Migrate project.dart and all dependencies to null safety (#83817)

packages/flutter_tools/bin/fuchsia_asset_builder.dart

@@ -12,6 +12,7 @@ import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/depfile.dart';
 import 'package:flutter_tools/src/bundle.dart';
+import 'package:flutter_tools/src/bundle_builder.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/context_runner.dart';
 import 'package:flutter_tools/src/devfs.dart';

packages/flutter_tools/lib/src/android/android_builder.dart

@@ -2,16 +2,12 @@
 // 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 '../build_info.dart';
 import '../project.dart';
 
 /// The builder in the current context.
-AndroidBuilder get androidBuilder {
+AndroidBuilder? get androidBuilder {
   return context.get<AndroidBuilder>();
 }
 
@@ -19,25 +15,25 @@ abstract class AndroidBuilder {
   const AndroidBuilder();
   /// Builds an AAR artifact.
   Future<void> buildAar({
-    @required FlutterProject project,
-    @required Set<AndroidBuildInfo> androidBuildInfo,
-    @required String target,
-    @required String outputDirectoryPath,
-    @required String buildNumber,
+    required FlutterProject project,
+    required Set<AndroidBuildInfo> androidBuildInfo,
+    required String target,
+    String? outputDirectoryPath,
+    required String buildNumber,
   });
 
   /// Builds an APK artifact.
   Future<void> buildApk({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
+    required FlutterProject project,
+    required AndroidBuildInfo androidBuildInfo,
+    required String target,
   });
 
   /// Builds an App Bundle artifact.
   Future<void> buildAab({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
+    required FlutterProject project,
+    required AndroidBuildInfo androidBuildInfo,
+    required String target,
     bool validateDeferredComponents = true,
     bool deferredComponentsEnabled = false,
   });

packages/flutter_tools/lib/src/android/gradle_errors.dart

@@ -2,13 +2,12 @@
 // 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/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/process.dart';
-import '../globals.dart' as globals;
+import '../globals_null_migrated.dart' as globals;
 import '../project.dart';
 import '../reporting/reporting.dart';
 import 'android_studio.dart';
@@ -18,8 +17,8 @@ typedef GradleErrorTest = bool Function(String);
 /// A Gradle error handled by the tool.
 class GradleHandledError {
   const GradleHandledError({
-    @required this.test,
-    @required this.handler,
+    required this.test,
+    required this.handler,
     this.eventLabel,
   });
 
@@ -29,16 +28,16 @@ class GradleHandledError {
 
   /// The handler function.
   final Future<GradleBuildStatus> Function({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) handler;
 
   /// The [BuildEvent] label is named gradle-[eventLabel].
   /// If not empty, the build event is logged along with
   /// additional metadata such as the attempt number.
-  final String eventLabel;
+  final String? eventLabel;
 }
 
 /// The status of the Gradle build.
@@ -85,10 +84,10 @@ final GradleHandledError permissionDeniedErrorHandler = GradleHandledError(
     'Permission denied',
   ]),
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     globals.printStatus('${globals.logger.terminal.warningMark} Gradle does not have execution permission.', emphasis: true);
     globals.printStatus(
@@ -122,17 +121,17 @@ final GradleHandledError networkErrorHandler = GradleHandledError(
     'Gateway Time-out'
   ]),
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     globals.printError(
       '${globals.logger.terminal.warningMark} Gradle threw an error while downloading artifacts from the network. '
       'Retrying to download...'
     );
     try {
-      final String homeDir = globals.platform.environment['HOME'];
+      final String? homeDir = globals.platform.environment['HOME'];
       if (homeDir != null) {
         final Directory directory = globals.fs.directory(globals.fs.path.join(homeDir, '.gradle'));
         ErrorHandlingFileSystem.deleteIfExists(directory, recursive: true);
@@ -152,10 +151,10 @@ final GradleHandledError r8FailureHandler = GradleHandledError(
     'com.android.tools.r8',
   ]),
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     globals.printStatus('${globals.logger.terminal.warningMark} The shrinker may have failed to optimize the Java bytecode.', emphasis: true);
     globals.printStatus('To disable the shrinker, pass the `--no-shrink` flag to this command.', indent: 4);
@@ -191,10 +190,10 @@ final GradleHandledError androidXFailureHandler = GradleHandledError(
            _androidXFailureRegex.hasMatch(line);
   },
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     final bool hasPlugins = project.flutterPluginsFile.existsSync();
     if (!hasPlugins) {
@@ -259,21 +258,21 @@ final GradleHandledError licenseNotAcceptedHandler = GradleHandledError(
     'You have not accepted the license agreements of the following SDK components',
   ]),
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     const String licenseNotAcceptedMatcher =
       r'You have not accepted the license agreements of the following SDK components:\s*\[(.+)\]';
 
     final RegExp licenseFailure = RegExp(licenseNotAcceptedMatcher, multiLine: true);
     assert(licenseFailure != null);
-    final Match licenseMatch = licenseFailure.firstMatch(line);
+    final Match? licenseMatch = licenseFailure.firstMatch(line);
     globals.printStatus(
       '${globals.logger.terminal.warningMark} Unable to download needed Android SDK components, as the '
       'following licenses have not been accepted:\n'
-      '${licenseMatch.group(1)}\n\n'
+      '${licenseMatch?.group(1)}\n\n'
       'To resolve this, please run the following command in a Terminal:\n'
       'flutter doctor --android-licenses'
     );
@@ -293,14 +292,14 @@ final GradleHandledError flavorUndefinedHandler = GradleHandledError(
     return _undefinedTaskPattern.hasMatch(line);
   },
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     final RunResult tasksRunResult = await globals.processUtils.run(
       <String>[
-        globals.gradleUtils.getExecutable(project),
+        globals.gradleUtils!.getExecutable(project),
         'app:tasks' ,
         '--all',
         '--console=auto',
@@ -309,15 +308,15 @@ final GradleHandledError flavorUndefinedHandler = GradleHandledError(
       workingDirectory: project.android.hostAppGradleRoot.path,
       environment: <String, String>{
         if (javaPath != null)
-          'JAVA_HOME': javaPath,
+          'JAVA_HOME': javaPath!,
       },
     );
     // Extract build types and product flavors.
     final Set<String> variants = <String>{};
     for (final String task in tasksRunResult.stdout.split('\n')) {
-      final Match match = _assembleTaskPattern.matchAsPrefix(task);
+      final Match? match = _assembleTaskPattern.matchAsPrefix(task);
       if (match != null) {
-        final String variant = match.group(1).toLowerCase();
+        final String variant = match.group(1)!.toLowerCase();
         if (!variant.endsWith('test')) {
           variants.add(variant);
         }
@@ -366,32 +365,32 @@ final GradleHandledError minSdkVersion = GradleHandledError(
     return _minSdkVersionPattern.hasMatch(line);
   },
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     final File gradleFile = project.directory
         .childDirectory('android')
         .childDirectory('app')
         .childFile('build.gradle');
 
