Migrate fuchsia_device to null safety (#95438)

packages/flutter_tools/lib/src/fuchsia/fuchsia_build.dart

@@ -2,10 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
-import 'package:meta/meta.dart';
-
 import '../artifacts.dart';
 import '../asset.dart';
 import '../base/common.dart';
@@ -45,12 +41,13 @@ Future<void> _validateCmxFile(FuchsiaProject fuchsiaProject) async {
 // 3. Using these manifests, use the Fuchsia SDK 'pm' tool to create the
 //    Fuchsia package.
 Future<void> buildFuchsia({
-  @required FuchsiaProject fuchsiaProject,
-  @required TargetPlatform targetPlatform,
-  @required String target, // E.g., lib/main.dart
+  required FuchsiaProject fuchsiaProject,
+  required TargetPlatform targetPlatform,
+  String? target, // E.g., lib/main.dart
   BuildInfo buildInfo = BuildInfo.debug,
   String runnerPackageSource = FuchsiaPackageServer.toolHost,
 }) async {
+  final String targetPath = target ??= 'lib/main.dart';
   await _validateCmxFile(fuchsiaProject);
   final Directory outDir = globals.fs.directory(getFuchsiaBuildDirectory());
   if (!outDir.existsSync()) {
@@ -58,18 +55,18 @@ Future<void> buildFuchsia({
   }
 
   await _timedBuildStep('fuchsia-kernel-compile',
-    () => fuchsiaSdk.fuchsiaKernelCompiler.build(
-      fuchsiaProject: fuchsiaProject, target: target, buildInfo: buildInfo));
+    () => fuchsiaSdk!.fuchsiaKernelCompiler.build(
+      fuchsiaProject: fuchsiaProject, target: targetPath, buildInfo: buildInfo));
 
   if (buildInfo.usesAot) {
     await _timedBuildStep('fuchsia-gen-snapshot',
-      () => _genSnapshot(fuchsiaProject, target, buildInfo, targetPlatform));
+      () => _genSnapshot(fuchsiaProject, targetPath, buildInfo, targetPlatform));
   }
 
   await _timedBuildStep('fuchsia-build-assets',
-    () => _buildAssets(fuchsiaProject, target, buildInfo));
+    () => _buildAssets(fuchsiaProject, targetPath, buildInfo));
   await _timedBuildStep('fuchsia-build-package',
-    () => _buildPackage(fuchsiaProject, target, buildInfo, runnerPackageSource));
+    () => _buildPackage(fuchsiaProject, targetPath, buildInfo, runnerPackageSource));
 }
 
 Future<void> _genSnapshot(
@@ -84,7 +81,7 @@ Future<void> _genSnapshot(
 
   final String elf = globals.fs.path.join(outDir, 'elf.aotsnapshot');
 
-  final String genSnapshot = globals.artifacts.getArtifactPath(
+  final String genSnapshot = globals.artifacts!.getArtifactPath(
     Artifact.genSnapshot,
     platform: targetPlatform,
     mode: buildInfo.mode,
@@ -118,7 +115,7 @@ Future<void> _buildAssets(
   BuildInfo buildInfo,
 ) async {
   final String assetDir = getAssetBuildDirectory();
-  final AssetBundle assets = await buildAssets(
+  final AssetBundle? assets = await buildAssets(
     manifestPath: fuchsiaProject.project.pubspecFile.path,
     packagesPath: fuchsiaProject.project.packagesFile.path,
     assetDirPath: assetDir,
@@ -148,7 +145,7 @@ Future<void> _buildAssets(
 }
 
 void _rewriteCmx(BuildMode mode, String runnerPackageSource, File src, File dst) {
-  final Map<String, dynamic> cmx = castStringKeyedMap(json.decode(src.readAsStringSync()));
+  final Map<String, Object?> cmx = castStringKeyedMap(json.decode(src.readAsStringSync())) ?? <String, Object?>{};
   // If the app author has already specified the runner in the cmx file, then
   // do not override it with something else.
   if (cmx.containsKey('runner')) {
@@ -171,7 +168,6 @@ void _rewriteCmx(BuildMode mode, String runnerPackageSource, File src, File dst)
       break;
     default:
       throwToolExit('Fuchsia does not support build mode "$mode"');
-      break;
   }
   cmx['runner'] = 'fuchsia-pkg://$runnerPackageSource/$runner#meta/$runner.cmx';
   dst.writeAsStringSync(json.encode(cmx));
@@ -218,7 +214,10 @@ Future<void> _buildPackage(
   manifestFile.writeAsStringSync('meta/package=$pkgDir/meta/package\n',
       mode: FileMode.append);
 
