feat(macos): add macOS permissions service for Input Monitoring, Local Network, and Notifications (#21)

* feat(macos): add macOS permissions service for Input Monitoring, Local Network, and Notifications Add MacOSPermissionsService (Dart) + native MethodChannel handler (Swift) for macOS-specific permissions not covered by permission_handler: - Input Monitoring (CGPreflightListenEventAccess / CGRequestListenEventAccess) for global PTT via Event Tap - Local Network Privacy prompt (NWBrowser for _ts3._tcp, macOS 15+) - Notifications (UNUserNotificationCenter authorization) Trace: SRS-198, SRS-297, SRS-300, SysRS-166, SDD-091 Changes: - Info.plist: add NSBonjourServices array with _ts3._tcp - macos_permissions_service.dart: Dart service with MethodChannel, ValueNotifier states, PTT capability derivation (L0Focused / L1MacOSEventTap), non-macOS short-circuit - MainFlutterWindow.swift: native handler registered as FlutterPlugin, Input Monitoring check/request/polling, NWBrowser trigger with denial detection, UNUserNotificationCenter request - main.dart: wire service into bootstrap lifecycle, listen for PTT capability changes from Input Monitoring state - macos_permissions_service_test.dart: 17 unit tests covering inbound state changes, outbound calls, lifecycle, error handling, platform behavior (179/179 full suite pass) * fix(macos): keep permissions capability state live
2026-06-05 14:26:11 +09:00
parent 2902a8bcd5
commit 12e3a1f4ee
5 changed files with 1344 additions and 1 deletions
@@ -23,6 +23,7 @@ import 'services/audio_lifecycle_service.dart';
 import 'services/channel_join_error_mapper.dart';
 import 'services/connection_phase_state.dart';
 import 'services/ios_permissions_service.dart';
+import 'services/macos_permissions_service.dart';
 import 'services/prefetch_debouncer.dart';
 import 'services/snapshot_state_mapper.dart';
 import 'services/ts3_server_link.dart';
@@ -378,6 +379,12 @@ class _BetaHomeState extends State<_BetaHome> with WidgetsBindingObserver {
  final AndroidPermissionsService _androidPermissions =
      AndroidPermissionsService();
  final IosPermissionsService _iosPermissions = IosPermissionsService();
+  // SRS-198 / SRS-297 / SRS-300: macOS Input Monitoring, Local Network,
+  // and Notifications permission service. On non-macOS hosts the service
+  // short-circuits to "granted" / "unsupported" and never wires the
+  // MethodChannel.
+  final MacOSPermissionsService _macOSPermissions =
+      MacOSPermissionsService();
  final UiPreferencesService _uiPreferences = const UiPreferencesService();

  @override
@@ -399,6 +406,16 @@ class _BetaHomeState extends State<_BetaHome> with WidgetsBindingObserver {
    _iosPermissions.recordAudioState.addListener(
      _onRecordAudioPermissionChanged,
    );
+    // SRS-198 / SRS-297 / SRS-300: start macOS permission service.
+    // On non-macOS this is a no-op. On macOS, it checks Input
+    // Monitoring state and begins polling for changes so the PTT
+    // capability badge upgrades from L0Focused → L1MacOSEventTap
+    // when the user grants the permission in System Settings.
+    _macOSPermissions.start();
+    _macOSPermissions.pttCapabilityState.addListener(
+      _onMacOSPttCapabilityChanged,
+    );
+    _macOSPermissions.checkInitialStates();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      unawaited(_requestRecordAudioOnStartup());
    });
@@ -498,6 +515,28 @@ class _BetaHomeState extends State<_BetaHome> with WidgetsBindingObserver {
    }
  }

+  /// SRS-198 / SRS-297 / SRS-300 / SDD-091: React to macOS Input
+  /// Monitoring state changes by updating the PTT capability level.
+  /// When the macOS permissions service detects that Input Monitoring
+  /// has been granted (via polling), it emits `L1MacOSEventTap` which
+  /// overrides the bridge-emitted `L0Focused` default.
+  void _onMacOSPttCapabilityChanged() {
+    final level = _macOSPermissions.pttCapabilityState.value;
+    // Only override if the macOS service has a resolved state
+    // different from the current bridge-emitted level, and only
+    // on macOS.
+    if (_isMacOS && level != _pttLevel) {
+      setState(() {
+        _pttLevel = level;
+        if (level == 'L1MacOSEventTap') {
+          _pttBackendId = 'macos-event-tap';
+        } else if (level == 'L0Focused') {
+          _pttBackendId = 'focused';
+        }
+      });
+    }
+  }
+
  Future<void> _clearPermissionHardMute() async {
    if (!_hardMuteByPermission || _permissionHardMuteClearInFlight) return;
    _permissionHardMuteClearInFlight = true;
@@ -936,11 +975,16 @@ class _BetaHomeState extends State<_BetaHome> with WidgetsBindingObserver {
    _iosPermissions.recordAudioState.removeListener(
      _onRecordAudioPermissionChanged,
    );
+    // SRS-198 / SRS-297: detach macOS permission listeners.
+    _macOSPermissions.pttCapabilityState.removeListener(
+      _onMacOSPttCapabilityChanged,
+    );
    // SDD-106: detach the Kotlin -> Dart MethodChannel handler so a
    // late invokeMethod from the platform side cannot land on this
    // disposed state.
    _androidPermissions.stop();
    _iosPermissions.stop();
+    _macOSPermissions.stop();
    super.dispose();
  }

@@ -0,0 +1,500 @@
+/// macOS permission integration for Input Monitoring, Local Network,
+/// and Notifications.
+///
+/// Trace:
+/// - SRS-198 (Push-to-talk system permission acquisition).
+/// - SRS-297 / SRS-300 (Input Monitoring for global PTT on macOS).
+/// - SysRS-166 (Desktop notifications).
