Link new device with QR code tweaks. (#5563)

* Hook up Rust's InvalidCheckCode failure to the right state when linking a new device. * Automatically regenerate a new QR code instead of ending the flow when it expires.
2026-10-31 16:24:11 +00:00 · 2026-05-11 14:22:34 +01:00
parent ded86dd66e
commit e235e3ba81
11 changed files with 106 additions and 31 deletions
@@ -51,7 +51,7 @@ class LinkNewDeviceFlowCoordinator: FlowCoordinatorProtocol {
                
                switch action {
                case .linkMobileDevice(let progressPublisher):
-                    presentQRCodeScreen(mode: .linkMobile(progressPublisher))
+                    presentQRCodeScreen(mode: .linkMobile(progressPublisher, flowParameters.userSession.clientProxy))
                case .linkDesktopComputer:
                    presentQRCodeScreen(mode: .linkDesktop(flowParameters.userSession.clientProxy.linkNewDeviceService()))
                case .dismiss:
@@ -39,7 +39,7 @@ enum QRCodeLoginScreenMode {
    /// Configures the screen to link another device by scanning a QR code.
    case linkDesktop(LinkNewDeviceServiceProtocol)
    /// Configures the screen to link another device by showing it a QR code.
-    case linkMobile(LinkNewDeviceService.LinkMobileProgressPublisher)
+    case linkMobile(LinkNewDeviceService.LinkMobileProgressPublisher, ClientProxyProtocol)
 }

 struct QRCodeLoginScreenViewState: BindableState {
@@ -107,7 +107,7 @@ enum QRCodeLoginState: Equatable {
    case displayCode(DisplayCodeState)
    
    /// Initial state where the user can link another device using the shown QR code.
-    case displayQR(UIImage)
+    case displayQR(DisplayQRState)
    /// The user needs to enter the two digit code to confirm the channel is secure
    case confirmCode(CheckCodeState)
    
@@ -171,6 +171,13 @@ enum QRCodeLoginState: Equatable {
        }
    }
    
+    enum DisplayQRState: Equatable {
+        /// The QR code is available and is being shown.
+        case active(UIImage)
+        /// The QR code being shown has expired. We will need to generate a new one.
+        case expired
+    }
+    
    enum DisplayCodeState: Equatable {
        case deviceCode(String)
        case verificationCode(String)
@@ -30,9 +30,9 @@ class QRCodeLoginScreenViewModel: QRCodeLoginScreenViewModelType, QRCodeLoginScr
        let initialViewState: QRCodeLoginState = switch mode {
        case .login: .loginInstructions
        case .linkDesktop: .linkDesktopInstructions
-        case .linkMobile(let progressPublisher):
+        case .linkMobile(let progressPublisher, _):
            switch progressPublisher.value {
-            case .qrReady(let image): .displayQR(image)
+            case .qrReady(let image): .displayQR(.active(image))
            default: .error(.unknown)
            }
        }
@@ -40,7 +40,7 @@ class QRCodeLoginScreenViewModel: QRCodeLoginScreenViewModelType, QRCodeLoginScr
        super.init(initialViewState: .init(state: initialViewState, mode: mode, canSignInManually: canSignInManually))
        setupSubscriptions()
        
-        if case .linkMobile(let progressPublisher) = mode {
+        if case .linkMobile(let progressPublisher, _) = mode {
            listenToDisplayQRProgress(progressPublisher: progressPublisher)
        }
    }
@@ -232,22 +232,49 @@ class QRCodeLoginScreenViewModel: QRCodeLoginScreenViewModelType, QRCodeLoginScr
            }
    }
    
+    private func regenerateQRCode() async {
+        guard case .linkMobile(_, let clientProxy) = state.mode else {
+            fatalError("Cannot display a QR code in this mode.")
+        }
+        
+        let linkNewDeviceService = clientProxy.linkNewDeviceService()
+        let progressPublisher = linkNewDeviceService.linkMobileDevice()
+        
+        do {
+            async let minimumDelay = Task.sleep(for: .seconds(1)) // To show the spinner for long enough so there isn't a flicker.
+            async let qrReadyProgress = progressPublisher.values
+                .first { progress in
+                    switch progress {
+                    case .qrReady: true
+                    default: false
+                    }
+                }
+
+            guard case .qrReady(let image) = try await (qrReadyProgress, minimumDelay).0 else {
+                state.state = .error(.unknown)
+                return
+            }
+
+            state.state = .displayQR(.active(image))
+        } catch let error as QRCodeLoginError {
+            handleError(error)
+        } catch {
+            handleError(.unknown)
+        }
+        
+        listenToDisplayQRProgress(progressPublisher: progressPublisher)
+    }
+    
    private func sendCheckCode() async {
        guard case let .confirmCode(.inputCode(checkCodeSender)) = state.state else {
            fatalError("Attempting to check code from the wrong state.")
        }
        