-  final FuchsiaPM fuchsiaPM = fuchsiaSdk.fuchsiaPM;
+  final FuchsiaPM? fuchsiaPM = fuchsiaSdk?.fuchsiaPM;
+  if (fuchsiaPM == null) {
+    return;
+  }
   if (!await fuchsiaPM.init(pkgDir, appName)) {
     return;
   }

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

@@ -2,11 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'dart:async';
 
 import 'package:meta/meta.dart';
+import 'package:vm_service/vm_service.dart' as vm_service;
 
 import '../application_package.dart';
 import '../artifacts.dart';
@@ -36,19 +35,13 @@ import 'session_control.dart';
 import 'tiles_ctl.dart';
 
 /// The [FuchsiaDeviceTools] instance.
-FuchsiaDeviceTools get fuchsiaDeviceTools => context.get<FuchsiaDeviceTools>();
+FuchsiaDeviceTools get fuchsiaDeviceTools => context.get<FuchsiaDeviceTools>()!;
 
 /// Fuchsia device-side tools.
 class FuchsiaDeviceTools {
-  FuchsiaPkgctl _pkgctl;
-  FuchsiaPkgctl get pkgctl => _pkgctl ??= FuchsiaPkgctl();
-
-  FuchsiaTilesCtl _tilesCtl;
-  FuchsiaTilesCtl get tilesCtl => _tilesCtl ??= FuchsiaTilesCtl();
-
-  FuchsiaSessionControl _sessionControl;
-  FuchsiaSessionControl get sessionControl =>
-      _sessionControl ??= FuchsiaSessionControl();
+  late final FuchsiaPkgctl pkgctl = FuchsiaPkgctl();
+  late final FuchsiaTilesCtl tilesCtl = FuchsiaTilesCtl();
+  late final FuchsiaSessionControl sessionControl = FuchsiaSessionControl();
 }
 
 final String _ipv4Loopback = InternetAddress.loopbackIPv4.address;
@@ -81,21 +74,21 @@ class _FuchsiaLogReader extends DeviceLogReader {
   static final RegExp _flutterLogOutput = RegExp(r'INFO: \S+\(flutter\): ');
 
   final FuchsiaDevice _device;
-  final ApplicationPackage _app;
+  final ApplicationPackage? _app;
   final SystemClock _systemClock;
 
   @override
   String get name => _device.name;
 
-  Stream<String> _logLines;
+  Stream<String>? _logLines;
   @override
   Stream<String> get logLines {
-    final Stream<String> logStream = fuchsiaSdk.syslogs(_device.id);
+    final Stream<String>? logStream = fuchsiaSdk?.syslogs(_device.id);
     _logLines ??= _processLogs(logStream);
-    return _logLines;
+    return _logLines ?? const Stream<String>.empty();
   }
 
-  Stream<String> _processLogs(Stream<String> lines) {
+  Stream<String>? _processLogs(Stream<String>? lines) {
     if (lines == null) {
       return null;
     }
@@ -104,9 +97,10 @@ class _FuchsiaLogReader extends DeviceLogReader {
     final DateTime startTime = _systemClock.now();
     // Determine if line comes from flutter, and optionally whether it matches
     // the correct fuchsia module.
-    final RegExp matchRegExp = _app == null
+    final ApplicationPackage? app = _app;
+    final RegExp matchRegExp = app == null
         ? _flutterLogOutput
-        : RegExp('INFO: ${_app.name}(\\.cmx)?\\(flutter\\): ');
+        : RegExp('INFO: ${app.name}(\\.cmx)?\\(flutter\\): ');
     return Stream<String>.eventTransformed(
       lines,
       (EventSink<String> output) => _FuchsiaLogSink(output, matchRegExp, startTime),
@@ -136,7 +130,7 @@ class _FuchsiaLogSink implements EventSink<String> {
     if (!_matchRegExp.hasMatch(line)) {
       return;
     }
-    final String rawDate = _utcDateOutput.firstMatch(line)?.group(0);
+    final String? rawDate = _utcDateOutput.firstMatch(line)?.group(0);
     if (rawDate == null) {
       return;
     }
@@ -149,7 +143,7 @@ class _FuchsiaLogSink implements EventSink<String> {
   }
 