-    final Match minSdkVersionMatch = _minSdkVersionPattern.firstMatch(line);
-    assert(minSdkVersionMatch.groupCount == 3);
+    final Match? minSdkVersionMatch = _minSdkVersionPattern.firstMatch(line);
+    assert(minSdkVersionMatch?.groupCount == 3);
 
     final String bold = globals.logger.terminal.bolden(
       'Fix this issue by adding the following to the file ${gradleFile.path}:\n'
       'android {\n'
       '  defaultConfig {\n'
-      '    minSdkVersion ${minSdkVersionMatch.group(2)}\n'
+      '    minSdkVersion ${minSdkVersionMatch?.group(2)}\n'
       '  }\n'
       '}\n'
     );
     globals.printStatus(
       '\n'
-      'The plugin ${minSdkVersionMatch.group(3)} requires a higher Android SDK version.\n'
+      'The plugin ${minSdkVersionMatch?.group(3)} requires a higher Android SDK version.\n'
       '$bold\n'
-      "Note that your app won't be available to users running Android SDKs below ${minSdkVersionMatch.group(2)}.\n"
+      "Note that your app won't be available to users running Android SDKs below ${minSdkVersionMatch?.group(2)}.\n"
       'Alternatively, try to find a version of this plugin that supports these lower versions of the Android SDK.'
     );
     return GradleBuildStatus.exit;
@@ -407,10 +406,10 @@ final GradleHandledError transformInputIssue = GradleHandledError(
     return line.contains('https://issuetracker.google.com/issues/158753935');
   },
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     final File gradleFile = project.directory
         .childDirectory('android')
@@ -441,10 +440,10 @@ final GradleHandledError lockFileDepMissing = GradleHandledError(
     return line.contains('which is not part of the dependency lock state');
   },
   handler: ({
-    @required String line,
-    @required FlutterProject project,
-    @required bool usesAndroidX,
-    @required bool shouldBuildPluginAsAar,
+    required String line,
+    required FlutterProject project,
+    required bool usesAndroidX,
+    required bool shouldBuildPluginAsAar,
   }) async {
     final File gradleFile = project.directory
         .childDirectory('android')

packages/flutter_tools/lib/src/android/gradle_utils.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 '../base/common.dart';
@@ -29,11 +27,11 @@ final RegExp _androidPluginRegExp = RegExp(r'com\.android\.tools\.build:gradle:(
 /// or constructing a Gradle project.
 class GradleUtils {
   GradleUtils({
-    @required Platform platform,
-    @required Logger logger,
-    @required FileSystem fileSystem,
-    @required Cache cache,
-    @required OperatingSystemUtils operatingSystemUtils,
+    required Platform platform,
+    required Logger logger,
+    required FileSystem fileSystem,
+    required Cache cache,
+    required OperatingSystemUtils operatingSystemUtils,
   }) : _platform = platform,
        _logger = logger,
        _cache = cache,
@@ -120,22 +118,22 @@ String getGradleVersionForAndroidPlugin(Directory directory, Logger logger) {
     logger.printTrace("$buildFile doesn't provide an AGP version, assuming AGP version: $_defaultGradleVersion");
     return _defaultGradleVersion;
   }
-  final String androidPluginVersion = pluginMatches.first.group(1);
+  final String? androidPluginVersion = pluginMatches.first.group(1);
   logger.printTrace('$buildFile provides AGP version: $androidPluginVersion');
-  return getGradleVersionFor(androidPluginVersion);
+  return getGradleVersionFor(androidPluginVersion ?? 'unknown');
 }
 
 /// Returns true if [targetVersion] is within the range [min] and [max] inclusive.
 bool _isWithinVersionRange(
   String targetVersion, {
-  @required String min,
-  @required String max,
+  required String min,
+  required String max,
 }) {
   assert(min != null);
   assert(max != null);
-  final Version parsedTargetVersion = Version.parse(targetVersion);
-  final Version minVersion = Version.parse(min);
-  final Version maxVersion = Version.parse(max);
+  final Version? parsedTargetVersion = Version.parse(targetVersion);
+  final Version? minVersion = Version.parse(min);
+  final Version? maxVersion = Version.parse(max);
   return minVersion != null &&
       maxVersion != null &&
       parsedTargetVersion != null &&
@@ -193,8 +191,8 @@ String getGradleVersionFor(String androidPluginVersion) {
 /// If [requireAndroidSdk] is true (the default) and no Android SDK is found,
 /// this will fail with a [ToolExit].
 void updateLocalProperties({
-  @required FlutterProject project,
-  BuildInfo buildInfo,
+  required FlutterProject project,
+  BuildInfo? buildInfo,
   bool requireAndroidSdk = true,
 }) {
   if (requireAndroidSdk && globals.androidSdk == null) {
@@ -211,7 +209,7 @@ void updateLocalProperties({
     changed = true;
   }
 
