Migrate some workflows and doctor validators to null safety (#79807)

packages/flutter_tools/lib/src/android/android_studio_validator.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 '../base/config.dart';
 import '../base/file_system.dart';
 import '../base/platform.dart';
@@ -16,7 +12,7 @@ import '../intellij/intellij.dart';
 import 'android_studio.dart';
 
 class AndroidStudioValidator extends DoctorValidator {
-  AndroidStudioValidator(this._studio, { @required FileSystem fileSystem })
+  AndroidStudioValidator(this._studio, { required FileSystem fileSystem })
     : _fileSystem = fileSystem,
       super('Android Studio');
 
@@ -40,14 +36,15 @@ class AndroidStudioValidator extends DoctorValidator {
     final List<ValidationMessage> messages = <ValidationMessage>[];
     ValidationType type = ValidationType.missing;
 
-    final String studioVersionText = _studio.version == Version.unknown
+    final String? studioVersionText = _studio.version == Version.unknown
       ? null
       : userMessages.androidStudioVersion(_studio.version.toString());
     messages.add(ValidationMessage(
       userMessages.androidStudioLocation(_studio.directory),
     ));
 
-    final IntelliJPlugins plugins = IntelliJPlugins(_studio.pluginsPath, fileSystem: _fileSystem);
+    if (_studio.pluginsPath != null) {
+      final IntelliJPlugins plugins = IntelliJPlugins(_studio.pluginsPath!, fileSystem: _fileSystem);
       plugins.validatePackage(
         messages,
         <String>['flutter-intellij', 'flutter-intellij.jar'],
@@ -61,6 +58,7 @@ class AndroidStudioValidator extends DoctorValidator {
         'Dart',
         IntelliJPlugins.kIntellijDartPluginUrl,
       );
+    }
 
     if (_studio.isValid) {
       type = _hasIssues(messages)
@@ -90,9 +88,9 @@ class AndroidStudioValidator extends DoctorValidator {
 
 class NoAndroidStudioValidator extends DoctorValidator {
   NoAndroidStudioValidator({
-    @required Config config,
-    @required Platform platform,
-    @required UserMessages userMessages,
+    required Config config,
+    required Platform platform,
+    required UserMessages userMessages,
   }) : _config = config,
        _platform = platform,
        _userMessages = userMessages,

packages/flutter_tools/lib/src/custom_devices/custom_device_workflow.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 '../doctor_validator.dart';
@@ -18,7 +16,7 @@ import '../features.dart';
 @immutable
 class CustomDeviceWorkflow implements Workflow {
   const CustomDeviceWorkflow({
-    @required FeatureFlags featureFlags
+    required FeatureFlags featureFlags
   }) : _featureFlags = featureFlags;
 
   final FeatureFlags _featureFlags;

packages/flutter_tools/lib/src/globals.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-import 'android/android_sdk.dart';
 import 'android/gradle_utils.dart';
 import 'artifacts.dart';
 import 'base/bot_detector.dart';
@@ -51,7 +50,6 @@ CocoaPodsValidator get cocoapodsValidator => context.get<CocoaPodsValidator>();
 
 LocalEngineLocator get localEngineLocator => context.get<LocalEngineLocator>();
 
-AndroidSdk get androidSdk => context.get<AndroidSdk>();
 CocoaPods get cocoaPods => context.get<CocoaPods>();
 FlutterVersion get flutterVersion => context.get<FlutterVersion>();
 FuchsiaArtifacts get fuchsiaArtifacts => context.get<FuchsiaArtifacts>();

packages/flutter_tools/lib/src/globals_null_migrated.dart

@@ -4,6 +4,7 @@
 
 import 'package:process/process.dart';
 
