Make subcommands return success instead of null (#48100)

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

@@ -88,7 +88,6 @@ class AnalyzeCommand extends FlutterCommand {
         runner.getRepoRoots(),
         runner.getRepoPackages(),
       ).analyze();
-      return null;
     } else {
       await AnalyzeOnce(
         argResults,
@@ -96,7 +95,7 @@ class AnalyzeCommand extends FlutterCommand {
         runner.getRepoPackages(),
         workingDirectory: workingDirectory,
       ).analyze();
-      return null;
     }
+    return FlutterCommandResult.success();
   }
 }

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

@@ -200,7 +200,7 @@ class AssembleCommand extends FlutterCommand {
       final Depfile depfile = Depfile(result.inputFiles, result.outputFiles);
       depfile.writeToFile(globals.fs.file(depfileFile));
     }
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

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

@@ -178,7 +178,7 @@ class AttachCommand extends FlutterCommand {
         Artifacts: () => overrideArtifacts,
     });
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<void> _attachToDevice(Device device) async {

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

@@ -119,7 +119,7 @@ class BuildAarCommand extends BuildSubCommand {
       outputDirectoryPath: stringArg('output-dir'),
       buildNumber: buildNumber,
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 
   /// Returns the [FlutterProject] which is determined from the remaining command-line

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

@@ -89,6 +89,6 @@ class BuildAotCommand extends BuildSubCommand with TargetPlatformBasedDevelopmen
       extraGenSnapshotOptions: stringsArg(FlutterOptions.kExtraGenSnapshotOptions),
       dartDefines: dartDefines,
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -112,6 +112,6 @@ class BuildApkCommand extends BuildSubCommand {
       target: targetFile,
       androidBuildInfo: androidBuildInfo,
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -83,6 +83,6 @@ class BuildAppBundleCommand extends BuildSubCommand {
       target: targetFile,
       androidBuildInfo: androidBuildInfo,
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -139,6 +139,6 @@ class BuildBundleCommand extends BuildSubCommand {
       fileSystemScheme: stringArg('filesystem-scheme'),
       fileSystemRoots: stringsArg('filesystem-root'),
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -69,6 +69,6 @@ class BuildFuchsiaCommand extends BuildSubCommand {
       buildInfo: buildInfo,
       runnerPackageSource: stringArg('runner-source'),
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -92,6 +92,6 @@ class BuildIOSCommand extends BuildSubCommand {
       globals.printStatus('Built ${result.output}.');
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -204,8 +204,7 @@ class BuildIOSFrameworkCommand extends BuildSubCommand {
     }
 
     globals.printStatus('Frameworks written to ${outputDirectory.path}.');
-
-    return null;
+    return FlutterCommandResult.success();
   }
 
   /// Create podspec that will download and unzip remote engine assets so host apps can leverage CocoaPods

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

@@ -47,6 +47,6 @@ class BuildLinuxCommand extends BuildSubCommand {
       throwToolExit('"build linux" only supported on Linux hosts.');
     }
     await buildLinux(flutterProject.linux, buildInfo, target: targetFile);
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -51,6 +51,6 @@ class BuildMacosCommand extends BuildSubCommand {
       buildInfo: buildInfo,
       targetOverride: targetFile,
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -67,6 +67,6 @@ class BuildWebCommand extends BuildSubCommand {
       dartDefines,
       boolArg('csp')
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -47,6 +47,6 @@ class BuildWindowsCommand extends BuildSubCommand {
       throwToolExit('"build windows" only supported on Windows hosts.');
     }
     await buildWindows(flutterProject.windows, buildInfo, target: targetFile);
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -42,10 +42,10 @@ class ChannelCommand extends FlutterCommand {
           showAll: boolArg('all'),
           verbose: globalResults['verbose'] as bool,
         );
-        return null;
+        return FlutterCommandResult.success();
       case 1:
         await _switchChannel(argResults.rest[0]);
-        return null;
+        return FlutterCommandResult.success();
       default:
         throw ToolExit('Too many arguments.\n$usage');
     }

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

@@ -101,7 +101,7 @@ class ConfigCommand extends FlutterCommand {
   Future<FlutterCommandResult> runCommand() async {
     if (boolArg('machine')) {
       await handleMachine();
-      return null;
+      return FlutterCommandResult.success();
     }
 
     if (boolArg('clear-features')) {
@@ -110,7 +110,7 @@ class ConfigCommand extends FlutterCommand {
           globals.config.removeValue(feature.configSetting);
         }
       }
-      return null;
+      return FlutterCommandResult.success();
     }
 
     if (argResults.wasParsed('analytics')) {
@@ -157,7 +157,7 @@ class ConfigCommand extends FlutterCommand {
       globals.printStatus('\nYou may need to restart any open editors for them to read new settings.');
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<void> handleMachine() async {

