
+            #expect(roots.contains(external))
+            #expect(roots.contains(home))
+        }
+
+        @Test("Sandbox home keeps the real home fallback")
+        func sandboxHome() {
+            let sandbox = URL(fileURLWithPath: "/Users/tester/Library/Containers/app/Data", isDirectory: true)
+            let roots = FinderObservedDirectories.urls(homeDirectory: sandbox, userName: "tester", mountedVolumes: [])
+            #expect(roots == [sandbox, home])
+        }
+
+        @Test("Mounted roots are normalized and non-file URLs are ignored")
+        func normalizedRoots() {
+            let volume = URL(fileURLWithPath: "/Volumes/External Drive", isDirectory: true)
+            let roots = FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: [
+                URL(fileURLWithPath: "/Volumes/External Drive/./"), volume,
+                URL(string: "https://example.com/volume")!
+            ])
+            #expect(roots == [home, volume])
+        }
+
+        @Test("Finder does not watch the entire startup volume")
+        func excludesStartupRoot() {
+            let roots = FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: [URL(fileURLWithPath: "/")])
+            #expect(!roots.contains(URL(fileURLWithPath: "/")))
+        }
+
+        @Test("Volume refresh removes stale roots after unmount or rename")
+        func refresh() {
+            let old = URL(fileURLWithPath: "/Volumes/Old", isDirectory: true)
+            let new = URL(fileURLWithPath: "/Volumes/New", isDirectory: true)
+            let before = FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: [old])
+            let after = FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: [new])
+            #expect(before.contains(old))
+            #expect(after.contains(new))
+            #expect(!after.contains(old))
+            #expect(FinderObservedDirectories.urls(homeDirectory: home, userName: "tester", mountedVolumes: []).contains(home))
+        }
+    }
+}

docs/verification/issue-275/README.md

@@ -0,0 +1,40 @@
+# Issue #275 verification
+
+## Finder on a physical USB drive
+
+Tested on macOS 27 using a mounted FAT32 USB drive. All operations used a disposable test directory; no existing drive files were changed.
+
+An isolated ad-hoc-signed review Finder extension contained the patched binary. The installed MacPacker app remained unchanged and handled the existing extraction/compression URL actions. The review extension was disabled for the before image and enabled for the after image.
+
+| Before: no MacPacker submenu | After: MacPacker submenu available |
+| --- | --- |
+| ![Before](before.png) | ![After](after.png) |
+
+Screenshots are genuine Finder context-menu crops. The cursor and unrelated windows are outside the crop.
+
+- Right-clicking the existing ZIP fixture on the USB drive showed no MacPacker submenu before the fix and showed extraction/compression actions with the review extension enabled.
+- Invoked **Extract Here** through the patched Finder extension. All 3 extracted files matched the fixture ZIP byte-for-byte.
+- Invoked MacPacker's **Compress to "test-file.zip"** on a disposable text file. The resulting ZIP contained the original file byte-for-byte.
+- Removed the review app, extension registration, and disposable USB directory after verification. Confirmed the original installed Finder extension remained enabled.
+
+## Automated verification
+
+The initial home-only implementation failed 3 assertions across the mounted-volume and refresh regression tests. After the fix:
+
+```text
+Test run with 5 tests in 2 suites passed.
+```
+
+The full suite passed before adding the two extra sandbox-home/normalization cases; those extra cases passed in the focused run above:
+
+```text
+Test run with 580 tests in 138 suites passed after 108.639 seconds.
+```
+
+Both MacPacker and MacPacker Store Release builds succeeded with ONLY_ACTIVE_ARCH=NO. The architecture guard checked the resulting bundles:
+
+```text
+15 Mach-O files checked, every one has an arm64 and an x86_64 slice.
+```
+
+Mount/unmount/rename root replacement is covered by the pure regression tests. Physical hot-plug and rename notifications were not manually exercised; the user's external drive was left mounted throughout testing.