Migrate mdns_discovery and ios simulator to null safety (#92124)

packages/flutter_tools/lib/src/context_runner.dart

@@ -44,7 +44,7 @@ import 'flutter_features.dart';
 import 'fuchsia/fuchsia_device.dart' show FuchsiaDeviceTools;
 import 'fuchsia/fuchsia_sdk.dart' show FuchsiaSdk, FuchsiaArtifacts;
 import 'fuchsia/fuchsia_workflow.dart' show FuchsiaWorkflow, fuchsiaWorkflow;
-import 'globals.dart' as globals;
+import 'globals_null_migrated.dart' as globals;
 import 'ios/ios_workflow.dart';
 import 'ios/iproxy.dart';
 import 'ios/simulators.dart';

packages/flutter_tools/lib/src/globals.dart

@@ -6,9 +6,7 @@
 
 import 'base/context.dart';
 import 'doctor.dart';
-import 'ios/simulators.dart';
 
 export 'globals_null_migrated.dart';
 
 Doctor get doctor => context.get<Doctor>();
-IOSSimulatorUtils get iosSimulatorUtils => context.get<IOSSimulatorUtils>();

packages/flutter_tools/lib/src/globals_null_migrated.dart

@@ -31,6 +31,7 @@ import 'device.dart';
 import 'fuchsia/fuchsia_sdk.dart';
 import 'ios/ios_workflow.dart';
 import 'ios/plist_parser.dart';
+import 'ios/simulators.dart';
 import 'ios/xcodeproj.dart';
 import 'macos/cocoapods.dart';
 import 'macos/cocoapods_validator.dart';
@@ -54,6 +55,7 @@ Config get config => context.get<Config>()!;
 CrashReporter? get crashReporter => context.get<CrashReporter>();
 DeviceManager? get deviceManager => context.get<DeviceManager>();
 HttpClientFactory? get httpClientFactory => context.get<HttpClientFactory>();
+IOSSimulatorUtils? get iosSimulatorUtils => context.get<IOSSimulatorUtils>();
 Logger get logger => context.get<Logger>()!;
 OperatingSystemUtils get os => context.get<OperatingSystemUtils>()!;
 Signals get signals => context.get<Signals>() ?? LocalSignals.instance;

packages/flutter_tools/lib/src/mdns_discovery.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 'package:meta/meta.dart';
 import 'package:multicast_dns/multicast_dns.dart';
 
@@ -24,9 +22,9 @@ class MDnsObservatoryDiscovery {
   /// automatically select which application to use if multiple are advertising
   /// Dart observatory ports.
   MDnsObservatoryDiscovery({
-    MDnsClient mdnsClient,
-    @required Logger logger,
-    @required Usage flutterUsage,
+    MDnsClient? mdnsClient,
+    required Logger logger,
+    required Usage flutterUsage,
   }): _client = mdnsClient ?? MDnsClient(),
       _logger = logger,
       _flutterUsage = flutterUsage;
@@ -38,7 +36,7 @@ class MDnsObservatoryDiscovery {
   @visibleForTesting
   static const String dartObservatoryName = '_dartobservatory._tcp.local';
 
-  static MDnsObservatoryDiscovery get instance => context.get<MDnsObservatoryDiscovery>();
+  static MDnsObservatoryDiscovery? get instance => context.get<MDnsObservatoryDiscovery>();
 
   /// Executes an mDNS query for a Dart Observatory.
   ///
@@ -59,7 +57,7 @@ class MDnsObservatoryDiscovery {
   /// it will return that instance's information regardless of what application
   /// the Observatory instance is for.
   @visibleForTesting
-  Future<MDnsObservatoryDiscoveryResult> query({String applicationId, int deviceVmservicePort}) async {
+  Future<MDnsObservatoryDiscoveryResult?> query({String? applicationId, int? deviceVmservicePort}) async {
     _logger.printTrace('Checking for advertised Dart observatories...');
     try {
       await _client.start();
@@ -78,7 +76,7 @@ class MDnsObservatoryDiscovery {
         .map<String>((PtrResourceRecord record) => record.domainName)
         .toSet();
 
-      String domainName;
+      String? domainName;
       if (applicationId != null) {
         for (final String name in uniqueDomainNames) {
           if (name.toLowerCase().startsWith(applicationId.toLowerCase())) {
@@ -93,7 +91,7 @@ class MDnsObservatoryDiscovery {
         final StringBuffer buffer = StringBuffer();
         buffer.writeln('There are multiple observatory ports available.');
         buffer.writeln('Rerun this command with one of the following passed in as the appId:');
-        buffer.writeln('');
+        buffer.writeln();
         for (final String uniqueDomainName in uniqueDomainNames) {
           buffer.writeln('  flutter attach --app-id ${uniqueDomainName.replaceAll('.$dartObservatoryName', '')}');
         }
@@ -120,15 +118,18 @@ class MDnsObservatoryDiscovery {
         .lookup<TxtResourceRecord>(
             ResourceRecordQuery.text(domainName),
         )
-        ?.toList();
+        .toList();
       if (txt == null || txt.isEmpty) {
         return MDnsObservatoryDiscoveryResult(srv.first.port, '');
       }
       const String authCodePrefix = 'authCode=';
-      final String raw = txt.first.text.split('\n').firstWhere(
-        (String s) => s.startsWith(authCodePrefix),
-        orElse: () => null,
-      );
+      String? raw;
+      for (final String record in txt.first.text.split('\n')) {
+        if (record.startsWith(authCodePrefix)) {
+          raw = record;
+          break;
+        }
+      }
       if (raw == null) {
         return MDnsObservatoryDiscoveryResult(srv.first.port, '');
       }
@@ -144,12 +145,12 @@ class MDnsObservatoryDiscovery {
     }
   }
 