   @override
-  void addError(Object error, [StackTrace stackTrace]) {
+  void addError(Object error, [StackTrace? stackTrace]) {
     _outputSink.addError(error, stackTrace);
   }
 
@@ -162,10 +156,10 @@ class _FuchsiaLogSink implements EventSink<String> {
 /// Device discovery for Fuchsia devices.
 class FuchsiaDevices extends PollingDeviceDiscovery {
   FuchsiaDevices({
-    @required Platform platform,
-    @required FuchsiaWorkflow fuchsiaWorkflow,
-    @required FuchsiaSdk fuchsiaSdk,
-    @required Logger logger,
+    required Platform platform,
+    required FuchsiaWorkflow fuchsiaWorkflow,
+    required FuchsiaSdk fuchsiaSdk,
+    required Logger logger,
   }) : _platform = platform,
        _fuchsiaWorkflow = fuchsiaWorkflow,
        _fuchsiaSdk = fuchsiaSdk,
@@ -184,12 +178,12 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
   bool get canListAnything => _fuchsiaWorkflow.canListDevices;
 
   @override
-  Future<List<Device>> pollingGetDevices({ Duration timeout }) async {
+  Future<List<Device>> pollingGetDevices({ Duration? timeout }) async {
     if (!_fuchsiaWorkflow.canListDevices) {
       return <Device>[];
     }
     // TODO(omerlevran): Remove once soft transition is complete fxb/67602.
-    final List<String> text = (await _fuchsiaSdk.listDevices(
+    final List<String>? text = (await _fuchsiaSdk.listDevices(
       timeout: timeout,
     ))?.split('\n');
     if (text == null || text.isEmpty) {
@@ -197,7 +191,7 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
     }
     final List<FuchsiaDevice> devices = <FuchsiaDevice>[];
     for (final String line in text) {
-      final FuchsiaDevice device = await _parseDevice(line);
+      final FuchsiaDevice? device = await _parseDevice(line);
       if (device == null) {
         continue;
       }
@@ -209,7 +203,7 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
   @override
   Future<List<String>> getDiagnostics() async => const <String>[];
 
-  Future<FuchsiaDevice> _parseDevice(String text) async {
+  Future<FuchsiaDevice?> _parseDevice(String text) async {
     final String line = text.trim();
     // ['ip', 'device name']
     final List<String> words = line.split(' ');
@@ -219,7 +213,7 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
     final String name = words[1];
 
      // TODO(omerlevran): Add support for resolve on the FuchsiaSdk Object.
-    final String resolvedHost = await _fuchsiaSdk.fuchsiaFfx.resolve(name);
+    final String? resolvedHost = await _fuchsiaSdk.fuchsiaFfx.resolve(name);
     if (resolvedHost == null) {
       _logger.printError('Failed to resolve host for Fuchsia device `$name`');
       return null;
@@ -233,7 +227,7 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
 
 
 class FuchsiaDevice extends Device {
-  FuchsiaDevice(String id, {this.name}) : super(
+  FuchsiaDevice(String id, {required this.name}) : super(
       id,
       platformType: PlatformType.fuchsia,
       category: null,
@@ -256,14 +250,12 @@ class FuchsiaDevice extends Device {
   Future<bool> get isLocalEmulator async => false;
 
   @override
-  Future<String> get emulatorId async => null;
+  Future<String?> get emulatorId async => null;
 
   @override
   bool get supportsStartPaused => false;
 
-  bool _isSession;
-
-  Future<bool> get isSession async => _isSession ??= await _initIsSession();
+  late final Future<bool> isSession = _initIsSession();
 
   /// Determine if the Fuchsia device is running a session based build.
   ///
@@ -280,7 +272,7 @@ class FuchsiaDevice extends Device {
   @override
   Future<bool> isAppInstalled(
     ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   }) async => false;
 
   @override
@@ -289,13 +281,13 @@ class FuchsiaDevice extends Device {
   @override
   Future<bool> installApp(
     ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   }) => Future<bool>.value(false);
 
   @override
   Future<bool> uninstallApp(
     ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   }) async => false;
 