-  void changeIfNecessary(String key, String value) {
+  void changeIfNecessary(String key, String? value) {
     if (settings.values[key] == value) {
       return;
     }
@@ -223,21 +221,21 @@ void updateLocalProperties({
     changed = true;
   }
 
-  final AndroidSdk androidSdk = globals.androidSdk;
+  final AndroidSdk? androidSdk = globals.androidSdk;
   if (androidSdk != null) {
     changeIfNecessary('sdk.dir', globals.fsUtils.escapePath(androidSdk.directory.path));
   }
 
-  changeIfNecessary('flutter.sdk', globals.fsUtils.escapePath(Cache.flutterRoot));
+  changeIfNecessary('flutter.sdk', globals.fsUtils.escapePath(Cache.flutterRoot!));
   if (buildInfo != null) {
     changeIfNecessary('flutter.buildMode', buildInfo.modeName);
-    final String buildName = validatedBuildNameForPlatform(
+    final String? buildName = validatedBuildNameForPlatform(
       TargetPlatform.android_arm,
       buildInfo.buildName ?? project.manifest.buildName,
       globals.logger,
     );
     changeIfNecessary('flutter.versionName', buildName);
-    final String buildNumber = validatedBuildNumberForPlatform(
+    final String? buildNumber = validatedBuildNumberForPlatform(
       TargetPlatform.android_arm,
       buildInfo.buildNumber ?? project.manifest.buildNumber,
       globals.logger,
@@ -255,7 +253,7 @@ void updateLocalProperties({
 /// Writes the path to the Android SDK, if known.
 void writeLocalProperties(File properties) {
   final SettingsFile settings = SettingsFile();
-  final AndroidSdk androidSdk = globals.androidSdk;
+  final AndroidSdk? androidSdk = globals.androidSdk;
   if (androidSdk != null) {
     settings.values['sdk.dir'] = globals.fsUtils.escapePath(androidSdk.directory.path);
   }

packages/flutter_tools/lib/src/bundle.dart

@@ -2,35 +2,21 @@
 // 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:convert/convert.dart';
 import 'package:crypto/crypto.dart';
-import 'package:meta/meta.dart';
-import 'package:pool/pool.dart';
 
-import 'asset.dart';
-import 'base/common.dart';
 import 'base/config.dart';
 import 'base/file_system.dart';
-import 'base/logger.dart';
 import 'build_info.dart';
-import 'build_system/build_system.dart';
-import 'build_system/depfile.dart';
-import 'build_system/targets/common.dart';
-import 'cache.dart';
 import 'convert.dart';
-import 'devfs.dart';
 import 'globals_null_migrated.dart' as globals;
-import 'project.dart';
 
 String get defaultMainPath => globals.fs.path.join('lib', 'main.dart');
-const String defaultAssetBasePath = '.';
 const String defaultManifestPath = 'pubspec.yaml';
 String get defaultDepfilePath => globals.fs.path.join(getBuildDirectory(), 'snapshot_blob.bin.d');
 
 String getDefaultApplicationKernelPath({
-  @required bool trackWidgetCreation,
+  required bool trackWidgetCreation,
 }) {
   return getKernelPathForTransformerOptions(
     globals.fs.path.join(getBuildDirectory(), 'app.dill'),
@@ -39,15 +25,15 @@ String getDefaultApplicationKernelPath({
 }
 
 String getDefaultCachedKernelPath({
-  @required bool trackWidgetCreation,
-  @required List<String> dartDefines,
-  @required List<String> extraFrontEndOptions,
-  FileSystem fileSystem,
-  Config config,
+  required bool trackWidgetCreation,
+  required List<String> dartDefines,
+  List<String> extraFrontEndOptions = const <String>[],
+  FileSystem? fileSystem,
+  Config? config,
 }) {
   final StringBuffer buffer = StringBuffer();
   buffer.writeAll(dartDefines);
-  buffer.writeAll(extraFrontEndOptions ?? <String>[]);
+  buffer.writeAll(extraFrontEndOptions);
   String buildPrefix = '';
   if (buffer.isNotEmpty) {
     final String output = buffer.toString();
@@ -65,7 +51,7 @@ String getDefaultCachedKernelPath({
 
 String getKernelPathForTransformerOptions(
   String path, {
-  @required bool trackWidgetCreation,
+  required bool trackWidgetCreation,
 }) {
   if (trackWidgetCreation) {
     path += '.track.dill';
@@ -74,151 +60,3 @@ String getKernelPathForTransformerOptions(
 }
 
