<Null> -> <void>

script/tool/lib/src/analyze_command.dart

@@ -31,7 +31,7 @@ class AnalyzeCommand extends PluginCommand {
       'This command requires "pub" and "flutter" to be in your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
 
     print('Verifying analysis settings...');

script/tool/lib/src/build_examples_command.dart

@@ -39,7 +39,7 @@ class BuildExamplesCommand extends PluginCommand {
       'This command requires "flutter" to be in your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     final List<String> platformSwitches = <String>[
       kApk,
       kIpa,

script/tool/lib/src/common.dart

@@ -161,7 +161,7 @@ class ToolExit extends Error {
   final int exitCode;
 }
 
-abstract class PluginCommand extends Command<Null> {
+abstract class PluginCommand extends Command<void> {
   PluginCommand(
     this.packagesDir,
     this.fileSystem, {

script/tool/lib/src/create_all_plugins_app_command.dart

@@ -36,7 +36,7 @@ class CreateAllPluginsAppCommand extends PluginCommand {
   String get name => 'all-plugins-app';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     final int exitCode = await _createApp();
     if (exitCode != 0) {
       throw ToolExit(exitCode);

script/tool/lib/src/drive_examples_command.dart

@@ -48,7 +48,7 @@ class DriveExamplesCommand extends PluginCommand {
       'integration_test/*_test.dart.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final List<String> failingTests = <String>[];
     final bool isLinux = argResults[kLinux] == true;

script/tool/lib/src/firebase_test_lab_command.dart

@@ -93,7 +93,7 @@ class FirebaseTestLabCommand extends PluginCommand {
   }
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final Stream<Directory> packagesWithTests = getPackages().where(
         (Directory d) =>

script/tool/lib/src/format_command.dart

@@ -38,7 +38,7 @@ class FormatCommand extends PluginCommand {
       'your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final String googleFormatterPath = await _getGoogleFormatterPath();
 
@@ -82,7 +82,7 @@ class FormatCommand extends PluginCommand {
     return true;
   }
 
-  Future<Null> _formatCppAndObjectiveC() async {
+  Future<void> _formatCppAndObjectiveC() async {
     print('Formatting all .cc, .cpp, .mm, .m, and .h files...');
     final Iterable<String> allFiles = <String>[]
       ..addAll(await _getFilesWithExtension('.h'))
@@ -100,15 +100,15 @@ class FormatCommand extends PluginCommand {
     }
   }
 
-  Future<Null> _formatJava(String googleFormatterPath) async {
+  Future<void> _formatJava(String googleFormatterPath) async {
     print('Formatting all .java files...');
     final Iterable<String> javaFiles = await _getFilesWithExtension('.java');
     await processRunner.runAndStream('java',
         <String>['-jar', googleFormatterPath, '--replace']..addAll(javaFiles),
         workingDir: packagesDir, exitOnError: true);
   }
 
-  Future<Null> _formatDart() async {
+  Future<void> _formatDart() async {
     // This actually should be fine for non-Flutter Dart projects, no need to
     // specifically shell out to dartfmt -w in that case.
     print('Formatting all .dart files...');

script/tool/lib/src/java_test_command.dart

@@ -27,7 +27,7 @@ class JavaTestCommand extends PluginCommand {
   static const String _gradleWrapper = 'gradlew';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final Stream<Directory> examplesWithTests = getExamples().where(
         (Directory d) =>

script/tool/lib/src/license_check_command.dart

@@ -110,7 +110,7 @@ class LicenseCheckCommand extends PluginCommand {
       'Ensures that all code files have copyright/license blocks.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     final Iterable<File> codeFiles = (await _getAllFiles()).where((File file) =>
         _codeFileExtensions.contains(p.extension(file.path)) &&
         !_shouldIgnoreFile(file));

script/tool/lib/src/lint_podspecs_command.dart

@@ -52,7 +52,7 @@ class LintPodspecsCommand extends PluginCommand {
   final Print _print;
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     if (!platform.isMacOS) {
       _print('Detected platform is not macOS, skipping podspec lint');
       return;

script/tool/lib/src/list_command.dart

@@ -32,7 +32,7 @@ class ListCommand extends PluginCommand {
   final String description = 'Lists packages or files';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     switch (argResults[_type] as String) {
       case _plugin:

script/tool/lib/src/main.dart

@@ -41,7 +41,7 @@ void main(List<String> args) {
     }
   }
 
-  final CommandRunner<Null> commandRunner = CommandRunner<Null>(
+  final CommandRunner<void> commandRunner = CommandRunner<void>(
       'pub global run flutter_plugin_tools',
       'Productivity utils for hosting multiple plugins within one repository.')
     ..addCommand(AnalyzeCommand(packagesDir, fileSystem))

