Find ExtensionKit extensions in Extensions/

Sources/Models/AppBundle.swift

@@ -117,13 +117,12 @@ public struct AppBundle: Sendable, Identifiable, Hashable, Equatable {
     }
 
     private func loadExtensions() -> Set<AppBundle> {
-        let pluginsURL = fileURL.appendingPathComponent("PlugIns")
-        guard let contents = try? FileManager.default.contentsOfDirectory(
-            at: pluginsURL,
-            includingPropertiesForKeys: nil,
-            options: [.skipsHiddenFiles]
-        ) else {
-            return []
+        let contents = ["PlugIns", "Extensions"].flatMap { folder in
+            (try? FileManager.default.contentsOfDirectory(
+                at: fileURL.appendingPathComponent(folder),
+                includingPropertiesForKeys: nil,
+                options: [.skipsHiddenFiles]
+            )) ?? []
         }
         let extensions = contents
             .filter { $0.pathExtension.lowercased() == "appex" }

Tests/SideSignTests/AppBundleTests.swift

@@ -0,0 +1,129 @@
+import Foundation
+import Testing
+@testable import SideSign
+
+@Suite("App Bundle Extension Discovery Tests")
+struct AppBundleTests {
+
+    @Test
+    func discoversExtensionsFromBothDirectoriesAndSkipsInvalidEntries() throws {
+        let fixture = try BundleFixture()
+        defer { fixture.remove() }
+
+        try fixture.addBundle(named: "Plugin.appex", in: "PlugIns", identifier: "com.example.plugin")
+        try fixture.addBundle(named: "Extension.appex", in: "Extensions", identifier: "com.example.extension")
+        try fixture.addBundle(named: "Uppercase.APPEX", in: "Extensions", identifier: "com.example.uppercase")
+        try fixture.addBundle(named: ".Hidden.appex", in: "Extensions", identifier: "com.example.hidden")
+        try fixture.addBundle(named: "Invalid.appex", in: "Extensions", identifier: nil)
+        try fixture.addBundle(named: "NotAnExtension.bundle", in: "Extensions", identifier: "com.example.bundle")
+        try fixture.addFile(named: "File.appex", in: "Extensions")
+        try fixture.addBundle(named: "NestedChild.appex", in: "Extensions/Nested", identifier: "com.example.nested")
+
+        let app = try #require(AppBundle(fileURL: fixture.appURL))
+        let discovered = app.appExtensions
+
+        #expect(Set(discovered.map(\.bundleIdentifier)) == [
+            "com.example.extension",
+            "com.example.plugin",
+            "com.example.uppercase"
+        ])
+        #expect(app.allAppBundles.map(\.bundleIdentifier) == [
+            "com.example.app",
+            "com.example.extension",
+            "com.example.plugin",
+            "com.example.uppercase"
+        ])
+        #expect(app.appBundle(withBundleIdentifier: "com.example.plugin")?.fileURL.lastPathComponent == "Plugin.appex")
+        #expect(app.appBundle(withBundleIdentifier: "com.example.extension")?.fileURL.lastPathComponent == "Extension.appex")
+        #expect(app.appBundle(withBundleIdentifier: "com.example.nested") == nil)
+        #expect(app.appBundle(withBundleIdentifier: "com.example.app")?.fileURL == fixture.appURL)
+    }
+
+    @Test
+    func discoversExtensionsWhenPlugInsDirectoryIsMissing() throws {
+        let fixture = try BundleFixture()
+        defer { fixture.remove() }
+        try fixture.addBundle(named: "Extension.appex", in: "Extensions", identifier: "com.example.extension")
+
+        let app = try #require(AppBundle(fileURL: fixture.appURL))
+
+        #expect(app.appExtensions.map(\.bundleIdentifier) == ["com.example.extension"])
+    }
+
+    @Test
+    func discoversExtensionsWhenExtensionsDirectoryIsMissing() throws {
+        let fixture = try BundleFixture()
+        defer { fixture.remove() }
+        try fixture.addBundle(named: "Plugin.appex", in: "PlugIns", identifier: "com.example.plugin")
+
+        let app = try #require(AppBundle(fileURL: fixture.appURL))
+
+        #expect(app.appExtensions.map(\.bundleIdentifier) == ["com.example.plugin"])
+    }
+
+    @Test
+    func returnsNoExtensionsWhenNeitherDirectoryExists() throws {
+        let fixture = try BundleFixture()
+        defer { fixture.remove() }
+
+        let app = try #require(AppBundle(fileURL: fixture.appURL))
+
+        #expect(app.appExtensions.isEmpty)
+    }
+
+    @Test(arguments: ["PlugIns", "Extensions"])
+    func unreadableDirectoryDoesNotHideOtherDirectory(unreadableDirectory: String) throws {
+        let fixture = try BundleFixture()
+        defer { fixture.remove() }
+        let readableDirectory = unreadableDirectory == "PlugIns" ? "Extensions" : "PlugIns"
+        try fixture.addFile(named: unreadableDirectory, in: nil)
+        try fixture.addBundle(named: "Extension.appex", in: readableDirectory, identifier: "com.example.extension")
+
+        let app = try #require(AppBundle(fileURL: fixture.appURL))
+
+        #expect(app.appExtensions.map(\.bundleIdentifier) == ["com.example.extension"])
+    }
+}
+
+private struct BundleFixture {
+    let rootURL: URL
+    let appURL: URL
+
+    init() throws {
+        let fileManager = FileManager.default
+        rootURL = fileManager.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        appURL = rootURL.appendingPathComponent("Sample.app")
+        try fileManager.createDirectory(at: appURL, withIntermediateDirectories: true)
+        try Self.writeInfoPlist(to: appURL, identifier: "com.example.app")
+    }
+
+    func addBundle(named name: String, in directoryName: String, identifier: String?) throws {
+        let directoryURL = appURL.appendingPathComponent(directoryName)
+        let bundleURL = directoryURL.appendingPathComponent(name)
+        try FileManager.default.createDirectory(at: bundleURL, withIntermediateDirectories: true)
+        if let identifier {
+            try Self.writeInfoPlist(to: bundleURL, identifier: identifier)
+        }
+    }
+
+    func addFile(named name: String, in directoryName: String?) throws {
+        let directoryURL = directoryName.map { appURL.appendingPathComponent($0) } ?? appURL
+        try FileManager.default.createDirectory(at: directoryURL, withIntermediateDirectories: true)
+        try Data().write(to: directoryURL.appendingPathComponent(name))
+    }
+
+    func remove() {
+        try? FileManager.default.removeItem(at: rootURL)
+    }
+
+    private static func writeInfoPlist(to bundleURL: URL, identifier: String) throws {
+        let plist: [String: Any] = [
+            "CFBundleIdentifier": identifier,
+            "CFBundleName": bundleURL.deletingPathExtension().lastPathComponent,
+            "CFBundleShortVersionString": "1.0",
+            "CFBundleVersion": "1"
+        ]
+        let data = try PropertyListSerialization.data(fromPropertyList: plist, format: .xml, options: 0)
+        try data.write(to: bundleURL.appendingPathComponent("Info.plist"))
+    }
+}

Tests/SideSignTests/SideSignTests.swift

@@ -6,6 +6,7 @@
 //  Copyright © 2026 SideSign. All rights reserved.
 //
 
+import Foundation
 import Testing
 @testable import SideSign
 import CodeSignKit