 const String defaultPrivateKeyPath = 'privatekey.der';
-
-/// Provides a `build` method that builds the bundle.
-class BundleBuilder {
-  /// Builds the bundle for the given target platform.
-  ///
-  /// The default `mainPath` is `lib/main.dart`.
-  /// The default  `manifestPath` is `pubspec.yaml`
-  Future<void> build({
-    @required TargetPlatform platform,
-    @required BuildInfo buildInfo,
-    FlutterProject project,
-    String mainPath,
-    String manifestPath = defaultManifestPath,
-    String applicationKernelFilePath,
-    String depfilePath,
-    String assetDirPath,
-    @visibleForTesting BuildSystem buildSystem
-  }) async {
-    project ??= FlutterProject.current();
-    mainPath ??= defaultMainPath;
-    depfilePath ??= defaultDepfilePath;
-    assetDirPath ??= getAssetBuildDirectory();
-    buildSystem ??= globals.buildSystem;
-
-    // If the precompiled flag was not passed, force us into debug mode.
-    final Environment environment = Environment(
-      projectDir: project.directory,
-      outputDir: globals.fs.directory(assetDirPath),
-      buildDir: project.dartTool.childDirectory('flutter_build'),
-      cacheDir: globals.cache.getRoot(),
-      flutterRootDir: globals.fs.directory(Cache.flutterRoot),
-      engineVersion: globals.artifacts.isLocalEngine
-          ? null
-          : globals.flutterVersion.engineRevision,
-      defines: <String, String>{
-        // used by the KernelSnapshot target
-        kTargetPlatform: getNameForTargetPlatform(platform),
-        kTargetFile: mainPath,
-        kDeferredComponents: 'false',
-        ...buildInfo.toBuildSystemEnvironment(),
-      },
-      artifacts: globals.artifacts,
-      fileSystem: globals.fs,
-      logger: globals.logger,
-      processManager: globals.processManager,
-      platform: globals.platform,
-      generateDartPluginRegistry: true,
-    );
-    final Target target = buildInfo.mode == BuildMode.debug
-        ? const CopyFlutterBundle()
-        : const ReleaseCopyFlutterBundle();
-    final BuildResult result = await buildSystem.build(target, environment);
-
-    if (!result.success) {
-      for (final ExceptionMeasurement measurement in result.exceptions.values) {
-        globals.printError('Target ${measurement.target} failed: ${measurement.exception}',
-          stackTrace: measurement.fatal
-              ? measurement.stackTrace
-              : null,
-        );
-      }
-      throwToolExit('Failed to build bundle.');
-    }
-    if (depfilePath != null) {
-      final Depfile depfile = Depfile(result.inputFiles, result.outputFiles);
-      final File outputDepfile = globals.fs.file(depfilePath);
-      if (!outputDepfile.parent.existsSync()) {
-        outputDepfile.parent.createSync(recursive: true);
-      }
-      final DepfileService depfileService = DepfileService(
-        fileSystem: globals.fs,
-        logger: globals.logger,
-      );
-      depfileService.writeToFile(depfile, outputDepfile);
-    }
-
-    // Work around for flutter_tester placing kernel artifacts in odd places.
-    if (applicationKernelFilePath != null) {
-      final File outputDill = globals.fs.directory(assetDirPath).childFile('kernel_blob.bin');
-      if (outputDill.existsSync()) {
-        outputDill.copySync(applicationKernelFilePath);
-      }
-    }
-    return;
-  }
-}
-
-Future<AssetBundle> buildAssets({
-  String manifestPath,
-  String assetDirPath,
-  @required String packagesPath,
-  TargetPlatform targetPlatform,
-}) async {
-  assetDirPath ??= getAssetBuildDirectory();
-  packagesPath ??= globals.fs.path.absolute(packagesPath);
-
-  // Build the asset bundle.
-  final AssetBundle assetBundle = AssetBundleFactory.instance.createBundle();
-  final int result = await assetBundle.build(
-    manifestPath: manifestPath,
-    assetDirPath: assetDirPath,
-    packagesPath: packagesPath,
-    targetPlatform: targetPlatform,
-  );
-  if (result != 0) {
-    return null;
-  }
-
-  return assetBundle;
-}
-
-Future<void> writeBundle(
-  Directory bundleDir,
-  Map<String, DevFSContent> assetEntries,
-  { Logger loggerOverride }
-) async {
-  loggerOverride ??= globals.logger;
-  if (bundleDir.existsSync()) {
-    try {
-      bundleDir.deleteSync(recursive: true);
-    } on FileSystemException catch (err) {
-      loggerOverride.printError(
-        'Failed to clean up asset directory ${bundleDir.path}: $err\n'
-        'To clean build artifacts, use the command "flutter clean".'
-      );
-    }
-  }
-  bundleDir.createSync(recursive: true);
-
-  // Limit number of open files to avoid running out of file descriptors.
-  final Pool pool = Pool(64);
-  await Future.wait<void>(
-    assetEntries.entries.map<Future<void>>((MapEntry<String, DevFSContent> entry) async {
-      final PoolResource resource = await pool.request();
-      try {
-        // This will result in strange looking files, for example files with `/`
-        // on Windows or files that end up getting URI encoded such as `#.ext`
-        // to `%23.ext`.  However, we have to keep it this way since the
-        // platform channels in the framework will URI encode these values,
-        // and the native APIs will look for files this way.
-        final File file = globals.fs.file(globals.fs.path.join(bundleDir.path, entry.key));
-        file.parent.createSync(recursive: true);
-        await file.writeAsBytes(await entry.value.contentsAsBytes());
-      } finally {
-        resource.release();
-      }
-    }));
-}