+/// - SDD-091 (PTT capability badge — live capability level).
+///
+/// Responsibilities:
+///  * Subscribe to the Swift-side `MethodChannel`
+///    `app.chanora/macos_permissions` for inbound state-change
+///    invocations emitted by the native handler in
+///    `MainFlutterWindow.swift` (Swift → Dart).
+///  * Provide imperative Dart → Swift entry points for checking and
+///    requesting Input Monitoring, triggering the Local Network
+///    prompt, and requesting notification authorization.
+///  * Expose the latest resolved states as [ValueListenable] so UI
+///    surfaces (PTT capability badge, permission banners, connection
+///    error messages) can react without polling.
+///
+/// ## Non-macOS short-circuit
+///
+/// On Android / iOS / Linux / Windows / web, none of these macOS-
+/// specific permissions exist. The MethodChannel is therefore never
+/// constructed off-macOS. Each state listenable stays at its default
+/// "granted" / "not needed" value so all consumers become no-ops.
+///
+/// ## No global statics
+///
+/// Following the pattern established by `AndroidPermissionsService`
+/// (SDD-106) and `BackIntentService` (SDD-028), this class is
+/// constructor-injected. The host app instantiates one instance at
+/// startup and passes it through the widget tree.
+library;
+
+import 'dart:async';
+import 'dart:developer' as developer;
+import 'dart:io' show Platform;
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+
+// ---------------------------------------------------------------------------
+// Channel constants
+// ---------------------------------------------------------------------------
+
+/// MethodChannel name shared with Swift `MacOSPermissionsHandler`.
+@visibleForTesting
+const String macOSPermissionsChannelName =
+    'app.chanora/macos_permissions';
+
+// Outbound (Dart → Swift) method names.
+@visibleForTesting
+const String methodCheckInputMonitoring = 'checkInputMonitoring';
+@visibleForTesting
+const String methodRequestInputMonitoring = 'requestInputMonitoring';
+@visibleForTesting
+const String methodOpenInputMonitoringSettings =
+    'openInputMonitoringSettings';
+@visibleForTesting
+const String methodTriggerLocalNetworkPrompt = 'triggerLocalNetworkPrompt';
+@visibleForTesting
+const String methodCheckLocalNetwork = 'checkLocalNetwork';
+@visibleForTesting
+const String methodRequestNotifications = 'requestNotifications';
+@visibleForTesting
+const String methodCheckNotifications = 'checkNotifications';
+
+// Inbound (Swift → Dart) method names.
+@visibleForTesting
+const String methodInputMonitoringStateChanged =
+    'inputMonitoringStateChanged';
+@visibleForTesting
+const String methodLocalNetworkStateChanged = 'localNetworkStateChanged';
+
+// ---------------------------------------------------------------------------
+// Enums
+// ---------------------------------------------------------------------------
+
+/// Discrete states for macOS-specific permissions.
+enum MacOSPermissionState {
+  /// Permission granted.
+  granted,
+
+  /// Permission denied by the user.
+  denied,
+
+  /// Permission has not yet been determined (first launch before
+  /// any prompt, or the system returned an unexpected value).
+  notDetermined,
+
+  /// No resolved state yet (cold launch before the first emission,
+  /// or non-macOS host before short-circuit). Consumers treat this
+  /// as "not yet known".
+  unknown,
+}
+
+/// Local Network permission states, extended to cover macOS 14 and
+/// earlier where Local Network Privacy does not exist.
+enum MacOSLocalNetworkState {
+  /// Permission granted or the Local Network prompt was satisfied.
+  granted,
+
+  /// Permission explicitly denied by the user (macOS 15+ only).
+  denied,
+
+  /// No prompt shown yet.
+  notDetermined,
+
+  /// Running on macOS 14 or earlier where Local Network Privacy
+  /// does not apply. Consumers treat this as "granted".
+  unsupported,
+
+  /// No resolved state yet.
+  unknown,
+}
+
+// ---------------------------------------------------------------------------
+// State parsing helpers
+// ---------------------------------------------------------------------------
+
+MacOSPermissionState _parsePermissionState(String? raw) {
+  switch (raw) {
+    case 'Granted':
+      return MacOSPermissionState.granted;
+    case 'Denied':
+      return MacOSPermissionState.denied;
+    case 'NotDetermined':
+      return MacOSPermissionState.notDetermined;
+    default:
+      return MacOSPermissionState.unknown;
+  }
+}
+
+MacOSLocalNetworkState _parseLocalNetworkState(String? raw) {
+  switch (raw) {
+    case 'Granted':
+      return MacOSLocalNetworkState.granted;
+    case 'Denied':
+      return MacOSLocalNetworkState.denied;
+    case 'NotDetermined':
+      return MacOSLocalNetworkState.notDetermined;
+    case 'Unsupported':
+      return MacOSLocalNetworkState.unsupported;
+    default:
+      return MacOSLocalNetworkState.unknown;
+  }
+}
+
+// ---------------------------------------------------------------------------
+// PTT capability level mapping
+// ---------------------------------------------------------------------------
+
+/// Maps the Input Monitoring state to the PTT capability level string
+/// consumed by [PttCapabilityBadge].
+///
+/// Trace: SDD-091 (capability badge); desktop-ptt-architecture.md
+/// (macOS Event Tap strategy).
+String _pttCapabilityLevel(MacOSPermissionState inputMonitoring) {
+  switch (inputMonitoring) {
+    case MacOSPermissionState.granted:
+      return 'L1MacOSEventTap';
+    case MacOSPermissionState.denied:
+    case MacOSPermissionState.notDetermined:
+    case MacOSPermissionState.unknown:
+      return 'L0Focused';
+  }
+}
+
+// ---------------------------------------------------------------------------
+// MacOSPermissionsService
+// ---------------------------------------------------------------------------
+
+/// Dart-side integration for macOS permission state.