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

@@ -297,7 +297,7 @@ class CreateCommand extends FlutterCommand {
       Cache.releaseLockEarly();
 
       await _writeSamplesJson(stringArg('list-samples'));
-      return null;
+      return FlutterCommandResult.success();
     }
 
     if (argResults.rest.isEmpty) {
@@ -482,8 +482,7 @@ To edit platform code in an IDE see https://flutter.dev/developing-packages/#edi
         globals.printStatus('Your $application code is in $relativeAppMain');
       }
     }
-
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<int> _generateModule(Directory directory, Map<String, dynamic> templateContext, { bool overwrite = false }) async {

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

@@ -74,7 +74,7 @@ class DaemonCommand extends FlutterCommand {
         Logger: () => notifyingLogger,
       },
     );
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

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

@@ -47,6 +47,6 @@ class DevicesCommand extends FlutterCommand {
       await Device.printDevices(devices);
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -185,7 +185,7 @@ class DriveCommand extends RunCommandBase {
       }
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   String _getTestFile() {

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

@@ -54,7 +54,7 @@ class EmulatorsCommand extends FlutterCommand {
       await _listEmulators(searchText);
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<void> _launchEmulator(String id) async {

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

@@ -76,6 +76,6 @@ class FormatCommand extends FlutterCommand {
       throwToolExit('Formatting failed: $result', exitCode: result);
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -31,7 +31,7 @@ class GenerateCommand extends FlutterCommand {
         globals.printError('Code generation failed.');
         break;
       }
-      if (codegenStatus ==CodegenStatus.Succeeded) {
+      if (codegenStatus == CodegenStatus.Succeeded) {
         break;
       }
     }
@@ -41,7 +41,7 @@ class GenerateCommand extends FlutterCommand {
       return dir.childDirectory('error_cache').existsSync();
     }, orElse: () => null);
     if (errorCacheParent == null) {
-      return null;
+      return FlutterCommandResult.success();
     }
     final Directory errorCache = errorCacheParent.childDirectory('error_cache');
     for (final File errorFile in errorCache.listSync(recursive: true).whereType<File>()) {
@@ -56,6 +56,6 @@ class GenerateCommand extends FlutterCommand {
         globals.printError('Error reading error in ${errorFile.path}');
       }
     }
-    return const FlutterCommandResult(ExitStatus.fail);
+    return FlutterCommandResult.fail();
   }
 }

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

@@ -219,7 +219,7 @@ class IdeConfigCommand extends FlutterCommand {
 
     if (boolArg('update-templates')) {
       _handleTemplateUpdate();
-      return null;
+      return FlutterCommandResult.success();
     }
 
     final String flutterRoot = globals.fs.path.absolute(Cache.flutterRoot);
@@ -243,7 +243,7 @@ class IdeConfigCommand extends FlutterCommand {
     globals.printStatus('Your IntelliJ configuration is now up to date. It is prudent to '
         'restart IntelliJ, if running.');
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   int _renderTemplate(String templateName, String dirPath, Map<String, dynamic> context) {

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

@@ -38,6 +38,6 @@ class InjectPluginsCommand extends FlutterCommand {
       globals.printStatus('This project does not use plugins, no GeneratedPluginRegistrants have been created.');
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -45,7 +45,7 @@ class InstallCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts
       throwToolExit('Install failed');
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

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

@@ -83,6 +83,6 @@ class LogsCommand extends FlutterCommand {
       throwToolExit('Error listening to $logReader logs.');
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -60,6 +60,6 @@ class MakeHostAppEditableCommand extends FlutterCommand {
       await _project.ios.makeHostAppEditable();
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -131,7 +131,7 @@ class PackagesGetCommand extends FlutterCommand {
       await exampleProject.ensureReadyForPlatformSpecificTooling(checkProjects: true);
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 
@@ -162,7 +162,7 @@ class PackagesTestCommand extends FlutterCommand {
   Future<FlutterCommandResult> runCommand() async {
     Cache.releaseLockEarly();
     await pub.batch(<String>['run', 'test', ...argResults.rest], context: PubContext.runTest, retry: false);
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 
@@ -203,7 +203,7 @@ class PackagesPublishCommand extends FlutterCommand {
     ];
     Cache.releaseLockEarly();
     await pub.interactively(<String>['publish', ...args]);
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 
@@ -234,7 +234,7 @@ class PackagesForwardCommand extends FlutterCommand {
   Future<FlutterCommandResult> runCommand() async {
     Cache.releaseLockEarly();
     await pub.interactively(<String>[_commandName, ...argResults.rest]);
-    return null;
+    return FlutterCommandResult.success();
   }
 