-  Future<Uri> getObservatoryUri(String applicationId, Device device, {
+  Future<Uri?> getObservatoryUri(String applicationId, Device device, {
     bool usesIpv6 = false,
-    int hostVmservicePort,
-    int deviceVmservicePort,
+    int? hostVmservicePort,
+    int? deviceVmservicePort,
   }) async {
-    final MDnsObservatoryDiscoveryResult result = await query(
+    final MDnsObservatoryDiscoveryResult? result = await query(
       applicationId: applicationId,
       deviceVmservicePort: deviceVmservicePort,
     );
@@ -246,8 +247,8 @@ Future<Uri> buildObservatoryUri(
   Device device,
   String host,
   int devicePort, [
-  int hostVmservicePort,
-  String authCode,
+  int? hostVmservicePort,
+  String? authCode,
 ]) async {
   String path = '/';
   if (authCode != null) {
@@ -259,8 +260,8 @@ Future<Uri> buildObservatoryUri(
     path += '/';
   }
   hostVmservicePort ??= 0;
-  final int actualHostPort = hostVmservicePort == 0 ?
-    await device.portForwarder.forward(devicePort) :
+  final int? actualHostPort = hostVmservicePort == 0 ?
+    await device.portForwarder?.forward(devicePort) :
     hostVmservicePort;
   return Uri(scheme: 'http', host: host, port: actualHostPort, path: path);
 }

packages/flutter_tools/lib/src/sksl_writer.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 'dart:async';
 
 import 'package:file/file.dart';
@@ -15,9 +13,9 @@ import 'convert.dart';
 import 'device.dart';
 import 'globals_null_migrated.dart' as globals;
 
-Future<String> sharedSkSlWriter(Device device, Map<String, Object> data, {
-  File outputFile,
-  Logger logger,
+Future<String?> sharedSkSlWriter(Device device, Map<String, Object> data, {
+  File? outputFile,
+  Logger? logger,
 }) async {
   logger ??= globals.logger;
   if (data.isEmpty) {

packages/flutter_tools/test/general.shard/mdns_discovery_test.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 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/build_info.dart';
@@ -24,9 +22,9 @@ void main() {
     setUp(() {
       setNetworkInterfaceLister(
         ({
-          bool includeLoopback,
-          bool includeLinkLocal,
-          InternetAddressType type,
+          bool? includeLoopback,
+          bool? includeLinkLocal,
+          InternetAddressType? type,
         }) async => <NetworkInterface>[],
       );
     });
@@ -44,7 +42,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final int port = (await portDiscovery.query())?.port;
+      final int? port = (await portDiscovery.query())?.port;
       expect(port, isNull);
     });
 
@@ -56,7 +54,7 @@ void main() {
         logger: logger,
         flutterUsage: TestUsage(),
       );
-      final Uri uri = await portDiscovery.getObservatoryUri(
+      final Uri? uri = await portDiscovery.getObservatoryUri(
         '',
         FakeIOSDevice(),
       );
@@ -81,7 +79,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final int port = (await portDiscovery.query())?.port;
+      final int? port = (await portDiscovery.query())?.port;
       expect(port, 123);
     });
 
@@ -107,7 +105,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final MDnsObservatoryDiscoveryResult result = await portDiscovery.query();
+      final MDnsObservatoryDiscoveryResult? result = await portDiscovery.query();
       expect(result?.port, 123);
       expect(result?.authCode, 'xyz/');
     });
@@ -157,7 +155,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final int port = (await portDiscovery.query(applicationId: 'fiz'))?.port;
+      final int? port = (await portDiscovery.query(applicationId: 'fiz'))?.port;
       expect(port, 321);
     });
 
@@ -184,7 +182,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final int port = (await portDiscovery.query(applicationId: 'bar'))?.port;
+      final int? port = (await portDiscovery.query(applicationId: 'bar'))?.port;
       expect(port, 1234);
     });
 
@@ -199,7 +197,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final int port = (await portDiscovery.query(applicationId: 'bar'))?.port;
+      final int? port = (await portDiscovery.query(applicationId: 'bar'))?.port;
       expect(port, isNull);
     });
 
@@ -236,7 +234,7 @@ void main() {
         logger: BufferLogger.test(),
         flutterUsage: TestUsage(),
       );
-      final Uri uri = await portDiscovery.getObservatoryUri('bar', device, hostVmservicePort: 0);
+      final Uri? uri = await portDiscovery.getObservatoryUri('bar', device, hostVmservicePort: 0);
       expect(uri.toString(), 'http://127.0.0.1:123/');
     });
   });
@@ -255,10 +253,10 @@ class FakeMDnsClient extends Fake implements MDnsClient {
 
   @override
   Future<void> start({
-    InternetAddress listenAddress,
-    NetworkInterfacesFactory interfacesFactory,
+    InternetAddress? listenAddress,
+    NetworkInterfacesFactory? interfacesFactory,
     int mDnsPort = 5353,
-    InternetAddress mDnsAddress,
+    InternetAddress? mDnsAddress,
   }) async {
     if (osErrorOnStart) {
       throw const OSError('Operation not supported on socket', 102);