+///
+/// Trace: SRS-198, SRS-297, SRS-300, SysRS-166, SDD-091.
+class MacOSPermissionsService {
+  /// Construct a service bound to [channel]. Injected for testability;
+  /// production code uses the default channel keyed on
+  /// [macOSPermissionsChannelName].
+  MacOSPermissionsService({MethodChannel? channel})
+      : _channel = channel ??
+            (_isMacOS
+                ? const MethodChannel(macOSPermissionsChannelName)
+                : null);
+
+  /// Platform-detection seam. Web counts as non-macOS.
+  static bool get _isMacOS {
+    if (kIsWeb) return false;
+    return Platform.isMacOS;
+  }
+
+  final MethodChannel? _channel;
+  bool _started = false;
+
+  // -- Input Monitoring -----------------------------------------------------
+
+  final ValueNotifier<MacOSPermissionState> _inputMonitoringState =
+      ValueNotifier<MacOSPermissionState>(
+    // Non-macOS: granted so consumers are no-ops.
+    _isMacOS
+        ? MacOSPermissionState.unknown
+        : MacOSPermissionState.granted,
+  );
+
+  /// Latest known Input Monitoring permission state.
+  ///
+  /// On macOS this drives the PTT capability level: `granted` →
+  /// `L1MacOSEventTap` (global PTT via Event Tap); anything else →
+  /// `L0Focused` (focused-only PTT).
+  ValueListenable<MacOSPermissionState> get inputMonitoringState =>
+      _inputMonitoringState;
+
+  // -- Local Network --------------------------------------------------------
+
+  final ValueNotifier<MacOSLocalNetworkState> _localNetworkState =
+      ValueNotifier<MacOSLocalNetworkState>(
+    _isMacOS
+        ? MacOSLocalNetworkState.unknown
+        : MacOSLocalNetworkState.unsupported,
+  );
+
+  /// Latest known Local Network permission state.
+  ///
+  /// On macOS 15+ (Sequoia) this reflects the Local Network Privacy
+  /// TCC permission. On macOS 14 and earlier, the value is
+  /// [MacOSLocalNetworkState.unsupported] (no prompt needed).
+  ValueListenable<MacOSLocalNetworkState> get localNetworkState =>
+      _localNetworkState;
+
+  // -- Notifications --------------------------------------------------------
+
+  final ValueNotifier<MacOSPermissionState> _notificationState =
+      ValueNotifier<MacOSPermissionState>(
+    _isMacOS
+        ? MacOSPermissionState.unknown
+        : MacOSPermissionState.granted,
+  );
+
+  /// Latest known notification authorization state.
+  ValueListenable<MacOSPermissionState> get notificationState =>
+      _notificationState;
+
+  // -- PTT capability (derived) ---------------------------------------------
+
+  final ValueNotifier<String> _pttCapabilityState =
+      ValueNotifier<String>(
+    _pttCapabilityLevel(
+      _isMacOS ? MacOSPermissionState.unknown : MacOSPermissionState.granted,
+    ),
+  );
+
+  /// Derived PTT capability level string, ready for consumption by
+  /// [PttCapabilityBadge]. Updates automatically when Input Monitoring
+  /// state changes.
+  ///
+  /// Returns `"L1MacOSEventTap"` when Input Monitoring is granted,
+  /// `"L0Focused"` otherwise.
+  ValueListenable<String> get pttCapabilityState => _pttCapabilityState;
+
+  // -- Lifecycle ------------------------------------------------------------
+
+  /// Start listening for state updates from Swift. Idempotent.
+  ///
+  /// On non-macOS this is a no-op.
+  ///
+  /// Note: this only registers the inbound handler. Call
+  /// [checkInitialStates] afterward to eagerly query the current
+  /// permission states from the native side.
+  void start() {
+    if (_started) return;
+    _started = true;
+    final ch = _channel;
+    if (ch == null) return;
+    ch.setMethodCallHandler(_handle);
+  }
+
+  /// Eagerly query the current permission states from the native
+  /// side. Call this after [start] so the PTT capability badge
+  /// shows the correct level on the first frame.
+  ///
+  /// On non-macOS this is a no-op.
+  void checkInitialStates() {
+    final ch = _channel;
+    if (ch == null) return;
+    unawaited(_checkInputMonitoring());
+    unawaited(_checkLocalNetwork());
+    unawaited(_checkNotifications());
+  }
+
+  /// Stop listening. Idempotent.
+  void stop() {
+    if (!_started) return;
+    _started = false;
+    final ch = _channel;
+    if (ch == null) return;
+    ch.setMethodCallHandler(null);
+  }
+
+  // -- Inbound handler (Swift → Dart) --------------------------------------
+
+  Future<dynamic> _handle(MethodCall call) async {
+    switch (call.method) {
+      case methodInputMonitoringStateChanged:
+        final args = call.arguments;
+        if (args is Map) {
+          final state = _parsePermissionState(args['state'] as String?);
+          _inputMonitoringState.value = state;
+          _pttCapabilityState.value = _pttCapabilityLevel(state);
+        }
+        break;
+      case methodLocalNetworkStateChanged:
+        final args = call.arguments;
+        if (args is Map) {
+          _localNetworkState.value =
+              _parseLocalNetworkState(args['state'] as String?);
+        }
+        break;
+      default:
+        break;
+    }
+    return null;
+  }
+
+  // -- Outbound: Input Monitoring -------------------------------------------
+
+  /// Check the current Input Monitoring permission state without
+  /// triggering a system prompt.
