Debounce PIN entry to show the last digit before submitting. (#2017)

ElementX/Sources/Screens/AppLock/AppLockScreen/AppLockScreenModels.swift

@@ -60,8 +60,6 @@ enum AppLockScreenAlertType {
 }
 
 enum AppLockScreenViewAction {
-    /// Attempt to unlock the app with the supplied PIN code.
-    case submitPINCode
     /// Clears the PIN code after a failure animation.
     case clearPINCode
     /// The user didn't heed the warnings and can't remember their PIN.

ElementX/Sources/Screens/AppLock/AppLockScreen/AppLockScreenViewModel.swift

@@ -36,6 +36,16 @@ class AppLockScreenViewModel: AppLockScreenViewModelType, AppLockScreenViewModel
             .weakAssign(to: \.state.numberOfPINAttempts, on: self)
             .store(in: &cancellables)
         
+        context.$viewState
+            .map(\.bindings.pinCode)
+            .removeDuplicates()
+            .debounce(for: 0.05, scheduler: DispatchQueue.main) // Allow the last digit to be briefly shown
+            .sink { [weak self] pinCode in
+                guard pinCode.count == 4 else { return }
+                self?.submit(pinCode)
+            }
+            .store(in: &cancellables)
+        
         showForceLogoutAlertIfNeeded()
     }
     
@@ -45,8 +55,6 @@ class AppLockScreenViewModel: AppLockScreenViewModelType, AppLockScreenViewModel
         MXLog.info("View model: received view action: \(viewAction)")
         
         switch viewAction {
-        case .submitPINCode:
-            submitPINCode()
         case .clearPINCode:
             state.bindings.pinCode = ""
         case .forgotPIN:
@@ -56,8 +64,8 @@ class AppLockScreenViewModel: AppLockScreenViewModelType, AppLockScreenViewModel
     
     // MARK: - Private
     
-    private func submitPINCode() {
+    private func submit(_ pinCode: String) {
-        guard appLockService.unlock(with: state.bindings.pinCode) else {
+        guard appLockService.unlock(with: pinCode) else {
             handleInvalidPIN()
             return
         }

ElementX/Sources/Screens/AppLock/AppLockScreen/View/AppLockScreen.swift

@@ -49,10 +49,6 @@ struct AppLockScreen: View {
                     .accessibilityValue(L10n.a11yDigitsEntered(context.viewState.numberOfDigitsEntered))
                 
                 AppLockScreenPINKeypad(pinCode: $context.pinCode)
-                    .onChange(of: context.pinCode) { newValue in
-                        guard newValue.count == 4 else { return }
-                        context.send(viewAction: .submitPINCode)
-                    }
             }
         } bottomContent: {
             Button(L10n.screenAppLockForgotPin) {

ElementX/Sources/Screens/AppLock/AppLockSetupPINScreen/AppLockSetupPINScreenModels.swift

@@ -88,8 +88,6 @@ enum AppLockSetupPINScreenAlertType {
 }
 
 enum AppLockSetupPINScreenViewAction {
-    /// Confirm the entered PIN.
-    case submitPINCode
     /// Stop entering a PIN.
     case cancel
 }

ElementX/Sources/Screens/AppLock/AppLockSetupPINScreen/AppLockSetupPINScreenViewModel.swift

@@ -38,6 +38,16 @@ class AppLockSetupPINScreenViewModel: AppLockSetupPINScreenViewModelType, AppLoc
         appLockService.numberOfPINAttempts
             .weakAssign(to: \.state.numberOfUnlockAttempts, on: self)
             .store(in: &cancellables)
+        
+        context.$viewState
+            .map(\.bindings.pinCode)
+            .removeDuplicates()
+            .debounce(for: 0.1, scheduler: DispatchQueue.main) // Show the last digit for long enough to be read.
+            .sink { [weak self] pinCode in
+                guard pinCode.count == 4 else { return }
+                self?.submit(pinCode)
+            }
+            .store(in: &cancellables)
     }
     
     // MARK: - Public
@@ -46,8 +56,6 @@ class AppLockSetupPINScreenViewModel: AppLockSetupPINScreenViewModelType, AppLoc
         MXLog.info("View model: received view action: \(viewAction)")
         
         switch viewAction {
-        case .submitPINCode:
-            submitPINCode()
         case .cancel:
             actionsSubject.send(.cancel)
         }
@@ -56,7 +64,7 @@ class AppLockSetupPINScreenViewModel: AppLockSetupPINScreenViewModelType, AppLoc
     // MARK: - Private
     