+import 'android/android_sdk.dart';
 import 'android/android_studio.dart';
 import 'base/config.dart';
 import 'base/context.dart';
@@ -28,6 +29,7 @@ Logger get logger => context.get<Logger>()!;
 OperatingSystemUtils get os => context.get<OperatingSystemUtils>()!;
 Signals get signals => context.get<Signals>() ?? LocalSignals.instance;
 AndroidStudio? get androidStudio => context.get<AndroidStudio>();
+AndroidSdk? get androidSdk => context.get<AndroidSdk>();
 
 /// Currently active implementation of the file system.
 ///

packages/flutter_tools/lib/src/intellij/intellij.dart

@@ -2,10 +2,7 @@
 // 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:archive/archive.dart';
-import 'package:meta/meta.dart';
 
 import '../base/file_system.dart';
 import '../base/version.dart';
@@ -41,7 +38,7 @@ import '../doctor_validator.dart';
 ///     plugin versions.
 class IntelliJPlugins {
   IntelliJPlugins(this.pluginsPath, {
-    @required FileSystem fileSystem
+    required FileSystem fileSystem
   }) : _fileSystem = fileSystem;
 
   final FileSystem _fileSystem;
@@ -56,15 +53,15 @@ class IntelliJPlugins {
     List<String> packageNames,
     String title,
     String url, {
-    Version minVersion,
+    Version? minVersion,
   }) {
     for (final String packageName in packageNames) {
       if (!_hasPackage(packageName)) {
         continue;
       }
 
-      final String versionText = _readPackageVersion(packageName);
-      final Version version = Version.parse(versionText);
+      final String? versionText = _readPackageVersion(packageName);
+      final Version? version = Version.parse(versionText);
       if (version != null && minVersion != null && version < minVersion) {
         messages.add(ValidationMessage.error(
           '$title plugin version $versionText - the recommended minimum version is $minVersion'),
@@ -90,7 +87,7 @@ class IntelliJPlugins {
     return _fileSystem.isDirectorySync(packagePath);
   }
 
-  ArchiveFile _findPluginXml(String packageName) {
+  ArchiveFile? _findPluginXml(String packageName) {
     final List<File> mainJarFileList = <File>[];
     if (packageName.endsWith('.jar')) {
       // package exists (checked in _hasPackage)
@@ -131,7 +128,7 @@ class IntelliJPlugins {
 
     for (final File file in mainJarFileList) {
       final Archive archive = ZipDecoder().decodeBytes(file.readAsBytesSync());
-      final ArchiveFile archiveFile = archive.findFile('META-INF/plugin.xml');
+      final ArchiveFile? archiveFile = archive.findFile('META-INF/plugin.xml');
       if (archiveFile != null) {
         return archiveFile;
       }
@@ -139,9 +136,9 @@ class IntelliJPlugins {
     return null;
   }
 
-  String _readPackageVersion(String packageName) {
+  String? _readPackageVersion(String packageName) {
     try {
-      final ArchiveFile archiveFile = _findPluginXml(packageName);
+      final ArchiveFile? archiveFile = _findPluginXml(packageName);
       if (archiveFile == null) {
         return null;
       }

packages/flutter_tools/lib/src/linux/linux_workflow.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 '../base/platform.dart';
 import '../doctor_validator.dart';
 import '../features.dart';
@@ -16,8 +12,8 @@ import '../features.dart';
 /// repository to the flutter repo.
 class LinuxWorkflow implements Workflow {
   const LinuxWorkflow({
-    @required Platform platform,
-    @required FeatureFlags featureFlags,
+    required Platform platform,
+    required FeatureFlags featureFlags,
   }) : _platform = platform,
        _featureFlags = featureFlags;
 

packages/flutter_tools/lib/src/macos/macos_workflow.dart

@@ -2,20 +2,15 @@
 // 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 '../base/platform.dart';
 import '../doctor_validator.dart';
 import '../features.dart';
 
-
 /// The macOS-specific implementation of a [Workflow].
 class MacOSWorkflow implements Workflow {
   const MacOSWorkflow({
-    @required Platform platform,
-    @required FeatureFlags featureFlags,
+    required Platform platform,
+    required FeatureFlags featureFlags,
   }) : _platform = platform,
        _featureFlags = featureFlags;
 

packages/flutter_tools/lib/src/proxy_validator.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 'base/platform.dart';
 import 'doctor_validator.dart';
 