+  Future<MacOSPermissionState> _checkInputMonitoring() async {
+    final ch = _channel;
+    if (ch == null) return MacOSPermissionState.granted;
+    try {
+      final raw =
+          await ch.invokeMethod<String>(methodCheckInputMonitoring);
+      final state = _parsePermissionState(raw);
+      _inputMonitoringState.value = state;
+      _pttCapabilityState.value = _pttCapabilityLevel(state);
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'checkInputMonitoring failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _inputMonitoringState.value;
+    }
+  }
+
+  /// Request Input Monitoring permission. On macOS this calls
+  /// `CGRequestListenEventAccess()` which shows a system dialog
+  /// or opens System Settings (depending on macOS version).
+  ///
+  /// Returns the new state after the request.
+  Future<MacOSPermissionState> requestInputMonitoring() async {
+    final ch = _channel;
+    if (ch == null) return MacOSPermissionState.granted;
+    try {
+      final raw = await ch.invokeMethod<String>(
+        methodRequestInputMonitoring,
+      );
+      final state = _parsePermissionState(raw);
+      _inputMonitoringState.value = state;
+      _pttCapabilityState.value = _pttCapabilityLevel(state);
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'requestInputMonitoring failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _inputMonitoringState.value;
+    }
+  }
+
+  /// Open System Settings → Privacy & Security → Input Monitoring
+  /// so the user can manually grant the permission for the
+  /// permanently-denied case (TCC drag-based permission cannot be
+  /// programmatically granted).
+  Future<void> openInputMonitoringSettings() async {
+    final ch = _channel;
+    if (ch == null) return;
+    try {
+      await ch.invokeMethod<void>(methodOpenInputMonitoringSettings);
+    } catch (e, st) {
+      developer.log(
+        'openInputMonitoringSettings failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+    }
+  }
+
+  // -- Outbound: Local Network ----------------------------------------------
+
+  Future<MacOSLocalNetworkState> _checkLocalNetwork() async {
+    final ch = _channel;
+    if (ch == null) return MacOSLocalNetworkState.unsupported;
+    try {
+      final raw = await ch.invokeMethod<String>(methodCheckLocalNetwork);
+      final state = _parseLocalNetworkState(raw);
+      _localNetworkState.value = state;
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'checkLocalNetwork failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _localNetworkState.value;
+    }
+  }
+
+  /// Trigger the Local Network permission prompt by starting a
+  /// brief `NWBrowser` scan for `_ts3._tcp`. On macOS 15+ this
+  /// shows the system Local Network Privacy dialog. On earlier
+  /// versions, this is a no-op (returns `unsupported`).
+  Future<MacOSLocalNetworkState> triggerLocalNetworkPrompt() async {
+    final ch = _channel;
+    if (ch == null) return MacOSLocalNetworkState.unsupported;
+    try {
+      final raw = await ch.invokeMethod<String>(
+        methodTriggerLocalNetworkPrompt,
+      );
+      final state = _parseLocalNetworkState(raw);
+      _localNetworkState.value = state;
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'triggerLocalNetworkPrompt failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _localNetworkState.value;
+    }
+  }
+
+  // -- Outbound: Notifications ----------------------------------------------
+
+  Future<MacOSPermissionState> _checkNotifications() async {
+    final ch = _channel;
+    if (ch == null) return MacOSPermissionState.granted;
+    try {
+      final raw =
+          await ch.invokeMethod<String>(methodCheckNotifications);
+      final state = _parsePermissionState(raw);
+      _notificationState.value = state;
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'checkNotifications failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _notificationState.value;
+    }
+  }
+
+  /// Request notification authorization via `UNUserNotificationCenter`.
+  /// Returns the new state after the system dialog resolves.
+  Future<MacOSPermissionState> requestNotifications() async {
+    final ch = _channel;
+    if (ch == null) return MacOSPermissionState.granted;
+    try {
+      final raw = await ch.invokeMethod<String>(
+        methodRequestNotifications,
+      );
+      final state = _parsePermissionState(raw);
+      _notificationState.value = state;
+      return state;
+    } catch (e, st) {
+      developer.log(
+        'requestNotifications failed',
+        name: 'MacOSPermissionsService',
+        error: e,
+        stackTrace: st,
+      );
+      return _notificationState.value;
+    }
+  }
+
+  // -- Cleanup --------------------------------------------------------------
+
+  /// Release state notifiers. Test helper; production keeps the
+  /// service alive for the lifetime of the app.
+  @visibleForTesting
+  void dispose() {
+    stop();
+    _inputMonitoringState.dispose();
+    _localNetworkState.dispose();
+    _notificationState.dispose();
+    _pttCapabilityState.dispose();
+  }
+}
@@ -40,5 +40,9 @@
 	<string>Chanora uses Input Monitoring so push-to-talk keys work even when other apps are focused. Chanora never records what you type — only the key you bound for talking.</string>
 	<key>NSLocalNetworkUsageDescription</key>
 	<string>Chanora needs local network access to connect to TeamSpeak-compatible voice servers.</string>
+	<key>NSBonjourServices</key>
+	<array>
+		<string>_ts3._tcp</string>
+	</array>
 </dict>
 </plist>
@@ -1,5 +1,292 @@
 import Cocoa
 import FlutterMacOS
+import CoreGraphics
+import Network
+import UserNotifications
+
+// ---------------------------------------------------------------------------
+// MacOSPermissionsHandler
+//
+// Native-side MethodChannel handler for macOS-specific permissions
+// that the Flutter `permission_handler` plugin does not cover:
+//
+//   • Input Monitoring  (CGPreflightListenEventAccess /
+//                        CGRequestListenEventAccess) for global PTT.
+//   • Local Network     (NWBrowser trigger for _ts3._tcp) so macOS 15+
+//                        shows the Local Network Privacy prompt.
+//   • Notifications     (UNUserNotificationCenter authorization).
+//
+// Channel name: `app.chanora/macos_permissions`
+//
+// Trace: SRS-198, SRS-297, SRS-300, SysRS-166, SDD-091.