   @override
@@ -307,13 +299,13 @@ class FuchsiaDevice extends Device {
   @override
   Future<LaunchResult> startApp(
     covariant FuchsiaApp package, {
-    String mainPath,
-    String route,
-    DebuggingOptions debuggingOptions,
-    Map<String, dynamic> platformArgs,
+    String? mainPath,
+    String? route,
+    required DebuggingOptions debuggingOptions,
+    Map<String, Object?> platformArgs = const <String, Object?>{},
     bool prebuiltApplication = false,
     bool ipv6 = false,
-    String userIdentifier,
+    String? userIdentifier,
   }) async {
     if (await isSession) {
       globals.printTrace('Running on a session framework based build.');
@@ -356,7 +348,7 @@ class FuchsiaDevice extends Device {
     final Status status = globals.logger.startProgress(
       'Starting Fuchsia application $appName...',
     );
-    FuchsiaPackageServer fuchsiaPackageServer;
+    FuchsiaPackageServer? fuchsiaPackageServer;
     bool serverRegistered = false;
     String fuchsiaUrl;
     try {
@@ -379,7 +371,7 @@ class FuchsiaDevice extends Device {
 
       // Serve the flutter_runner.
       final File flutterRunnerArchive =
-          globals.fs.file(globals.artifacts.getArtifactPath(
+          globals.fs.file(globals.artifacts!.getArtifactPath(
         Artifact.fuchsiaFlutterRunner,
         platform: await targetPlatform,
         mode: debuggingOptions.buildInfo.mode,
@@ -455,7 +447,7 @@ class FuchsiaDevice extends Device {
     } finally {
       // Try to un-teach the package controller about the package server if
       // needed.
-      if (serverRegistered) {
+      if (serverRegistered && fuchsiaPackageServer != null) {
         await fuchsiaDeviceTools.pkgctl.rmRepo(this, fuchsiaPackageServer);
       }
       // Shutdown the package server and delete the package repo;
@@ -493,7 +485,7 @@ class FuchsiaDevice extends Device {
   @override
   Future<bool> stopApp(
     covariant FuchsiaApp app, {
-    String userIdentifier,
+    String? userIdentifier,
   }) async {
     if (await isSession) {
       // Currently there are no way to close a running app programmatically
@@ -510,11 +502,9 @@ class FuchsiaDevice extends Device {
     return true;
   }
 
-  TargetPlatform _targetPlatform;
-
   Future<TargetPlatform> _queryTargetPlatform() async {
     const TargetPlatform defaultTargetPlatform = TargetPlatform.fuchsia_arm64;
-    if (!globals.fuchsiaArtifacts.hasSshConfig) {
+    if (!globals.fuchsiaArtifacts!.hasSshConfig) {
       globals.printTrace('Could not determine Fuchsia target platform because '
           'Fuchsia ssh configuration is missing.\n'
           'Defaulting to arm64.');
@@ -574,12 +564,12 @@ class FuchsiaDevice extends Device {
   }
 
   @override
-  Future<TargetPlatform> get targetPlatform async => _targetPlatform ??= await _queryTargetPlatform();
+  late final Future<TargetPlatform> targetPlatform = _queryTargetPlatform();
 
   @override
   Future<String> get sdkNameAndVersion async {
     const String defaultName = 'Fuchsia';
-    if (!globals.fuchsiaArtifacts.hasSshConfig) {
+    if (!globals.fuchsiaArtifacts!.hasSshConfig) {
       globals.printTrace('Could not determine Fuchsia sdk name or version '
                  'because Fuchsia ssh configuration is missing.');
       return defaultName;
@@ -600,18 +590,18 @@ class FuchsiaDevice extends Device {
 
   @override
   DeviceLogReader getLogReader({
-    ApplicationPackage app,
+    ApplicationPackage? app,
     bool includePastLogs = false,
   }) {
     assert(!includePastLogs, 'Past log reading not supported on Fuchsia.');
     return _logReader ??= _FuchsiaLogReader(this, globals.systemClock, app);
   }
-  _FuchsiaLogReader _logReader;
+  _FuchsiaLogReader? _logReader;
 
   @override
   DevicePortForwarder get portForwarder =>
       _portForwarder ??= _FuchsiaPortForwarder(this);
-  DevicePortForwarder _portForwarder;
+  DevicePortForwarder? _portForwarder;
 