@@ -15,7 +11,7 @@ import 'doctor_validator.dart';
 /// validated along with `NO_PROXY`.
 class ProxyValidator extends DoctorValidator {
   ProxyValidator({
-    @required Platform platform,
+    required Platform platform,
   })  : shouldShow = _getEnv('HTTP_PROXY', platform).isNotEmpty,
         _httpProxy = _getEnv('HTTP_PROXY', platform),
         _noProxy = _getEnv('NO_PROXY', platform),

packages/flutter_tools/lib/src/web/workflow.dart

@@ -2,18 +2,14 @@
 // 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 '../base/platform.dart';
 import '../doctor_validator.dart';
 import '../features.dart';
 
 class WebWorkflow extends Workflow {
   const WebWorkflow({
-    @required Platform platform,
-    @required FeatureFlags featureFlags,
+    required Platform platform,
+    required FeatureFlags featureFlags,
   }) : _platform = platform,
        _featureFlags = featureFlags;
 

packages/flutter_tools/lib/src/windows/visual_studio_validator.dart

@@ -2,21 +2,17 @@
 // 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 '../base/context.dart';
 import '../base/user_messages.dart' hide userMessages;
 import '../doctor_validator.dart';
 import 'visual_studio.dart';
 
-VisualStudioValidator get visualStudioValidator => context.get<VisualStudioValidator>();
+VisualStudioValidator? get visualStudioValidator => context.get<VisualStudioValidator>();
 
 class VisualStudioValidator extends DoctorValidator {
   const VisualStudioValidator({
-    @required VisualStudio visualStudio,
-    @required UserMessages userMessages,
+    required VisualStudio visualStudio,
+    required UserMessages userMessages,
   }) : _visualStudio = visualStudio,
        _userMessages = userMessages,
        super('Visual Studio - develop for Windows');
@@ -28,7 +24,7 @@ class VisualStudioValidator extends DoctorValidator {
   Future<ValidationResult> validate() async {
     final List<ValidationMessage> messages = <ValidationMessage>[];
     ValidationType status = ValidationType.missing;
-    String versionInfo;
+    String? versionInfo;
 
     if (_visualStudio.isInstalled) {
       status = ValidationType.installed;
@@ -46,7 +42,7 @@ class VisualStudioValidator extends DoctorValidator {
         messages.add(ValidationMessage(_userMessages.visualStudioIsPrerelease));
       }
 
-      final String windows10SdkVersion = _visualStudio.getWindows10SDKVersion();
+      final String? windows10SdkVersion = _visualStudio.getWindows10SDKVersion();
       if (windows10SdkVersion != null) {
         messages.add(ValidationMessage(_userMessages.windows10SdkVersion(windows10SdkVersion)));
       }

packages/flutter_tools/lib/src/windows/windows_workflow.dart

@@ -2,17 +2,13 @@
 // 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 '../base/context.dart';
 import '../base/platform.dart';
 import '../doctor_validator.dart';
 import '../features.dart';
 
 /// The [WindowsWorkflow] instance.
-WindowsWorkflow get windowsWorkflow => context.get<WindowsWorkflow>();
+WindowsWorkflow? get windowsWorkflow => context.get<WindowsWorkflow>();
 
 /// The Windows-specific implementation of a [Workflow].
 ///
@@ -20,8 +16,8 @@ WindowsWorkflow get windowsWorkflow => context.get<WindowsWorkflow>();
 /// desktop configuration setting to be enabled.
 class WindowsWorkflow implements Workflow {
   const WindowsWorkflow({
-    @required Platform platform,
-    @required FeatureFlags featureFlags,
+    required Platform platform,
+    required FeatureFlags featureFlags,
   }) : _platform = platform,
        _featureFlags = featureFlags;