+// ---------------------------------------------------------------------------
+
+/// Polling interval for Input Monitoring state changes.
+/// TCC does not emit a callback when the user toggles Input Monitoring
+/// in System Settings, so we poll at a reasonable cadence.
+private let kInputMonitoringPollInterval: TimeInterval = 2.0
+
+class MacOSPermissionsHandler: NSObject, FlutterPlugin {
+  private var channel: FlutterMethodChannel?
+  private var inputMonitoringTimer: Timer?
+  private var lastInputMonitoringState: String = "Unknown"
+
+  // -- FlutterPlugin -------------------------------------------------------
+
+  static func register(with registrar: FlutterPluginRegistrar) {
+    let channel = FlutterMethodChannel(
+      name: "app.chanora/macos_permissions",
+      binaryMessenger: registrar.messenger
+    )
+    let instance = MacOSPermissionsHandler()
+    instance.channel = channel
+    registrar.addMethodCallDelegate(instance, channel: channel)
+  }
+
+  func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+    switch call.method {
+    // -- Input Monitoring ---------------------------------------------------
+    case "checkInputMonitoring":
+      result(inputMonitoringStateString())
+      startInputMonitoringPolling()
+
+    case "requestInputMonitoring":
+      requestInputMonitoring(result: result)
+
+    case "openInputMonitoringSettings":
+      openInputMonitoringSettings(result: result)
+
+    // -- Local Network ------------------------------------------------------
+    case "checkLocalNetwork":
+      checkLocalNetwork(result: result)
+
+    case "triggerLocalNetworkPrompt":
+      triggerLocalNetworkPrompt(result: result)
+
+    // -- Notifications ------------------------------------------------------
+    case "checkNotifications":
+      checkNotifications(result: result)
+
+    case "requestNotifications":
+      requestNotifications(result: result)
+
+    default:
+      result(FlutterMethodNotImplemented)
+    }
+  }
+
+  // =========================================================================
+  // Input Monitoring
+  // =========================================================================
+
+  /// Returns the current Input Monitoring state as a string
+  /// consumable by the Dart side: "Granted", "Denied", "NotDetermined".
+  private func inputMonitoringStateString() -> String {
+    // CGPreflightListenEventAccess returns true when access is already
+    // granted. On macOS 10.15+ it returns false when denied or not yet
+    // determined — we cannot distinguish those two without attempting
+    // CGRequestListenEventAccess, so we conservatively report
+    // "NotDetermined" when preflight returns false. The Dart side
+    // treats both "Denied" and "NotDetermined" as L0Focused.
+    if CGPreflightListenEventAccess() {
+      return "Granted"
+    }
+    return "NotDetermined"
+  }
+
+  /// Request Input Monitoring permission via
+  /// `CGRequestListenEventAccess()`. On macOS 13+ this opens
+  /// System Settings → Privacy & Security → Input Monitoring.
+  private func requestInputMonitoring(result: @escaping FlutterResult) {
+    // CGRequestListenEventAccess shows the system prompt.
+    // It returns true if access was already granted or becomes
+    // granted synchronously (rare). Most of the time it returns
+    // false and the user must toggle the switch manually.
+    let granted = CGRequestListenEventAccess()
+    let state = granted ? "Granted" : "NotDetermined"
+    lastInputMonitoringState = state
+    result(state)
+
+    // Start polling so we detect when the user grants in Settings.
+    startInputMonitoringPolling()
+  }
+
+  /// Open System Settings → Privacy & Security → Input Monitoring
+  /// so the user can manually enable the app.
+  private func openInputMonitoringSettings(result: @escaping FlutterResult) {
+    if let url = URL(
+      string: "x-apple.systempreferences:com.apple.preference.security?Privacy_ListenEvent"
+    ) {
+      NSWorkspace.shared.open(url)
+    }
+    result(nil)
+  }
+
+  /// Start a periodic timer that checks Input Monitoring state and
+  /// notifies the Dart side when it changes.
+  private func startInputMonitoringPolling() {
+    // Don't start a second timer if one is already running.
+    guard inputMonitoringTimer == nil else { return }
+    lastInputMonitoringState = inputMonitoringStateString()
+
+    inputMonitoringTimer = Timer.scheduledTimer(
+      withTimeInterval: kInputMonitoringPollInterval,
+      repeats: true
+    ) { [weak self] _ in
+      self?.pollInputMonitoring()
+    }
+  }
+
+  private func pollInputMonitoring() {
+    let current = inputMonitoringStateString()
+    guard current != lastInputMonitoringState else { return }
+    lastInputMonitoringState = current
+
+    // Notify the Dart side via the inbound method.
+    channel?.invokeMethod("inputMonitoringStateChanged", arguments: [
+      "state": current,
+    ])
+  }
+
+  // =========================================================================
+  // Local Network
+  // =========================================================================
+
+  /// Check whether Local Network access is available.
+  /// On macOS 14 and earlier, Local Network Privacy does not exist,
+  /// so we report "Unsupported". On macOS 15+, we attempt a brief
+  /// NWBrowser scan and report based on the result.
+  private func checkLocalNetwork(result: @escaping FlutterResult) {
+    if #available(macOS 15.0, *) {
+      // We cannot synchronously determine the Local Network state
+      // without actually using the network. Report "NotDetermined"
+      // and let triggerLocalNetworkPrompt resolve the actual state.
+      result("NotDetermined")
+    } else {
+      result("Unsupported")
+    }
+  }
+
+  /// Trigger the Local Network Privacy prompt by starting a brief
+  /// NWBrowser for `_ts3._tcp`. On macOS 15+, this causes the system
+  /// to show the Local Network permission dialog if not already
+  /// determined.
+  ///
+  /// The browser is started and stopped after a short scan window.
+  /// State changes are reported back to Dart via
+  /// `localNetworkStateChanged`.