   @visibleForTesting
   set portForwarder(DevicePortForwarder forwarder) {
@@ -621,17 +611,12 @@ class FuchsiaDevice extends Device {
   @override
   void clearLogs() {}
 
-  bool _ipv6;
-
   /// [true] if the current host address is IPv6.
-  bool get ipv6 => _ipv6 ??= isIPv6Address(id);
+  late final bool ipv6 = isIPv6Address(id);
 
   /// Return the address that the device should use to communicate with the
   /// host.
-  Future<String> get hostAddress async {
-    if (_cachedHostAddress != null) {
-      return _cachedHostAddress;
-    }
+  late final Future<String> hostAddress = () async {
     final RunResult result = await shell(r'echo $SSH_CONNECTION');
     void fail() {
       throwToolExit('Failed to get local address, aborting.\n$result');
@@ -647,10 +632,8 @@ class FuchsiaDevice extends Device {
     if (addr.isEmpty) {
       fail();
     }
-    return _cachedHostAddress = addr;
-  }
-
-  String _cachedHostAddress;
+    return addr;
+  }();
 
   /// List the ports currently running a dart observatory.
   Future<List<int>> servicePorts() async {
@@ -679,7 +662,7 @@ class FuchsiaDevice extends Device {
         if (line == '') {
           continue;
         }
-        final int port = int.tryParse(line);
+        final int? port = int.tryParse(line);
         if (port != null) {
           ports.add(port);
         }
@@ -690,14 +673,15 @@ class FuchsiaDevice extends Device {
 
   /// Run `command` on the Fuchsia device shell.
   Future<RunResult> shell(String command) async {
-    if (globals.fuchsiaArtifacts.sshConfig == null) {
+    final File? sshConfig = globals.fuchsiaArtifacts?.sshConfig;
+    if (sshConfig == null) {
       throwToolExit('Cannot interact with device. No ssh config.\n'
                     'Try setting FUCHSIA_SSH_CONFIG or FUCHSIA_BUILD_DIR.');
     }
     return globals.processUtils.run(<String>[
       'ssh',
       '-F',
-      globals.fuchsiaArtifacts.sshConfig.absolute.path,
+      sshConfig.absolute.path,
       id, // Device's IP address.
       command,
     ]);
@@ -705,14 +689,15 @@ class FuchsiaDevice extends Device {
 
   /// Transfer the file [origin] from the device to [destination].
   Future<RunResult> scp(String origin, String destination) async {
-    if (globals.fuchsiaArtifacts.sshConfig == null) {
+    final File? sshConfig = globals.fuchsiaArtifacts!.sshConfig;
+    if (sshConfig == null) {
       throwToolExit('Cannot interact with device. No ssh config.\n'
                     'Try setting FUCHSIA_SSH_CONFIG or FUCHSIA_BUILD_DIR.');
     }
     return globals.processUtils.run(<String>[
       'scp',
       '-F',
-      globals.fuchsiaArtifacts.sshConfig.absolute.path,
+      sshConfig.absolute.path,
       '$id:$origin',
       destination,
     ]);
@@ -733,11 +718,13 @@ class FuchsiaDevice extends Device {
         final FlutterVmService vmService = await connectToVmService(uri, logger: globals.logger);
         final List<FlutterView> flutterViews = await vmService.getFlutterViews();
         for (final FlutterView flutterView in flutterViews) {
-          if (flutterView.uiIsolate == null) {
+          final vm_service.IsolateRef? uiIsolate = flutterView.uiIsolate;
+          if (uiIsolate == null) {
             continue;
           }
-          if (flutterView.uiIsolate.name.contains(isolateName)) {
-            return vmService.httpAddress.port;
+          final int? port = vmService.httpAddress?.port;
+          if (port != null && uiIsolate.name?.contains(isolateName) == true) {
+            return port;
           }
         }
       } on SocketException catch (err) {
@@ -780,12 +767,12 @@ class FuchsiaIsolateDiscoveryProtocol {
   final Future<void> Function(Device, Uri, bool) _ddsStarter;
   // whether to only poll once.
   final bool _pollOnce;
-  Timer _pollingTimer;
-  Status _status;
+  Timer? _pollingTimer;
+  Status? _status;
 
   FutureOr<Uri> get uri {
     if (_uri != null) {
-      return _uri;
+      return _uri!;
     }
     _status ??= globals.logger.startProgress(
       'Waiting for a connection from $_isolateName on ${_device.name}...',
@@ -797,7 +784,7 @@ class FuchsiaIsolateDiscoveryProtocol {
     });
   }
 