packages/flutter_tools/lib/src/bundle_builder.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// 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:pool/pool.dart';
+
+import 'asset.dart' hide defaultManifestPath;
+import 'base/common.dart';
+import 'base/file_system.dart';
+import 'base/logger.dart';
+import 'build_info.dart';
+import 'build_system/build_system.dart';
+import 'build_system/depfile.dart';
+import 'build_system/targets/common.dart';
+import 'bundle.dart';
+import 'cache.dart';
+import 'devfs.dart';
+import 'globals_null_migrated.dart' as globals;
+import 'project.dart';
+
+
+/// Provides a `build` method that builds the bundle.
+class BundleBuilder {
+  /// Builds the bundle for the given target platform.
+  ///
+  /// The default `mainPath` is `lib/main.dart`.
+  /// The default  `manifestPath` is `pubspec.yaml`
+  Future<void> build({
+    @required TargetPlatform platform,
+    @required BuildInfo buildInfo,
+    FlutterProject project,
+    String mainPath,
+    String manifestPath = defaultManifestPath,
+    String applicationKernelFilePath,
+    String depfilePath,
+    String assetDirPath,
+    @visibleForTesting BuildSystem buildSystem
+  }) async {
+    project ??= FlutterProject.current();
+    mainPath ??= defaultMainPath;
+    depfilePath ??= defaultDepfilePath;
+    assetDirPath ??= getAssetBuildDirectory();
+    buildSystem ??= globals.buildSystem;
+
+    // If the precompiled flag was not passed, force us into debug mode.
+    final Environment environment = Environment(
+      projectDir: project.directory,
+      outputDir: globals.fs.directory(assetDirPath),
+      buildDir: project.dartTool.childDirectory('flutter_build'),
+      cacheDir: globals.cache.getRoot(),
+      flutterRootDir: globals.fs.directory(Cache.flutterRoot),
+      engineVersion: globals.artifacts.isLocalEngine
+          ? null
+          : globals.flutterVersion.engineRevision,
+      defines: <String, String>{
+        // used by the KernelSnapshot target
+        kTargetPlatform: getNameForTargetPlatform(platform),
+        kTargetFile: mainPath,
+        kDeferredComponents: 'false',
+        ...buildInfo.toBuildSystemEnvironment(),
+      },
+      artifacts: globals.artifacts,
+      fileSystem: globals.fs,
+      logger: globals.logger,
+      processManager: globals.processManager,
+      platform: globals.platform,
+      generateDartPluginRegistry: true,
+    );
+    final Target target = buildInfo.mode == BuildMode.debug
+        ? const CopyFlutterBundle()
+        : const ReleaseCopyFlutterBundle();
+    final BuildResult result = await buildSystem.build(target, environment);
+
+    if (!result.success) {
+      for (final ExceptionMeasurement measurement in result.exceptions.values) {
+        globals.printError('Target ${measurement.target} failed: ${measurement.exception}',
+          stackTrace: measurement.fatal
+              ? measurement.stackTrace
+              : null,
+        );
+      }
+      throwToolExit('Failed to build bundle.');
+    }
+    if (depfilePath != null) {
+      final Depfile depfile = Depfile(result.inputFiles, result.outputFiles);
+      final File outputDepfile = globals.fs.file(depfilePath);
+      if (!outputDepfile.parent.existsSync()) {
+        outputDepfile.parent.createSync(recursive: true);
+      }
+      final DepfileService depfileService = DepfileService(
+        fileSystem: globals.fs,
+        logger: globals.logger,
+      );
+      depfileService.writeToFile(depfile, outputDepfile);
+    }
+
+    // Work around for flutter_tester placing kernel artifacts in odd places.
+    if (applicationKernelFilePath != null) {
+      final File outputDill = globals.fs.directory(assetDirPath).childFile('kernel_blob.bin');
+      if (outputDill.existsSync()) {
+        outputDill.copySync(applicationKernelFilePath);
+      }
+    }
+    return;
+  }
+}
+
+Future<AssetBundle> buildAssets({
+  String manifestPath,
+  String assetDirPath,
+  @required String packagesPath,
+  TargetPlatform targetPlatform,
+}) async {
+  assetDirPath ??= getAssetBuildDirectory();
+  packagesPath ??= globals.fs.path.absolute(packagesPath);
+
+  // Build the asset bundle.
+  final AssetBundle assetBundle = AssetBundleFactory.instance.createBundle();
+  final int result = await assetBundle.build(
+    manifestPath: manifestPath,
+    assetDirPath: assetDirPath,
+    packagesPath: packagesPath,
+    targetPlatform: targetPlatform,
+  );
+  if (result != 0) {
+    return null;
+  }
+
+  return assetBundle;
+}
+
+Future<void> writeBundle(
+  Directory bundleDir,
+  Map<String, DevFSContent> assetEntries,
+  { Logger loggerOverride }
+) async {
+  loggerOverride ??= globals.logger;
+  if (bundleDir.existsSync()) {
+    try {
+      bundleDir.deleteSync(recursive: true);
+    } on FileSystemException catch (err) {
+      loggerOverride.printError(
+        'Failed to clean up asset directory ${bundleDir.path}: $err\n'
+        'To clean build artifacts, use the command "flutter clean".'
+      );
+    }
+  }
+  bundleDir.createSync(recursive: true);
+
+  // Limit number of open files to avoid running out of file descriptors.
+  final Pool pool = Pool(64);
+  await Future.wait<void>(
+    assetEntries.entries.map<Future<void>>((MapEntry<String, DevFSContent> entry) async {
+      final PoolResource resource = await pool.request();
+      try {
+        // This will result in strange looking files, for example files with `/`
+        // on Windows or files that end up getting URI encoded such as `#.ext`
+        // to `%23.ext`.  However, we have to keep it this way since the
+        // platform channels in the framework will URI encode these values,
+        // and the native APIs will look for files this way.
+        final File file = globals.fs.file(globals.fs.path.join(bundleDir.path, entry.key));
+        file.parent.createSync(recursive: true);
+        await file.writeAsBytes(await entry.value.contentsAsBytes());
+      } finally {
+        resource.release();
+      }
+    }));
+}

packages/flutter_tools/lib/src/cmake.dart

@@ -2,21 +2,19 @@
 // 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/file_system.dart';
 import 'project.dart';
 
 /// Extracts the `BINARY_NAME` from a project's CMake file.
 ///
 /// Returns `null` if it cannot be found.
-String getCmakeExecutableName(CmakeBasedProject project) {
+String? getCmakeExecutableName(CmakeBasedProject project) {
   if (!project.cmakeFile.existsSync()) {
     return null;
   }
   final RegExp nameSetPattern = RegExp(r'^\s*set\(BINARY_NAME\s*"(.*)"\s*\)\s*$');
   for (final String line in project.cmakeFile.readAsLinesSync()) {
-    final RegExpMatch match = nameSetPattern.firstMatch(line);
+    final RegExpMatch? match = nameSetPattern.firstMatch(line);
     if (match != null) {
       return match.group(1);
     }
@@ -27,13 +25,13 @@ String getCmakeExecutableName(CmakeBasedProject project) {
 /// Extracts the `PACKAGE_GUID` from a project's CMake file.
 ///
 /// Returns `null` if it cannot be found.
-String getCmakePackageGuid(File cmakeFile) {
+String? getCmakePackageGuid(File cmakeFile) {
   if (!cmakeFile.existsSync()) {
     return null;
   }
   final RegExp nameSetPattern = RegExp(r'^\s*set\(PACKAGE_GUID\s*"(.*)"\s*\)\s*$');
   for (final String line in cmakeFile.readAsLinesSync()) {
-    final RegExpMatch match = nameSetPattern.firstMatch(line);
+    final RegExpMatch? match = nameSetPattern.firstMatch(line);
     if (match != null) {
       return match.group(1);
     }