script/tool/lib/src/publish_check_command.dart

@@ -26,7 +26,7 @@ class PublishCheckCommand extends PluginCommand {
       'Checks to make sure that a plugin *could* be published.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final List<Directory> failedPackages = <Directory>[];
 

script/tool/lib/src/publish_plugin_command.dart

@@ -89,7 +89,7 @@ class PublishPluginCommand extends PluginCommand {
   StreamSubscription<String> _stdinSubscription;
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     _print('Checking local repo...');
     _packageDir = _checkPackageDir();

script/tool/lib/src/test_command.dart

@@ -30,7 +30,7 @@ class TestCommand extends PluginCommand {
       'This command requires "flutter" to be in your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final List<String> failingPackages = <String>[];
     await for (Directory packageDir in getPackages()) {

script/tool/lib/src/version_check_command.dart

@@ -113,7 +113,7 @@ class VersionCheckCommand extends PluginCommand {
       'This command requires "pub" and "flutter" to be in your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     checkSharding();
     final GitVersionFinder gitVersionFinder = await retrieveVersionFinder();
 

script/tool/lib/src/xctest_command.dart

@@ -46,7 +46,7 @@ class XCTestCommand extends PluginCommand {
       'This command requires "flutter" and "xcrun" to be in your path.';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     String destination = argResults[_kiOSDestination] as String;
     if (destination == null) {
       String simulatorId = await _findAvailableIphoneSimulator();

script/tool/test/analyze_command_test.dart

@@ -22,7 +22,7 @@ void main() {
         mockPackagesDir, mockFileSystem,
         processRunner: processRunner);
 
-    runner = CommandRunner<Null>('analyze_command', 'Test for analyze_command');
+    runner = CommandRunner<void>('analyze_command', 'Test for analyze_command');
     runner.addCommand(analyzeCommand);
   });
 

script/tool/test/build_examples_command_test.dart

@@ -13,7 +13,7 @@ import 'util.dart';
 
 void main() {
   group('test build_example_command', () {
-    CommandRunner<Null> runner;
+    CommandRunner<void> runner;
     RecordingProcessRunner processRunner;
     final String flutterCommand =
         LocalPlatform().isWindows ? 'flutter.bat' : 'flutter';
@@ -25,7 +25,7 @@ void main() {
           mockPackagesDir, mockFileSystem,
           processRunner: processRunner);
 
-      runner = CommandRunner<Null>(
+      runner = CommandRunner<void>(
           'build_examples_command', 'Test for build_example_command');
       runner.addCommand(command);
       cleanupPackages();

script/tool/test/common_test.dart

@@ -44,7 +44,7 @@ void main() {
       gitDir: gitDir,
     );
     runner =
-        CommandRunner<Null>('common_command', 'Test for common functionality');
+        CommandRunner<void>('common_command', 'Test for common functionality');
     runner.addCommand(samplePluginCommand);
   });
 
@@ -320,7 +320,7 @@ class SamplePluginCommand extends PluginCommand {
   final String description = 'sample command';
 
   @override
-  Future<Null> run() async {
+  Future<void> run() async {
     await for (Directory package in getPlugins()) {
       this.plugins_.add(package.path);
     }

script/tool/test/create_all_plugins_app_command_test.dart

@@ -12,7 +12,7 @@ import 'util.dart';
 
 void main() {
   group('$CreateAllPluginsAppCommand', () {
-    CommandRunner<Null> runner;
+    CommandRunner<void> runner;
     FileSystem fileSystem;
     Directory testRoot;
     Directory packagesDir;
@@ -32,7 +32,7 @@ void main() {
         pluginsRoot: testRoot,
       );
       appDir = command.appDirectory;
-      runner = CommandRunner<Null>(
+      runner = CommandRunner<void>(
           'create_all_test', 'Test for $CreateAllPluginsAppCommand');
       runner.addCommand(command);
     });

script/tool/test/drive_examples_command_test.dart

@@ -14,7 +14,7 @@ import 'util.dart';
 
 void main() {
   group('test drive_example_command', () {
-    CommandRunner<Null> runner;
+    CommandRunner<void> runner;
     RecordingProcessRunner processRunner;
     final String flutterCommand =
         LocalPlatform().isWindows ? 'flutter.bat' : 'flutter';
@@ -25,7 +25,7 @@ void main() {
           mockPackagesDir, mockFileSystem,
           processRunner: processRunner);
 
-      runner = CommandRunner<Null>(
+      runner = CommandRunner<void>(
           'drive_examples_command', 'Test for drive_example_command');
       runner.addCommand(command);
     });

script/tool/test/firebase_test_lab_test.dart

@@ -15,7 +15,7 @@ import 'util.dart';
 void main() {
   group('$FirebaseTestLabCommand', () {
     final List<String> printedMessages = <String>[];
-    CommandRunner<FirebaseTestLabCommand> runner;
+    CommandRunner<void> runner;
     RecordingProcessRunner processRunner;
 
     setUp(() {
@@ -26,7 +26,7 @@ void main() {
           processRunner: processRunner,
           print: (Object message) => printedMessages.add(message.toString()));
 