-  Uri _uri;
+  Uri? _uri;
 
   void dispose() {
     if (!_foundUri.isCompleted) {
@@ -812,7 +799,7 @@ class FuchsiaIsolateDiscoveryProtocol {
   Future<void> _findIsolate() async {
     final List<int> ports = await _device.servicePorts();
     for (final int port in ports) {
-      FlutterVmService service;
+      FlutterVmService? service;
       if (_ports.containsKey(port)) {
         service = _ports[port];
       } else {
@@ -820,30 +807,32 @@ class FuchsiaIsolateDiscoveryProtocol {
         try {
           final Uri uri = Uri.parse('http://[$_ipv6Loopback]:$localPort');
           await _ddsStarter(_device, uri, true);
-          service = await _vmServiceConnector(_device.dds.uri);
+          service = await _vmServiceConnector(_device.dds.uri!);
           _ports[port] = service;
         } on SocketException catch (err) {
           globals.printTrace('Failed to connect to $localPort: $err');
           continue;
         }
       }
-      final List<FlutterView> flutterViews = await service.getFlutterViews();
+      final List<FlutterView> flutterViews = await service?.getFlutterViews() ?? <FlutterView>[];
       for (final FlutterView flutterView in flutterViews) {
-        if (flutterView.uiIsolate == null) {
+        final vm_service.IsolateRef? uiIsolate = flutterView.uiIsolate;
+        if (uiIsolate == null) {
           continue;
         }
-        if (flutterView.uiIsolate.name.contains(_isolateName)) {
+        final int? port = service?.httpAddress?.port;
+        if (port != null && uiIsolate.name?.contains(_isolateName) == true) {
           _foundUri.complete(_device.ipv6
-              ? Uri.parse('http://[$_ipv6Loopback]:${service.httpAddress.port}/')
-              : Uri.parse('http://$_ipv4Loopback:${service.httpAddress.port}/'));
-          _status.stop();
+              ? Uri.parse('http://[$_ipv6Loopback]:$port/')
+              : Uri.parse('http://$_ipv4Loopback:$port/'));
+          _status?.stop();
           return;
         }
       }
     }
     if (_pollOnce) {
       _foundUri.completeError(Exception('Max iterations exceeded'));
-      _status.stop();
+      _status?.stop();
       return;
     }
     _pollingTimer = Timer(_pollDuration, _findIsolate);
@@ -857,18 +846,23 @@ class _FuchsiaPortForwarder extends DevicePortForwarder {
   final Map<int, Process> _processes = <int, Process>{};
 
   @override
-  Future<int> forward(int devicePort, {int hostPort}) async {
+  Future<int> forward(int devicePort, {int? hostPort}) async {
     hostPort ??= await globals.os.findFreePort();
     if (hostPort == 0) {
       throwToolExit('Failed to forward port $devicePort. No free host-side ports');
     }
+    final File? sshConfig = globals.fuchsiaArtifacts?.sshConfig;
+    if (sshConfig == null) {
+      throwToolExit('Cannot interact with device. No ssh config.\n'
+          'Try setting FUCHSIA_SSH_CONFIG or FUCHSIA_BUILD_DIR.');
+    }
     // Note: the provided command works around a bug in -N, see US-515
     // for more explanation.
     final List<String> command = <String>[
       'ssh',
       '-6',
       '-F',
-      globals.fuchsiaArtifacts.sshConfig.absolute.path,
+      sshConfig.absolute.path,
       '-nNT',
       '-vvv',
       '-f',
@@ -895,12 +889,17 @@ class _FuchsiaPortForwarder extends DevicePortForwarder {
   @override
   Future<void> unforward(ForwardedPort forwardedPort) async {
     _forwardedPorts.remove(forwardedPort);
-    final Process process = _processes.remove(forwardedPort.hostPort);
+    final Process? process = _processes.remove(forwardedPort.hostPort);
     process?.kill();
+    final File? sshConfig = globals.fuchsiaArtifacts?.sshConfig;
+    if (sshConfig == null) {
+      // Nothing to cancel.
+      return;
+    }
     final List<String> command = <String>[
       'ssh',
       '-F',
-      globals.fuchsiaArtifacts.sshConfig.absolute.path,
+      sshConfig.absolute.path,
       '-O',
       'cancel',
       '-vvv',

packages/flutter_tools/lib/src/fuchsia/pkgctl.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import '../base/process.dart';
 
 import 'fuchsia_device.dart';

packages/flutter_tools/lib/src/fuchsia/session_control.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import '../base/process.dart';
 
 import 'fuchsia_device.dart';

packages/flutter_tools/lib/src/fuchsia/tiles_ctl.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import '../base/process.dart';
 import '../globals.dart' as globals;
 