+        state.state = .confirmCode(.sendingCode)
+        
        let stringValue = state.bindings.checkCodeInput
        let code = UInt8(stringValue) ?? 0
        
-        if !checkCodeSender.validate(checkCode: code) {
-            MXLog.error("Invalid code entered.")
-            state.state = .confirmCode(.invalidCode)
-            return
-        }
-        
-        state.state = .confirmCode(.sendingCode)
-        
        do {
            MXLog.info("Valid code entered, sending.")
            try await checkCodeSender.send(code: code)
@@ -291,10 +318,15 @@ class QRCodeLoginScreenViewModel: QRCodeLoginScreenViewModelType, QRCodeLoginScr
            state.state = .error(.cancelled)
        case .connectionInsecure:
            state.state = .error(.connectionNotSecure)
+        case .invalidCheckCode:
+            state.state = .confirmCode(.invalidCode)
        case .declined:
            state.state = .error(.declined)
        case .linkingNotSupported:
            state.state = .error(.linkingNotSupported)
+        case .expired where state.state.isDisplayQR:
+            state.state = .displayQR(.expired)
+            Task { await regenerateQRCode() }
        case .expired:
            state.state = .error(.expired)
        case .slidingSyncNotAvailable:
@@ -207,19 +207,26 @@ struct QRCodeLoginScreen: View {
    
    @ViewBuilder
    private var displayQRContent: some View {
-        if case let .displayQR(image) = context.viewState.state {
+        if case let .displayQR(qrState) = context.viewState.state {
            FullscreenDialog(topPadding: 24, horizontalPadding: 24) {
                VStack(spacing: 32) {
                    TitleAndIcon(title: L10n.screenLinkNewDeviceMobileTitle(InfoPlistReader.main.productionAppName),
                                 icon: \.takePhotoSolid,
                                 iconStyle: .default)
                    
-                    Image(uiImage: image)
-                        .interpolation(.none) // to stop it getting blurred
-                        .resizable()
-                        .scaledToFit()
-                        .frame(width: 200, height: 200)
-                        .accessibilityLabel(L10n.a11yQrCode)
+                    switch qrState {
+                    case .active(let image):
+                        Image(uiImage: image)
+                            .interpolation(.none) // to stop it getting blurred
+                            .resizable()
+                            .scaledToFit()
+                            .frame(width: 200, height: 200)
+                            .accessibilityLabel(L10n.a11yQrCode)
+                    case .expired:
+                        ProgressView()
+                            .controlSize(.large)
+                            .frame(width: 200, height: 200)
+                    }
                    
                    SFNumberedListView(items: context.viewState.instructions.linkMobileItems)
                }
@@ -337,7 +344,8 @@ struct QRCodeLoginScreen_Previews: PreviewProvider, TestablePreview {
    static let deviceNotSignedInStateViewModel = QRCodeLoginScreenViewModel.mock(state: .scan(.scanFailed(.deviceNotSignedIn)))
    
    /// Showing
-    static let showingStateViewModel = QRCodeLoginScreenViewModel.mock(state: .displayQR(LinkNewDeviceServiceMock.mockQRCodeImage))
+    static let showingStateViewModel = QRCodeLoginScreenViewModel.mock(state: .displayQR(.active(LinkNewDeviceServiceMock.mockQRCodeImage)))
+    static let showingExpiredStateViewModel = QRCodeLoginScreenViewModel.mock(state: .displayQR(.expired))
    
    // Displaying codes
    static let deviceCodeStateViewModel = QRCodeLoginScreenViewModel.mock(state: .displayCode(.deviceCode("12")))
@@ -369,6 +377,8 @@ struct QRCodeLoginScreen_Previews: PreviewProvider, TestablePreview {
        
        ElementNavigationStack { QRCodeLoginScreen(context: showingStateViewModel.context) }
            .previewDisplayName("Showing")
+        ElementNavigationStack { QRCodeLoginScreen(context: showingExpiredStateViewModel.context) }
+            .previewDisplayName("Showing expired")
        