     /// Handle the entered PIN code.
-    private func submitPINCode() {
+    private func submit(_ pinCode: String) {
         switch state.mode {
         case .create:
             createPIN()

ElementX/Sources/Screens/AppLock/AppLockSetupPINScreen/View/AppLockSetupPINScreen.swift

@@ -43,10 +43,6 @@ struct AppLockSetupPINScreen: View {
                 PINTextField(pinCode: $context.pinCode,
                              isSecure: context.viewState.mode == .unlock)
                     .focused($textFieldFocus)
-                    .onChange(of: context.pinCode) { newValue in
-                        guard newValue.count == 4 else { return }
-                        context.send(viewAction: .submitPINCode)
-                    }
             }
             .padding(.horizontal, 16)
             .padding(.top, UIConstants.iconTopPaddingToNavigationBar)

UnitTests/Sources/AppLock/AppLockScreenViewModelTests.swift

@@ -48,7 +48,6 @@ class AppLockScreenViewModelTests: XCTestCase {
         // When entering it on the lock screen.
         let deferred = deferFulfillment(viewModel.actions) { $0 == .appUnlocked }
         viewModel.context.pinCode = pinCode
-        context.send(viewAction: .submitPINCode)
         let result = try await deferred.fulfill()
         
         // The app should become unlocked.
@@ -76,8 +75,10 @@ class AppLockScreenViewModelTests: XCTestCase {
         XCTAssertNil(context.alertInfo, "No alert should be shown yet.")
         
         // When entering it on the lock screen.
+        var deferred = deferFulfillment(context.$viewState) { $0.numberOfPINAttempts == 1 }
         viewModel.context.pinCode = pinCode
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
+        context.send(viewAction: .clearPINCode) // Simulate the animation completion
         
         // Then a failed attempt should be shown.
         XCTAssertEqual(context.viewState.numberOfPINAttempts, 1, "A failed attempt should have been recorded.")
@@ -85,8 +86,14 @@ class AppLockScreenViewModelTests: XCTestCase {
         XCTAssertNil(context.alertInfo, "No alert should be shown yet.")
         
         // When entering twice more
-        context.send(viewAction: .submitPINCode)
+        deferred = deferFulfillment(context.$viewState) { $0.numberOfPINAttempts == 2 }
-        context.send(viewAction: .submitPINCode)
+        viewModel.context.pinCode = pinCode
+        try await deferred.fulfill()
+        context.send(viewAction: .clearPINCode) // Simulate the animation completion
+        deferred = deferFulfillment(context.$viewState) { $0.numberOfPINAttempts == 3 }
+        viewModel.context.pinCode = pinCode
+        try await deferred.fulfill()
+        context.send(viewAction: .clearPINCode) // Simulate the animation completion
         
         // Then an alert should be shown
         XCTAssertEqual(context.viewState.numberOfPINAttempts, 3, "All the attempts should have been recorded.")
@@ -94,14 +101,15 @@ class AppLockScreenViewModelTests: XCTestCase {
         XCTAssertEqual(context.alertInfo?.id, .forcedLogout, "An alert should now be shown.")
     }
     
-    func testForceQuitRequiresLogout() {
+    func testForceQuitRequiresLogout() async throws {
         // Given an app with a PIN set where the user attempted to unlock 3 times.
         keychainController.pinCodeReturnValue = "2023"
         keychainController.containsPINCodeBiometricStateReturnValue = false
         appSettings.appLockNumberOfPINAttempts = 2
         XCTAssertNil(context.alertInfo)
+        let deferred = deferFulfillment(context.$viewState) { $0.numberOfPINAttempts == 3 }
         viewModel.context.pinCode = "0000"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         XCTAssertEqual(appSettings.appLockNumberOfPINAttempts, 3, "The app should have 3 failed attempts before the force quit.")
         XCTAssertEqual(context.alertInfo?.id, .forcedLogout, "The app should be showing the alert before the force quit.")
         

UnitTests/Sources/AppLock/AppLockSetupPINScreenViewModelTests.swift

@@ -44,7 +44,6 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         // When entering an new PIN.
         let createDeferred = deferFulfillment(context.$viewState, message: "A valid PIN needs confirming.") { $0.mode == .confirm }
         context.pinCode = "2023"
-        context.send(viewAction: .submitPINCode)
         try await createDeferred.fulfill()
         
         // Then the screen should transition to the confirm mode.
@@ -53,7 +52,6 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         // When re-entering that PIN.
         let confirmDeferred = deferFulfillment(viewModel.actions, message: "The screen should be finished.") { $0 == .complete }
         context.pinCode = "2023"
-        context.send(viewAction: .submitPINCode)
         
         // Then the screen should signal it is complete.
         try await confirmDeferred.fulfill()
@@ -66,8 +64,9 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         XCTAssertNil(context.alertInfo, "There shouldn't be an alert to begin with.")
         