+  @available(macOS 15.0, *)
+  private func triggerLocalNetworkPromptImpl(result: @escaping FlutterResult) {
+    let bonjourType = "_ts3._tcp"
+    let browserDescriptor = NWBrowser.Descriptor.bonjourWithTXTRecord(
+      type: bonjourType, domain: nil)
+    let browser = NWBrowser(for: browserDescriptor, using: NWParameters.tcp)
+
+    var resolved = false
+
+    browser.stateUpdateHandler = { [weak self] (browserState: NWBrowser.State) in
+      switch browserState {
+      case .ready:
+        // Browser started successfully — local network is accessible.
+        if !resolved {
+          resolved = true
+          result("Granted")
+          self?.channel?.invokeMethod("localNetworkStateChanged", arguments: [
+            "state": "Granted",
+          ])
+        }
+        browser.cancel()
+      case .failed(let error):
+        if !resolved {
+          resolved = true
+          let code = error.errorCode
+          // POSIX permission-denied or network-down signals that
+          // the user denied the Local Network prompt.
+          if code == ENETDOWN || code == EACCES || code == EPERM {
+            result("Denied")
+            self?.channel?.invokeMethod("localNetworkStateChanged", arguments: [
+              "state": "Denied",
+            ])
+          } else {
+            // Network unreachable or other transient error —
+            // don't assume denied.
+            result("NotDetermined")
+          }
+        }
+        browser.cancel()
+      case .waiting:
+        // The browser is waiting for network — this is normal and
+        // may mean the permission dialog is showing. Don't resolve
+        // yet; wait for .ready or .failed or the timeout.
+        break
+      case .setup, .cancelled:
+        break
+      @unknown default:
+        break
+      }
+    }
+
+    browser.start(queue: DispatchQueue.main)
+
+    // Timeout: if the browser doesn't resolve within 10 seconds,
+    // report NotDetermined so the Dart side doesn't hang forever.
+    DispatchQueue.main.asyncAfter(deadline: .now() + 10.0) {
+      if !resolved {
+        resolved = true
+        result("NotDetermined")
+        browser.cancel()
+      }
+    }
+  }
+
+  private func triggerLocalNetworkPrompt(result: @escaping FlutterResult) {
+    if #available(macOS 15.0, *) {
+      triggerLocalNetworkPromptImpl(result: result)
+    } else {
+      result("Unsupported")
+    }
+  }
+
+  // =========================================================================
+  // Notifications
+  // =========================================================================
+
+  private func checkNotifications(result: @escaping FlutterResult) {
+    UNUserNotificationCenter.current().getNotificationSettings { settings in
+      switch settings.authorizationStatus {
+      case .authorized, .provisional:
+        result("Granted")
+      case .denied:
+        result("Denied")
+      case .notDetermined:
+        result("NotDetermined")
+      @unknown default:
+        result("NotDetermined")
+      }
+    }
+  }
+
+  private func requestNotifications(result: @escaping FlutterResult) {
+    UNUserNotificationCenter.current().requestAuthorization(options: [
+      .alert, .sound, .badge,
+    ]) { granted, _ in
+      let state = granted ? "Granted" : "Denied"
+      result(state)
+    }
+  }
+
+  // =========================================================================
+  // Cleanup
+  // =========================================================================
+
+  deinit {
+    inputMonitoringTimer?.invalidate()
+  }
+}
+
+// ---------------------------------------------------------------------------
+// MainFlutterWindow
+// ---------------------------------------------------------------------------

 class MainFlutterWindow: NSWindow {
  override func awakeFromNib() {
@@ -15,6 +302,9 @@ class MainFlutterWindow: NSWindow {

    RegisterGeneratedPlugins(registry: flutterViewController)

+    // Register the macOS permissions MethodChannel handler.
+    MacOSPermissionsHandler.register(with: flutterViewController.registrar(forPlugin: "MacOSPermissionsHandler"))
+
    super.awakeFromNib()
  }
 }
@@ -0,0 +1,505 @@
+// SWE.4 unit tests for MacOSPermissionsService — the Dart-side
+// integration layer for the Swift `MacOSPermissionsHandler`
+// (SRS-198, SRS-297, SRS-300, SysRS-166, SDD-091).
+//
+// Requirement trace:
+//   Verification-plan row: SWE4-UV-XXX.
+//   SRS-198 (Push-to-talk system permission acquisition).
+//   SRS-297 / SRS-300 (Input Monitoring for global PTT on macOS).
+//   SysRS-166 (Desktop notifications).
+//   SDD-091 (PTT capability badge — live capability level).
+//
+// Strategy: Following the pattern in
+// `android_permissions_service_test.dart`, use
+// `TestDefaultBinaryMessengerBinding` to (a) capture outbound
+// method invocations and (b) inject inbound state-change calls as
+// if Swift had emitted them.
+//
+// Platform note: these tests run on macOS. The static `_isMacOS`
+// check inside the service evaluates to true at field-initialization
+// time, so the ValueNotifiers seed to `unknown` (not `granted`).
+// This is intentional — on macOS the service must query the native
+// side before it knows the real state. Tests that inject a channel
+// observe `unknown` as the initial value and drive transitions from
+// there. The channel-null short-circuit test documents that when
+// channel is null, outbound calls are suppressed and each method
+// returns its safe default.
+
+import 'dart:io' show Platform;
+
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:chanora_flutter/services/macos_permissions_service.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  /// Whether the test host is actually macOS — the field initializers
+  /// inside `MacOSPermissionsService` use `Platform.isMacOS` (not
+  /// injectable), so the initial state values depend on this.
+  final bool hostIsMacOS = !kIsWeb && Platform.isMacOS;
+
+  late MethodChannel channel;
+  late List<MethodCall> outgoingCalls;
+
+  /// Intercept outbound calls AFTER the service's handler is installed.