packages/flutter_tools/lib/src/commands/build_bundle.dart

@@ -7,6 +7,7 @@
 import '../base/common.dart';
 import '../build_info.dart';
 import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../features.dart';
 import '../globals_null_migrated.dart' as globals;
 import '../project.dart';

packages/flutter_tools/lib/src/commands/test.dart

@@ -12,7 +12,7 @@ import '../asset.dart';
 import '../base/common.dart';
 import '../base/file_system.dart';
 import '../build_info.dart';
-import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../devfs.dart';
 import '../device.dart';
 import '../globals_null_migrated.dart' as globals;

packages/flutter_tools/lib/src/custom_devices/custom_device.dart

@@ -18,6 +18,7 @@ import '../base/process.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../convert.dart';
 import '../device.dart';
 import '../device_port_forwarder.dart';

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

@@ -13,7 +13,7 @@ import '../base/file_system.dart';
 import '../base/logger.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
-import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../convert.dart';
 import '../devfs.dart';
 import '../globals_null_migrated.dart' as globals;

packages/flutter_tools/lib/src/globals.dart

@@ -4,17 +4,13 @@
 
 // @dart = 2.8
 
-import 'android/gradle_utils.dart';
 import 'base/context.dart';
 import 'device.dart';
 import 'doctor.dart';
 import 'fuchsia/fuchsia_sdk.dart';
-import 'globals_null_migrated.dart' as globals;
 import 'ios/simulators.dart';
-import 'macos/cocoapods.dart';
 import 'macos/cocoapods_validator.dart';
 import 'macos/xcdevice.dart';
-import 'project.dart';
 import 'reporting/crash_reporting.dart';
 import 'runner/local_engine.dart';
 
@@ -24,22 +20,10 @@ CrashReporter get crashReporter => context.get<CrashReporter>();
 Doctor get doctor => context.get<Doctor>();
 DeviceManager get deviceManager => context.get<DeviceManager>();
 
-FlutterProjectFactory get projectFactory {
-  return context.get<FlutterProjectFactory>() ?? FlutterProjectFactory(
-    logger: globals.logger,
-    fileSystem: globals.fs,
-  );
-}
-
 CocoaPodsValidator get cocoapodsValidator => context.get<CocoaPodsValidator>();
 
 LocalEngineLocator get localEngineLocator => context.get<LocalEngineLocator>();
-
-CocoaPods get cocoaPods => context.get<CocoaPods>();
 FuchsiaArtifacts get fuchsiaArtifacts => context.get<FuchsiaArtifacts>();
 IOSSimulatorUtils get iosSimulatorUtils => context.get<IOSSimulatorUtils>();
 
 XCDevice get xcdevice => context.get<XCDevice>();
-
-/// Gradle utils in the current [AppContext].
-GradleUtils get gradleUtils => context.get<GradleUtils>();

packages/flutter_tools/lib/src/globals_null_migrated.dart

@@ -6,6 +6,7 @@ import 'package:process/process.dart';
 
 import 'android/android_sdk.dart';
 import 'android/android_studio.dart';
+import 'android/gradle_utils.dart';
 import 'artifacts.dart';
 import 'base/bot_detector.dart';
 import 'base/config.dart';
@@ -28,8 +29,10 @@ import 'cache.dart';
 import 'ios/ios_workflow.dart';
 import 'ios/plist_parser.dart';
 import 'ios/xcodeproj.dart';
+import 'macos/cocoapods.dart';
 import 'macos/xcode.dart';
 import 'persistent_tool_state.dart';
+import 'project.dart';
 import 'reporting/reporting.dart';
 import 'version.dart';
 
@@ -196,3 +199,15 @@ LocalFileSystem get localFileSystem => _instance ??= LocalFileSystem(
   Signals.defaultExitSignals,
   shutdownHooks,
 );
+
+/// Gradle utils in the current [AppContext].
+GradleUtils? get gradleUtils => context.get<GradleUtils>();
+
+CocoaPods? get cocoaPods => context.get<CocoaPods>();
+
+FlutterProjectFactory get projectFactory {
+  return context.get<FlutterProjectFactory>() ?? FlutterProjectFactory(
+    logger: logger,
+    fileSystem: fs,
+  );
+}

packages/flutter_tools/lib/src/ios/xcode_build_settings.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 '../base/file_system.dart';
 import '../build_info.dart';
@@ -33,11 +29,11 @@ String flutterMacOSFrameworkDir(BuildMode mode, FileSystem fileSystem,
 /// targetOverride: Optional parameter, if null or unspecified the default value
 /// from xcode_backend.sh is used 'lib/main.dart'.
 Future<void> updateGeneratedXcodeProperties({
-  @required FlutterProject project,
-  @required BuildInfo buildInfo,
-  String targetOverride,
+  required FlutterProject project,
+  required BuildInfo buildInfo,
+  String? targetOverride,
   bool useMacOSConfig = false,
-  String buildDirOverride,
+  String? buildDirOverride,
 }) async {
   final List<String> xcodeBuildSettings = _xcodeBuildSettingsLines(
     project: project,
@@ -64,8 +60,8 @@ Future<void> updateGeneratedXcodeProperties({
 /// for Xcode targets that need them.
 /// See [XcodeBasedProject.generatedXcodePropertiesFile].
 void _updateGeneratedXcodePropertiesFile({
-  @required FlutterProject project,
-  @required List<String> xcodeBuildSettings,
+  required FlutterProject project,
+  required List<String> xcodeBuildSettings,
   bool useMacOSConfig = false,
 }) {
   final StringBuffer localsBuffer = StringBuffer();
@@ -84,8 +80,8 @@ void _updateGeneratedXcodePropertiesFile({
 /// as flags for Flutter tools.
 /// See [XcodeBasedProject.generatedEnvironmentVariableExportScript].
 void _updateGeneratedEnvironmentVariablesScript({
-  @required FlutterProject project,
-  @required List<String> xcodeBuildSettings,
+  required FlutterProject project,
+  required List<String> xcodeBuildSettings,
   bool useMacOSConfig = false,
 }) {
   final StringBuffer localsBuffer = StringBuffer();
@@ -107,21 +103,21 @@ void _updateGeneratedEnvironmentVariablesScript({
 }
 