@@ -23,7 +21,7 @@ class FuchsiaTilesCtl {
   /// found.
   static Future<int> findAppKey(FuchsiaDevice device, String appName) async {
     final FuchsiaTilesCtl tilesCtl = fuchsiaDeviceTools.tilesCtl;
-    final Map<int, String> runningApps = await tilesCtl.list(device);
+    final Map<int, String>? runningApps = await tilesCtl.list(device);
     if (runningApps == null) {
       globals.printTrace('tiles_ctl is not running');
       return -1;
@@ -39,7 +37,7 @@ class FuchsiaTilesCtl {
   /// Ensures that tiles is running on the device.
   static Future<bool> ensureStarted(FuchsiaDevice device) async {
     final FuchsiaTilesCtl tilesCtl = fuchsiaDeviceTools.tilesCtl;
-    final Map<int, String> runningApps = await tilesCtl.list(device);
+    final Map<int, String>? runningApps = await tilesCtl.list(device);
     if (runningApps == null) {
       return tilesCtl.start(device);
     }
@@ -58,7 +56,7 @@ class FuchsiaTilesCtl {
   ///
   /// Returns an empty mapping if tiles_ctl is running but no apps are running.
   /// Returns null if tiles_ctl is not running.
-  Future<Map<int, String>> list(FuchsiaDevice device) async {
+  Future<Map<int, String>?> list(FuchsiaDevice device) async {
     // Output of tiles_ctl list has the format:
     // Found 1 tiles:
     // Tile key 1 url fuchsia-pkg://fuchsia.com/stocks#meta/stocks.cmx ...
@@ -75,9 +73,11 @@ class FuchsiaTilesCtl {
     for (final String line in result.stdout.split('\n')) {
       final List<String> words = line.split(' ');
       if (words.isNotEmpty && words[0] == 'Tile') {
-        final int key = int.tryParse(words[2]);
-        final String url = words[4];
-        tiles[key] = url;
+        final int? key = int.tryParse(words[2]);
+        if (key != null) {
+          final String url = words[4];
+          tiles[key] = url;
+        }
       }
     }
     return tiles;

packages/flutter_tools/test/general.shard/fuchsia/fuchsia_device_test.dart

@@ -91,7 +91,7 @@ void main() {
       final FakeFuchsiaWorkflow fuchsiaWorkflow = FakeFuchsiaWorkflow(canListDevices: false);
       final FuchsiaDevices fuchsiaDevices = FuchsiaDevices(
         platform: FakePlatform(),
-        fuchsiaSdk: null,
+        fuchsiaSdk: FakeFuchsiaSdk(devices: 'ignored'),
         fuchsiaWorkflow: fuchsiaWorkflow,
         logger: BufferLogger.test(),
       );
@@ -154,7 +154,7 @@ void main() {
 
     testUsingContext('disposing device disposes the portForwarder', () async {
       final FakePortForwarder portForwarder = FakePortForwarder();
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       device.portForwarder = portForwarder;
       await device.dispose();
 
@@ -162,7 +162,7 @@ void main() {
     });
 
     testWithoutContext('default capabilities', () async {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       final FlutterProject project = FlutterProject.fromDirectoryTest(memoryFileSystem.currentDirectory);
       memoryFileSystem.directory('fuchsia').createSync(recursive: true);
       memoryFileSystem.file('pubspec.yaml').createSync();
@@ -174,13 +174,13 @@ void main() {
     });
 
     test('is ephemeral', () {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(device.ephemeral, true);
     });
 
     testWithoutContext('supported for project', () async {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       final FlutterProject project = FlutterProject.fromDirectoryTest(memoryFileSystem.currentDirectory);
       memoryFileSystem.directory('fuchsia').createSync(recursive: true);
       memoryFileSystem.file('pubspec.yaml').createSync();
@@ -189,7 +189,7 @@ void main() {
     });
 
     testWithoutContext('not supported for project', () async {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       final FlutterProject project = FlutterProject.fromDirectoryTest(memoryFileSystem.currentDirectory);
       memoryFileSystem.file('pubspec.yaml').createSync();
 