+  /// We store a reference so outbound invokeMethod calls can be
+  /// captured while inbound handlePlatformMessage calls are routed
+  /// to the service's handler.
+  Future<Object?> Function(MethodCall call)? outgoingResponder;
+
+  Future<void> sendInputMonitoringStateChanged({
+    required String state,
+  }) async {
+    const codec = StandardMethodCodec();
+    final encoded = codec.encodeMethodCall(
+      MethodCall(methodInputMonitoringStateChanged, <String, dynamic>{
+        'state': state,
+      }),
+    );
+    await TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .handlePlatformMessage(channel.name, encoded, (_) {});
+  }
+
+  Future<void> sendLocalNetworkStateChanged({
+    required String state,
+  }) async {
+    const codec = StandardMethodCodec();
+    final encoded = codec.encodeMethodCall(
+      MethodCall(methodLocalNetworkStateChanged, <String, dynamic>{
+        'state': state,
+      }),
+    );
+    await TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .handlePlatformMessage(channel.name, encoded, (_) {});
+  }
+
+  setUp(() {
+    channel = const MethodChannel(macOSPermissionsChannelName);
+    outgoingCalls = <MethodCall>[];
+    outgoingResponder = null;
+
+    // The mock handler captures outbound calls AND delegates inbound
+    // platform messages to the service handler when set.
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, (call) async {
+      outgoingCalls.add(call);
+      final r = outgoingResponder;
+      if (r != null) return r(call);
+      return null;
+    });
+  });
+
+  tearDown(() {
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, null);
+  });
+
+  // ===========================================================================
+  // Initial state
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: a fresh service exposes a deterministic initial '
+    'inputMonitoringState that matches the host platform',
+    () {
+      final svc = MacOSPermissionsService(channel: channel);
+      if (hostIsMacOS) {
+        // On macOS the service hasn't queried the native side yet.
+        expect(svc.inputMonitoringState.value, MacOSPermissionState.unknown);
+        expect(svc.pttCapabilityState.value, 'L0Focused');
+      } else {
+        // On non-macOS the static check short-circuits to granted.
+        expect(svc.inputMonitoringState.value, MacOSPermissionState.granted);
+        expect(svc.pttCapabilityState.value, 'L1MacOSEventTap');
+      }
+      svc.dispose();
+    },
+  );
+
+  // ===========================================================================
+  // Input Monitoring — inbound state changes
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: inbound inputMonitoringStateChanged with '
+    'state=Granted transitions inputMonitoringState and PTT capability',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      // Drive away from the initial value first.
+      await sendInputMonitoringStateChanged(state: 'Denied');
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.denied);
+      expect(svc.pttCapabilityState.value, 'L0Focused');
+
+      var notified = 0;
+      void listener() => notified++;
+      svc.inputMonitoringState.addListener(listener);
+
+      await sendInputMonitoringStateChanged(state: 'Granted');
+
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.granted);
+      expect(svc.pttCapabilityState.value, 'L1MacOSEventTap');
+      expect(notified, greaterThanOrEqualTo(1));
+
+      svc.inputMonitoringState.removeListener(listener);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-297: inbound inputMonitoringStateChanged with '
+    'state=Denied transitions to denied and L0Focused',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendInputMonitoringStateChanged(state: 'Denied');
+
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.denied);
+      expect(svc.pttCapabilityState.value, 'L0Focused');
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-297: inbound inputMonitoringStateChanged with '
+    'state=NotDetermined transitions to notDetermined and L0Focused',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendInputMonitoringStateChanged(state: 'NotDetermined');
+
+      expect(
+        svc.inputMonitoringState.value,
+        MacOSPermissionState.notDetermined,
+      );
+      expect(svc.pttCapabilityState.value, 'L0Focused');
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-297: inbound inputMonitoringStateChanged with '
+    'malformed state parses to unknown and L0Focused',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      // Start from a known baseline.
+      await sendInputMonitoringStateChanged(state: 'Granted');
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.granted);
+
+      await sendInputMonitoringStateChanged(state: 'Bogus');
+
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.unknown);
+      expect(svc.pttCapabilityState.value, 'L0Focused');
+      svc.dispose();
+    },
+  );
+
+  // ===========================================================================
+  // Local Network — inbound state changes
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-300: inbound localNetworkStateChanged with '
+    'state=Granted transitions localNetworkState',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendLocalNetworkStateChanged(state: 'Granted');
+
+      expect(svc.localNetworkState.value, MacOSLocalNetworkState.granted);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-300: inbound localNetworkStateChanged with '
+    'state=Denied transitions localNetworkState',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendLocalNetworkStateChanged(state: 'Denied');
+
+      expect(svc.localNetworkState.value, MacOSLocalNetworkState.denied);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-300: inbound localNetworkStateChanged with '
+    'state=Unsupported transitions localNetworkState',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendLocalNetworkStateChanged(state: 'Unsupported');
+
+      expect(
+        svc.localNetworkState.value,
+        MacOSLocalNetworkState.unsupported,
+      );
+      svc.dispose();
+    },
+  );
+
+  // ===========================================================================
+  // Outbound method calls
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: requestInputMonitoring() emits outbound '
+    'requestInputMonitoring MethodCall; returns the platform response',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      outgoingResponder = (call) async {
+        if (call.method == methodRequestInputMonitoring) {
+          return 'Granted';
+        }
+        return null;
+      };
+
+      final result = await svc.requestInputMonitoring();
+
+      expect(
+        outgoingCalls.where((c) => c.method == methodRequestInputMonitoring),
+        hasLength(1),
+        reason: 'requestInputMonitoring must be called',
+      );
+      expect(result, MacOSPermissionState.granted);
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.granted);
+      expect(svc.pttCapabilityState.value, 'L1MacOSEventTap');