 /// Build name parsed and validated from build info and manifest. Used for CFBundleShortVersionString.
-String parsedBuildName({
-  @required FlutterManifest manifest,
-  BuildInfo buildInfo,
+String? parsedBuildName({
+  required FlutterManifest manifest,
+  BuildInfo? buildInfo,
 }) {
-  final String buildNameToParse = buildInfo?.buildName ?? manifest.buildName;
+  final String? buildNameToParse = buildInfo?.buildName ?? manifest.buildName;
   return validatedBuildNameForPlatform(TargetPlatform.ios, buildNameToParse, globals.logger);
 }
 
 /// Build number parsed and validated from build info and manifest. Used for CFBundleVersion.
-String parsedBuildNumber({
-  @required FlutterManifest manifest,
-  BuildInfo buildInfo,
+String? parsedBuildNumber({
+  required FlutterManifest manifest,
+  BuildInfo? buildInfo,
 }) {
-  String buildNumberToParse = buildInfo?.buildNumber ?? manifest.buildNumber;
-  final String buildNumber = validatedBuildNumberForPlatform(
+  String? buildNumberToParse = buildInfo?.buildNumber ?? manifest.buildNumber;
+  final String? buildNumber = validatedBuildNumberForPlatform(
     TargetPlatform.ios,
     buildNumberToParse,
     globals.logger,
@@ -141,15 +137,15 @@ String parsedBuildNumber({
 
 /// List of lines of build settings. Example: 'FLUTTER_BUILD_DIR=build'
 List<String> _xcodeBuildSettingsLines({
-  @required FlutterProject project,
-  @required BuildInfo buildInfo,
-  String targetOverride,
+  required FlutterProject project,
+  required BuildInfo buildInfo,
+  String? targetOverride,
   bool useMacOSConfig = false,
-  String buildDirOverride,
+  String? buildDirOverride,
 }) {
   final List<String> xcodeBuildSettings = <String>[];
 
-  final String flutterRoot = globals.fs.path.normalize(Cache.flutterRoot);
+  final String flutterRoot = globals.fs.path.normalize(Cache.flutterRoot!);
   xcodeBuildSettings.add('FLUTTER_ROOT=$flutterRoot');
 
   // This holds because requiresProjectRoot is true for this command
@@ -173,7 +169,7 @@ List<String> _xcodeBuildSettingsLines({
   final String buildNumber = parsedBuildNumber(manifest: project.manifest, buildInfo: buildInfo) ?? '1';
   xcodeBuildSettings.add('FLUTTER_BUILD_NUMBER=$buildNumber');
 
-  final Artifacts artifacts = globals.artifacts;
+  final Artifacts? artifacts = globals.artifacts;
   if (artifacts is LocalEngineArtifacts) {
     final LocalEngineArtifacts localEngineArtifacts = artifacts;
     final String engineOutPath = localEngineArtifacts.engineOutPath;

packages/flutter_tools/lib/src/isolated/devfs_web.dart

@@ -29,7 +29,7 @@ import '../base/net.dart';
 import '../base/platform.dart';
 import '../build_info.dart';
 import '../build_system/targets/web.dart';
-import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../cache.dart';
 import '../compile.dart';
 import '../convert.dart';

packages/flutter_tools/lib/src/macos/cocoapods.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:file/file.dart';
-import 'package:meta/meta.dart';
 import 'package:process/process.dart';
 
 import '../base/common.dart';
@@ -85,12 +82,12 @@ const Version cocoaPodsRecommendedVersion = Version.withText(1, 10, 0, '1.10.0')
 ///     installing iOS/macOS dependencies.
 class CocoaPods {
   CocoaPods({
-    @required FileSystem fileSystem,
-    @required ProcessManager processManager,
-    @required XcodeProjectInterpreter xcodeProjectInterpreter,
-    @required Logger logger,
-    @required Platform platform,
-    @required Usage usage,
+    required FileSystem fileSystem,
+    required ProcessManager processManager,
+    required XcodeProjectInterpreter xcodeProjectInterpreter,
+    required Logger logger,
+    required Platform platform,
+    required Usage usage,
   }) : _fileSystem = fileSystem,
       _processManager = processManager,
       _xcodeProjectInterpreter = xcodeProjectInterpreter,
@@ -112,33 +109,33 @@ class CocoaPods {
   final Logger _logger;
   final Usage _usage;
 
-  Future<String> _versionText;
+  Future<String?>? _versionText;
 
   Future<bool> get isInstalled =>
     _processUtils.exitsHappy(<String>['which', 'pod']);
 
-  Future<String> get cocoaPodsVersionText {
+  Future<String?> get cocoaPodsVersionText {
     _versionText ??= _processUtils.run(
       <String>['pod', '--version'],
       environment: <String, String>{
         'LANG': 'en_US.UTF-8',
       },
-    ).then<String>((RunResult result) {
+    ).then<String?>((RunResult result) {
       return result.exitCode == 0 ? result.stdout.trim() : null;
     }, onError: (dynamic _) => null);
-    return _versionText;
+    return _versionText!;
   }
 