@@ -197,7 +197,7 @@ void main() {
     });
 
     testUsingContext('targetPlatform does not throw when sshConfig is missing', () async {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(await device.targetPlatform, TargetPlatform.fuchsia_arm64);
     }, overrides: <Type, Generator>{
@@ -212,7 +212,7 @@ void main() {
         stdout: 'aarch64',
       ));
 
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       expect(await device.targetPlatform, TargetPlatform.fuchsia_arm64);
     }, overrides: <Type, Generator>{
       FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
@@ -226,7 +226,7 @@ void main() {
         stdout: 'x86_64',
       ));
 
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
       expect(await device.targetPlatform, TargetPlatform.fuchsia_x64);
     }, overrides: <Type, Generator>{
       FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
@@ -240,7 +240,7 @@ void main() {
         stdout: 'fe80::8c6c:2fff:fe3d:c5e1%ethp0003 50666 fe80::5054:ff:fe63:5e7a%ethp0003 22',
       ));
 
-      final FuchsiaDevice device = FuchsiaDevice('id');
+      final FuchsiaDevice device = FuchsiaDevice('id', name: 'device');
       expect(await device.hostAddress, 'fe80::8c6c:2fff:fe3d:c5e1%25ethp0003');
     }, overrides: <Type, Generator>{
       FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
@@ -254,7 +254,7 @@ void main() {
         exitCode: 1,
       ));
 
-      final FuchsiaDevice device = FuchsiaDevice('id');
+      final FuchsiaDevice device = FuchsiaDevice('id', name: 'device');
       await expectLater(() => device.hostAddress, throwsToolExit());
     }, overrides: <Type, Generator>{
       FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
@@ -267,7 +267,7 @@ void main() {
         command: <String>['ssh', '-F', '/ssh_config', 'id', r'echo $SSH_CONNECTION'],
       ));
 
-      final FuchsiaDevice device = FuchsiaDevice('id');
+      final FuchsiaDevice device = FuchsiaDevice('id', name: 'device');
       expect(() async => device.hostAddress, throwsToolExit());
     }, overrides: <Type, Generator>{
       FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
@@ -289,7 +289,7 @@ void main() {
       processManager.addCommand(const FakeCommand(
         command: <String>['ssh', '-F', '/artifact', 'id', 'find /hub -name vmservice-port'],
       ));
-      final FuchsiaDevice device = FuchsiaDevice('id');
+      final FuchsiaDevice device = FuchsiaDevice('id', name: 'device');
 
       await expectLater(device.servicePorts, throwsToolExit(message: 'No Dart Observatories found. Are you running a debug build?'));
     }, overrides: <Type, Generator>{
@@ -766,7 +766,7 @@ void main() {
     });
 
     testUsingContext('does not throw on non-existent ssh config', () async {
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(await device.sdkNameAndVersion, equals('Fuchsia'));
     }, overrides: <Type, Generator>{
@@ -780,7 +780,7 @@ void main() {
         command: <String>['ssh', '-F', '/ssh_config', '123', 'cat /pkgfs/packages/build-info/0/data/version'],
         stdout: 'version'
       ));
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(await device.sdkNameAndVersion, equals('Fuchsia version'));
     }, overrides: <Type, Generator>{
@@ -794,7 +794,7 @@ void main() {
         command: <String>['ssh', '-F', '/ssh_config', '123', 'cat /pkgfs/packages/build-info/0/data/version'],
         exitCode: 1,
       ));
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(await device.sdkNameAndVersion, equals('Fuchsia'));
     }, overrides: <Type, Generator>{
@@ -807,7 +807,7 @@ void main() {
       processManager.addCommand(const FakeCommand(
         command: <String>['ssh', '-F', '/ssh_config', '123', 'cat /pkgfs/packages/build-info/0/data/version'],
       ));
-      final FuchsiaDevice device = FuchsiaDevice('123');
+      final FuchsiaDevice device = FuchsiaDevice('123', name: 'device');
 
       expect(await device.sdkNameAndVersion, equals('Fuchsia'));
     }, overrides: <Type, Generator>{