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-300: triggerLocalNetworkPrompt() emits outbound '
+    'triggerLocalNetworkPrompt MethodCall; returns the platform response',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      outgoingResponder = (call) async {
+        if (call.method == methodTriggerLocalNetworkPrompt) {
+          return 'Granted';
+        }
+        return null;
+      };
+
+      final result = await svc.triggerLocalNetworkPrompt();
+
+      expect(
+        outgoingCalls
+            .where((c) => c.method == methodTriggerLocalNetworkPrompt),
+        hasLength(1),
+        reason: 'triggerLocalNetworkPrompt must be called',
+      );
+      expect(result, MacOSLocalNetworkState.granted);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SysRS-166: requestNotifications() emits outbound '
+    'requestNotifications MethodCall; returns the platform response',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      outgoingResponder = (call) async {
+        if (call.method == methodRequestNotifications) {
+          return 'Granted';
+        }
+        return null;
+      };
+
+      final result = await svc.requestNotifications();
+
+      expect(
+        outgoingCalls.where((c) => c.method == methodRequestNotifications),
+        hasLength(1),
+        reason: 'requestNotifications must be called',
+      );
+      expect(result, MacOSPermissionState.granted);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-297: openInputMonitoringSettings() emits outbound '
+    'openInputMonitoringSettings MethodCall',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await svc.openInputMonitoringSettings();
+
+      final calls = outgoingCalls
+          .where((c) => c.method == methodOpenInputMonitoringSettings)
+          .toList();
+      expect(calls, hasLength(1));
+      svc.dispose();
+    },
+  );
+
+  // ===========================================================================
+  // Lifecycle
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: start() is idempotent — calling it twice '
+    'does not double-register the handler',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)
+        ..start()
+        ..start();
+
+      var notified = 0;
+      void listener() => notified++;
+      svc.inputMonitoringState.addListener(listener);
+
+      await sendInputMonitoringStateChanged(state: 'Denied');
+
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.denied);
+      expect(notified, 1);
+
+      svc.inputMonitoringState.removeListener(listener);
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-297: stop() removes the handler — subsequent '
+    'inbound messages have no effect on state',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      await sendInputMonitoringStateChanged(state: 'Denied');
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.denied);
+
+      svc.stop();
+
+      await sendInputMonitoringStateChanged(state: 'Granted');
+
+      expect(
+        svc.inputMonitoringState.value,
+        MacOSPermissionState.denied,
+        reason: 'state must be frozen after stop()',
+      );
+    },
+  );
+
+  // ===========================================================================
+  // Non-macOS short-circuit (channel is null)
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: null-channel short-circuit — on non-macOS hosts '
+    'the constructor seeds to safe defaults; on macOS hosts, passing '
+    'channel:null still creates a real channel because _isMacOS is true',
+    () async {
+      if (!hostIsMacOS) {
+        // On non-macOS: the constructor's `_isMacOS` branch is false,
+        // so `_channel` stays null. All methods return safe defaults
+        // without touching any channel.
+        final svc = MacOSPermissionsService(channel: null);
+        expect(
+          svc.inputMonitoringState.value,
+          MacOSPermissionState.granted,
+        );
+        expect(
+          svc.localNetworkState.value,
+          MacOSLocalNetworkState.unsupported,
+        );
+        expect(
+          svc.notificationState.value,
+          MacOSPermissionState.granted,
+        );
+
+        final priorOutgoing = outgoingCalls.length;
+        await svc.requestInputMonitoring();
+        await svc.triggerLocalNetworkPrompt();
+        await svc.requestNotifications();
+        await svc.openInputMonitoringSettings();
+
+        expect(
+          outgoingCalls.length,
+          priorOutgoing,
+          reason: 'no outbound calls when platform is non-macOS',
+        );
+
+        svc.start();
+        svc.stop();
+        svc.dispose();
+      } else {
+        // On macOS: even with channel: null, the constructor creates
+        // a MethodChannel because _isMacOS is true. This is the
+        // correct production behaviour — on macOS the service always
+        // has a channel. The short-circuit path is unreachable on
+        // macOS by design.
+        final svc = MacOSPermissionsService(channel: null);
+        // The service has a non-null _channel, so methods will attempt
+        // to invoke the channel (which has no native handler in tests).
+        // Verify the service doesn't throw and returns a value.
+        final result = await svc.requestInputMonitoring();
+        expect(result, isNotNull);
+        svc.dispose();
+      }
+    },
+  );
+
+  // ===========================================================================
+  // Channel error handling
+  // ===========================================================================
+
+  test(
+    'SWE4-UV / SRS-297: requestInputMonitoring() returns cached state '
+    'when the channel throws',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      // Seed a known state via inbound.
+      await sendInputMonitoringStateChanged(state: 'Denied');
+      expect(svc.inputMonitoringState.value, MacOSPermissionState.denied);
+
+      // Make the platform stub throw.
+      outgoingResponder = (call) async {
+        if (call.method == methodRequestInputMonitoring) {
+          throw PlatformException(code: 'unavailable');
+        }
+        return null;
+      };
+
+      final result = await svc.requestInputMonitoring();
+
+      expect(
+        result,
+        MacOSPermissionState.denied,
+        reason:
+            'on channel failure requestInputMonitoring must return cached state',
+      );
+      svc.dispose();
+    },
+  );
+
+  test(
+    'SWE4-UV / SRS-300: triggerLocalNetworkPrompt() returns cached state '
+    'when the channel throws',
+    () async {
+      final svc = MacOSPermissionsService(channel: channel)..start();
+
+      outgoingResponder = (call) async {
+        if (call.method == methodTriggerLocalNetworkPrompt) {
+          throw PlatformException(code: 'unavailable');
+        }
+        return null;
+      };
+
+      final result = await svc.triggerLocalNetworkPrompt();
+
+      // Returns the cached state without crashing.
+      expect(result, isNotNull);
+      svc.dispose();
+    },
+  );
+}