         // When entering a weak PIN on the blocklist.
+        let deferred = deferFulfillment(context.$viewState) { $0.bindings.alertInfo != nil }
         context.pinCode = "0000"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         
         // Then the PIN should be rejected and the user alerted.
         XCTAssertEqual(context.alertInfo?.id, .weakPIN, "The weak PIN should be rejected.")
@@ -82,25 +81,29 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         
         let createDeferred = deferFulfillment(context.$viewState, message: "A valid PIN needs confirming.") { $0.mode == .confirm }
         context.pinCode = "2023"
-        context.send(viewAction: .submitPINCode)
         try await createDeferred.fulfill()
         XCTAssertEqual(context.viewState.mode, .confirm, "The mode should transition to confirmation.")
         XCTAssertEqual(context.viewState.numberOfConfirmAttempts, 0, "The mode should start with zero attempts.")
         XCTAssertNil(context.alertInfo, "There shouldn't be an alert after a valid initial PIN.")
         
         // When entering the new PIN incorrectly
+        var deferred = deferFulfillment(context.$viewState) { $0.numberOfConfirmAttempts == 1 }
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         
         // Then the user should be alerted.
         XCTAssertEqual(context.viewState.numberOfConfirmAttempts, 1, "The mismatch should be counted.")
         XCTAssertEqual(context.alertInfo?.id, .pinMismatch, "A PIN mismatch should be rejected.")
         
-        // When repeating this twice more.
+        // When dismissing the alert and repeating twice more.
+        context.alertInfo?.primaryButton.action?()
+        deferred = deferFulfillment(context.$viewState) { $0.numberOfConfirmAttempts == 2 }
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
+        context.alertInfo?.primaryButton.action?()
+        deferred = deferFulfillment(context.$viewState) { $0.numberOfConfirmAttempts == 3 }
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         XCTAssertEqual(context.viewState.numberOfConfirmAttempts, 3, "All the mismatches should be counted.")
         XCTAssertEqual(context.alertInfo?.id, .pinMismatch, "A PIN mismatch should be rejected.")
         
@@ -120,7 +123,6 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         // When entering the configured PIN.
         let deferred = deferFulfillment(viewModel.actions, message: "The screen should be finished.") { $0 == .complete }
         context.pinCode = pinCode
-        context.send(viewAction: .submitPINCode)
         
         // Then the screen should signal it is complete.
         try await deferred.fulfill()
@@ -137,8 +139,10 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         XCTAssertFalse(context.viewState.isLoggingOut, "The view should not start disabled.")
         
         // When entering a different PIN.
+        var deferred = deferFulfillment(context.$viewState, keyPath: \.bindings.pinCode, transitionValues: ["", "2024", ""],
+                                        message: "The PIN should be entered and then cleared by the view model.")
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         
         // Then the PIN should be rejected and the user notified.
         XCTAssertEqual(context.viewState.numberOfUnlockAttempts, 1, "An invalid attempt should be counted.")
@@ -146,10 +150,14 @@ class AppLockSetupPINScreenViewModelTests: XCTestCase {
         XCTAssertFalse(context.viewState.isLoggingOut, "The view should still work.")
         
         // When entering the same incorrect PIN twice more
+        deferred = deferFulfillment(context.$viewState, keyPath: \.bindings.pinCode, transitionValues: ["", "2024", ""],
+                                    message: "The PIN should be entered and then cleared by the view model.")
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
+        deferred = deferFulfillment(context.$viewState, keyPath: \.bindings.pinCode, transitionValues: ["", "2024", ""],
+                                    message: "The PIN should be entered and then cleared by the view model.")
         context.pinCode = "2024"
-        context.send(viewAction: .submitPINCode)
+        try await deferred.fulfill()
         
         // Then the user should be alerted that they're being signed out.
         XCTAssertEqual(context.viewState.numberOfUnlockAttempts, 3, "All invalid attempts should be counted.")

changelog.d/2010.bugfix

@@ -0,0 +1 @@
+Make sure the last digit is visible when entering a PIN.