Add App Lock settings screen (#1917)

UnitTests/Sources/AppLock/AppLockScreenViewModelTests.swift

@@ -33,6 +33,10 @@ class AppLockScreenViewModelTests: XCTestCase {
         viewModel = AppLockScreenViewModel(appLockService: appLockService)
     }
     
+    override func tearDown() {
+        AppSettings.reset()
+    }
+    
     func testUnlock() async throws {
         // Given a valid PIN code.
         let pinCode = "2023"

UnitTests/Sources/AppLock/AppLockSettingsScreenViewModelTests.swift

@@ -0,0 +1,62 @@
+//
+// Copyright 2022 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import XCTest
+
+@testable import ElementX
+
+@MainActor
+class AppLockSettingsScreenViewModelTests: XCTestCase {
+    var appLockService: AppLockServiceProtocol!
+    var keychainController: KeychainControllerMock!
+    var viewModel: AppLockSettingsScreenViewModelProtocol!
+    
+    var context: AppLockSettingsScreenViewModelType.Context {
+        viewModel.context
+    }
+    
+    override func setUpWithError() throws {
+        AppSettings.reset()
+        let appSettings = AppSettings()
+        appSettings.appLockFlowEnabled = true
+        
+        keychainController = KeychainControllerMock()
+        appLockService = AppLockService(keychainController: keychainController, appSettings: appSettings)
+        
+        viewModel = AppLockSettingsScreenViewModel(appLockService: AppLockServiceMock.mock())
+    }
+    
+    override func tearDown() {
+        AppSettings.reset()
+    }
+
+    func testDisablingShowsAlert() {
+        // Given a fresh screen with the PIN code enabled.
+        let pinCode = "2023"
+        keychainController.pinCodeReturnValue = pinCode
+        keychainController.containsPINCodeReturnValue = true
+        
+        XCTAssertNil(context.alertInfo)
+        XCTAssertTrue(appLockService.isEnabled)
+        
+        // When disabling the PIN code lock.
+        context.send(viewAction: .disable)
+        
+        // Then an alert should be shown before disabling it.
+        XCTAssertNotNil(context.alertInfo)
+        XCTAssertTrue(appLockService.isEnabled)
+    }
+}