   Future<CocoaPodsStatus> get evaluateCocoaPodsInstallation async {
     if (!(await isInstalled)) {
       return CocoaPodsStatus.notInstalled;
     }
-    final String versionText = await cocoaPodsVersionText;
+    final String? versionText = await cocoaPodsVersionText;
     if (versionText == null) {
       return CocoaPodsStatus.brokenInstall;
     }
     try {
-      final Version installedVersion = Version.parse(versionText);
+      final Version? installedVersion = Version.parse(versionText);
       if (installedVersion == null) {
         return CocoaPodsStatus.unknownVersion;
       }
@@ -155,8 +152,8 @@ class CocoaPods {
   }
 
   Future<bool> processPods({
-    @required XcodeBasedProject xcodeProject,
-    @required BuildMode buildMode,
+    required XcodeBasedProject xcodeProject,
+    required BuildMode buildMode,
     bool dependenciesChanged = true,
   }) async {
     if (!xcodeProject.podfile.existsSync()) {
@@ -253,7 +250,7 @@ class CocoaPods {
       podfileTemplateName = isSwift ? 'Podfile-ios-swift' : 'Podfile-ios-objc';
     }
     final File podfileTemplate = _fileSystem.file(_fileSystem.path.join(
-      Cache.flutterRoot,
+      Cache.flutterRoot!,
       'packages',
       'flutter_tools',
       'templates',
@@ -391,7 +388,7 @@ class CocoaPods {
       //
       // Warn the user if they are still symlinking to the framework.
       final Link flutterSymlink = _fileSystem.link(_fileSystem.path.join(
-        (xcodeProject as IosProject).symlinks.path,
+        xcodeProject.symlinks.path,
         'flutter',
       ));
       if (flutterSymlink.existsSync()) {

packages/flutter_tools/lib/src/tester/flutter_tester.dart

@@ -18,6 +18,7 @@ import '../base/logger.dart';
 import '../base/os.dart';
 import '../build_info.dart';
 import '../bundle.dart';
+import '../bundle_builder.dart';
 import '../desktop_device.dart';
 import '../devfs.dart';
 import '../device.dart';

packages/flutter_tools/test/commands.shard/permeable/build_bundle_test.dart

@@ -10,6 +10,7 @@ import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/bundle.dart';
+import 'package:flutter_tools/src/bundle_builder.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/build_bundle.dart';
 import 'package:flutter_tools/src/features.dart';

packages/flutter_tools/test/general.shard/android/gradle_find_bundle_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:file/memory.dart';
 import 'package:flutter_tools/src/android/gradle.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
@@ -15,7 +13,7 @@ import 'package:flutter_tools/src/reporting/reporting.dart';
 import '../../src/common.dart';
 
 void main() {
-  FileSystem fileSystem;
+  late FileSystem fileSystem;
 
   setUp(() {
     fileSystem = MemoryFileSystem.test();

packages/flutter_tools/test/general.shard/android/gradle_utils_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:file/memory.dart';
 import 'package:flutter_tools/src/android/gradle_utils.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
@@ -17,9 +15,9 @@ import '../../src/fakes.dart';
 
 void main() {
    group('injectGradleWrapperIfNeeded', () {
-    MemoryFileSystem fileSystem;
-    Directory gradleWrapperDirectory;
-    GradleUtils gradleUtils;
+    late MemoryFileSystem fileSystem;
+    late Directory gradleWrapperDirectory;
+    late GradleUtils gradleUtils;
 
     setUp(() {
       fileSystem = MemoryFileSystem.test();

packages/flutter_tools/test/general.shard/android_plugin_test.dart

@@ -2,13 +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 'package:file/file.dart';
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/platform_plugins.dart';
 
-
 import '../src/common.dart';
 
 void main() {

packages/flutter_tools/test/general.shard/asset_bundle_test.dart

@@ -11,7 +11,7 @@ import 'package:file/memory.dart';
 import 'package:flutter_tools/src/asset.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/platform.dart';
-import 'package:flutter_tools/src/bundle.dart';
+import 'package:flutter_tools/src/bundle_builder.dart';
 import 'package:flutter_tools/src/devfs.dart';
 import 'package:flutter_tools/src/globals_null_migrated.dart' as globals;
 

packages/flutter_tools/test/general.shard/bundle_builder_test.dart

@@ -8,7 +8,7 @@ import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
-import 'package:flutter_tools/src/bundle.dart';
+import 'package:flutter_tools/src/bundle_builder.dart';
 import 'package:flutter_tools/src/globals_null_migrated.dart' as globals;
 import 'package:flutter_tools/src/project.dart';
 

packages/flutter_tools/test/general.shard/custom_devices/custom_device_test.dart

@@ -13,6 +13,7 @@ import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/bundle.dart';
+import 'package:flutter_tools/src/bundle_builder.dart';
 import 'package:flutter_tools/src/convert.dart';
 import 'package:flutter_tools/src/custom_devices/custom_device.dart';
 import 'package:flutter_tools/src/custom_devices/custom_device_config.dart';

packages/flutter_tools/test/src/android_common.dart

@@ -2,39 +2,35 @@
 // 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/android/android_builder.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/globals_null_migrated.dart' as globals;
 import 'package:flutter_tools/src/project.dart';
 
-import 'package:meta/meta.dart';
-
 /// A fake implementation of [AndroidBuilder].
 class FakeAndroidBuilder implements AndroidBuilder {
   @override
   Future<void> buildAar({
-    @required FlutterProject project,
-    @required Set<AndroidBuildInfo> androidBuildInfo,
-    @required String target,
-    @required String outputDirectoryPath,
-    @required String buildNumber,
+    required FlutterProject project,
+    required Set<AndroidBuildInfo> androidBuildInfo,
+    required String target,
+    String? outputDirectoryPath,
+    required String buildNumber,
   }) async {}
 
   @override
   Future<void> buildApk({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
+    required FlutterProject project,
+    required AndroidBuildInfo androidBuildInfo,
+    required String target,
   }) async {}
 
   @override
   Future<void> buildAab({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
+    required FlutterProject project,
+    required AndroidBuildInfo androidBuildInfo,
+    required String target,
     bool validateDeferredComponents = true,
     bool deferredComponentsEnabled = false,
   }) async {}