        ElementNavigationStack { QRCodeLoginScreen(context: deviceCodeStateViewModel.context) }
            .previewDisplayName("Device code")
@@ -111,6 +111,7 @@ enum QRCodeLoginError: Error, Equatable {
    case providerNotAllowed(scannedProvider: String, allowedProviders: [String])
    case cancelled
    case connectionInsecure
+    case invalidCheckCode
    case declined
    case linkingNotSupported
    case expired
@@ -195,8 +195,10 @@ extension LinkNewDeviceService.LinkDesktopProgress: CustomStringConvertible {
 private extension QRCodeLoginError {
    init(rustError: HumanQrGrantLoginError) {
        self = switch rustError {
-        case .InvalidCheckCode, .ConnectionInsecure:
+        case .ConnectionInsecure:
            .connectionInsecure
+        case .InvalidCheckCode:
+            .invalidCheckCode
        case .UnsupportedProtocol:
            .linkingNotSupported
        case .Expired, .NotFound, .DeviceNotFound:
@@ -227,13 +229,6 @@ class CheckCodeSenderProxy: Equatable {
    func send(code: UInt8) async throws {
        try await underlyingSender.send(code: code)
    }
-    
-    /// Bypassed for now whilst we wait for an SDK update (however its worth noting that
-    /// things should still fail if the wrong code is provided, just not necessarily with
-    /// the right error being shown). https://github.com/matrix-org/matrix-rust-sdk/pull/5957
-    func validate(checkCode: UInt8) -> Bool {
-        true
-    }
 }

 extension UIImage {
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:35b2338f432dd2d65581f94680382a33af87881bfd36e2a426a96f879ed1d93f
+size 119474
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3f34b4d5fb95d223b8b1cf850fe74fc75d031da0a7f0a359b5a4c3e29fa83669
+size 142744
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c86cc8592649e4d3e65a6632fd02756455ffd48bbdc35b12d7db5a8ba147c988
+size 70650
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2bbc55c8ae626a1e652864927dfa2eab2860c85dca9372cca73e0af982d7ca41
+size 96693
@@ -9,6 +9,7 @@
 import Combine
@testable import ElementX
 import MatrixRustSDKMocks
+import SwiftUI
 import Testing

@MainActor
@@ -18,6 +19,7 @@ struct QRCodeLoginScreenViewModelTests {
    var qrLoginProgressSubject: CurrentValueSubject<QRLoginProgress, AuthenticationServiceError>!
    var qrCodeLoginService: QRCodeLoginServiceMock!
    
+    var regeneratedQRCodeImage: UIImage!
    var linkMobileProgressSubject: CurrentValueSubject<LinkNewDeviceService.LinkMobileProgress, QRCodeLoginError>!
    var linkDesktopProgressSubject: CurrentValueSubject<LinkNewDeviceService.LinkDesktopProgress, QRCodeLoginError>!
    var linkNewDeviceService: LinkNewDeviceServiceMock!
@@ -202,6 +204,17 @@ struct QRCodeLoginScreenViewModelTests {
        try await deferredAction.fulfill()
    }
    
+    @Test
+    mutating func linkMobileDeviceQRCodeExpiry() async throws {
+        setup(mode: .linkMobile)
+        #expect(context.viewState.state.isDisplayQR)
+        
+        let deferred = deferFulfillment(context.$viewState, keyPath: \.state, transitionValues: [.displayQR(.expired),
+                                                                                                 .displayQR(.active(regeneratedQRCodeImage))])
+        linkMobileProgressSubject.send(completion: .failure(.expired))
+        try await deferred.fulfill()
+    }
+    
    // MARK: - Helpers
    
    private mutating func setup(mode: Mode) {
@@ -214,6 +227,11 @@ struct QRCodeLoginScreenViewModelTests {
        linkNewDeviceService = LinkNewDeviceServiceMock(.init(linkMobileProgressPublisher: linkMobileProgressSubject.asCurrentValuePublisher(),
                                                              linkDesktopProgressPublisher: linkDesktopProgressSubject.asCurrentValuePublisher()))
        
+        regeneratedQRCodeImage = LinkNewDeviceServiceMock.mockQRCodeImage
+        let clientProxy = ClientProxyMock(.init())
+        clientProxy.linkNewDeviceServiceReturnValue = LinkNewDeviceServiceMock(.init(linkMobileProgressPublisher: .init(.qrReady(regeneratedQRCodeImage)),
+                                                                                     linkDesktopProgressPublisher: .init(.starting)))
+        
        let screenMode: QRCodeLoginScreenMode
        switch mode {
        case .login:
@@ -221,7 +239,7 @@ struct QRCodeLoginScreenViewModelTests {
        case .linkDesktop:
            screenMode = .linkDesktop(linkNewDeviceService)
        case .linkMobile:
-            screenMode = .linkMobile(linkNewDeviceService.linkMobileDevice())
+            screenMode = .linkMobile(linkNewDeviceService.linkMobileDevice(), clientProxy)
        }
        
        appMediator = AppMediatorMock.default