-      runner = CommandRunner<Null>(
+      runner = CommandRunner<void>(
           'firebase_test_lab_command', 'Test for $FirebaseTestLabCommand');
       runner.addCommand(command);
     });

script/tool/test/java_test_command_test.dart

@@ -12,7 +12,7 @@ import 'util.dart';
 
 void main() {
   group('$JavaTestCommand', () {
-    CommandRunner<JavaTestCommand> runner;
+    CommandRunner<void> runner;
     final RecordingProcessRunner processRunner = RecordingProcessRunner();
 
     setUp(() {
@@ -22,7 +22,7 @@ void main() {
           processRunner: processRunner);
 
       runner =
-          CommandRunner<Null>('java_test_test', 'Test for $JavaTestCommand');
+          CommandRunner<void>('java_test_test', 'Test for $JavaTestCommand');
       runner.addCommand(command);
     });
 

script/tool/test/license_check_command_test.dart

@@ -11,7 +11,7 @@ import 'package:test/test.dart';
 
 void main() {
   group('$LicenseCheckCommand', () {
-    CommandRunner<Null> runner;
+    CommandRunner<void> runner;
     FileSystem fileSystem;
     List<String> printedMessages;
     Directory root;
@@ -29,7 +29,7 @@ void main() {
         print: (Object message) => printedMessages.add(message.toString()),
       );
       runner =
-          CommandRunner<Null>('license_test', 'Test for $LicenseCheckCommand');
+          CommandRunner<void>('license_test', 'Test for $LicenseCheckCommand');
       runner.addCommand(command);
     });
 
@@ -304,18 +304,20 @@ void main() {
       _writeLicense(
         bad,
         copyright: 'Copyright 2017 Some New Authors.',
-          license: <String>[
-            'Licensed under the Apache License, Version 2.0 (the "License");',
-            'you may not use this file except in compliance with the License.'
-          ],
+        license: <String>[
+          'Licensed under the Apache License, Version 2.0 (the "License");',
+          'you may not use this file except in compliance with the License.'
+        ],
       );
 
       await expectLater(() => runner.run(<String>['license-check']),
           throwsA(const TypeMatcher<ToolExit>()));
 
       // Failure should give information about the problematic files.
-      expect(printedMessages,
-          contains('No recognized license was found for the following third-party files:'));
+      expect(
+          printedMessages,
+          contains(
+              'No recognized license was found for the following third-party files:'));
       expect(printedMessages, contains('  third_party/bad.cc'));
       // Failure shouldn't print the success message.
       expect(printedMessages,

script/tool/test/lint_podspecs_command_test.dart

@@ -17,7 +17,7 @@ import 'util.dart';
 
 void main() {
   group('$LintPodspecsCommand', () {
-    CommandRunner<Null> runner;
+    CommandRunner<void> runner;
     MockPlatform mockPlatform;
     final RecordingProcessRunner processRunner = RecordingProcessRunner();
     List<String> printedMessages;
@@ -37,7 +37,7 @@ void main() {
       );
 
       runner =
-          CommandRunner<Null>('podspec_test', 'Test for $LintPodspecsCommand');
+          CommandRunner<void>('podspec_test', 'Test for $LintPodspecsCommand');
       runner.addCommand(command);
       final MockProcess mockLintProcess = MockProcess();
       mockLintProcess.exitCodeCompleter.complete(0);
@@ -103,8 +103,7 @@ void main() {
         ]),
       );
 
-      expect(
-          printedMessages, contains('Linting plugin1.podspec'));
+      expect(printedMessages, contains('Linting plugin1.podspec'));
       expect(printedMessages, contains('Foo'));
       expect(printedMessages, contains('Bar'));
     });
@@ -166,8 +165,7 @@ void main() {
         ]),
       );
 
-      expect(
-          printedMessages, contains('Linting plugin1.podspec'));
+      expect(printedMessages, contains('Linting plugin1.podspec'));
     });
   });
 }

script/tool/test/list_command_test.dart

@@ -11,13 +11,13 @@ import 'util.dart';
 
 void main() {
   group('$ListCommand', () {
-    CommandRunner<ListCommand> runner;
+    CommandRunner<void> runner;
 
     setUp(() {
       initializeFakePackages();
       final ListCommand command = ListCommand(mockPackagesDir, mockFileSystem);
 
-      runner = CommandRunner<Null>('list_test', 'Test for $ListCommand');
+      runner = CommandRunner<void>('list_test', 'Test for $ListCommand');
       runner.addCommand(command);
     });