 }
@@ -262,6 +262,6 @@ class PackagesPassthroughCommand extends FlutterCommand {
   Future<FlutterCommandResult> runCommand() async {
     Cache.releaseLockEarly();
     await pub.interactively(argResults.rest);
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -88,6 +88,6 @@ class PrecacheCommand extends FlutterCommand {
     } else {
       globals.printStatus('Already up-to-date.');
     }
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -97,16 +97,16 @@ class ScreenshotCommand extends FlutterCommand {
     switch (stringArg(_kType)) {
       case _kDeviceType:
         await runScreenshot(outputFile);
-        return null;
+        return FlutterCommandResult.success();
       case _kSkiaType:
         await runSkia(outputFile);
-        return null;
+        return FlutterCommandResult.success();
       case _kRasterizerType:
         await runRasterizer(outputFile);
-        return null;
+        return FlutterCommandResult.success();
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<void> runScreenshot(File outputFile) async {

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

@@ -50,7 +50,7 @@ class ShellCompletionCommand extends FlutterCommand {
 
     if (argResults.rest.isEmpty || argResults.rest.first == '-') {
       stdout.write(generateCompletionScript(<String>['flutter']));
-      return null;
+      return FlutterCommandResult.warning();
     }
 
     final File outputFile = globals.fs.file(argResults.rest.first);
@@ -67,6 +67,6 @@ class ShellCompletionCommand extends FlutterCommand {
       throwToolExit('Unable to write shell completion setup script.\n$error', exitCode: 1);
     }
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -270,7 +270,7 @@ class TestCommand extends FastFlutterCommand {
     if (result != 0) {
       throwToolExit(null);
     }
-    return const FlutterCommandResult(ExitStatus.success);
+    return FlutterCommandResult.success();
   }
 
   Future<void> _buildTestAsset() async {

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

@@ -22,6 +22,6 @@ class TrainingCommand extends FlutterCommand {
   @override
   Future<FlutterCommandResult> runCommand() async {
     // This command does not do anything yet :).
-    return null;
+    return FlutterCommandResult.success();
   }
 }

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

@@ -93,7 +93,7 @@ class UnpackCommand extends FlutterCommand {
     if (!success) {
       throwToolExit('Failed to unpack desktop artifacts.');
     }
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

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

@@ -180,7 +180,7 @@ class UpdatePackagesCommand extends FlutterCommand {
         );
       }
       globals.printStatus('All pubspecs were up to date.');
-      return null;
+      return FlutterCommandResult.success();
     }
 
     if (upgrade || isPrintPaths || isPrintTransitiveClosure) {
@@ -289,12 +289,12 @@ class UpdatePackagesCommand extends FlutterCommand {
         tree._dependencyTree.forEach((String from, Set<String> to) {
           globals.printStatus('$from -> $to');
         });
-        return null;
+        return FlutterCommandResult.success();
       }
 
       if (isPrintPaths) {
         showDependencyPaths(from: stringArg('from'), to: stringArg('to'), tree: tree);
-        return null;
+        return FlutterCommandResult.success();
       }
 
       // Now that we have collected all the data, we can apply our dependency
@@ -328,7 +328,7 @@ class UpdatePackagesCommand extends FlutterCommand {
     final double seconds = timer.elapsedMilliseconds / 1000.0;
     globals.printStatus('\nRan \'pub\' $count time${count == 1 ? "" : "s"} and fetched coverage data in ${seconds.toStringAsFixed(1)}s.');
 
-    return null;
+    return FlutterCommandResult.success();
   }
 
   void showDependencyPaths({

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

@@ -50,14 +50,13 @@ class UpgradeCommand extends FlutterCommand {
   bool get shouldUpdateCache => false;
 
   @override
-  Future<FlutterCommandResult> runCommand() async {
-    await _commandRunner.runCommand(
+  Future<FlutterCommandResult> runCommand() {
+    return _commandRunner.runCommand(
       boolArg('force'),
       boolArg('continue'),
       GitTagVersion.determine(),
       FlutterVersion.instance,
     );
-    return null;
   }
 }
 
@@ -74,7 +73,7 @@ class UpgradeCommandRunner {
     } else {
       await runCommandSecondHalf(flutterVersion);
     }
-    return null;
+    return FlutterCommandResult.success();
   }
 
   Future<void> runCommandFirstHalf(

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

@@ -143,6 +143,6 @@ class VersionCommand extends FlutterCommand {
       throwToolExit(null, exitCode: code);
     }
 
-    return const FlutterCommandResult(ExitStatus.success);
+    return FlutterCommandResult.success();
   }
 }

packages/flutter_tools/lib/src/reporting/events.dart

@@ -171,7 +171,9 @@ class BuildEvent extends UsageEvent {
 /// An event that reports the result of a top-level command.
 class CommandResultEvent extends UsageEvent {
   CommandResultEvent(String commandPath, FlutterCommandResult result)
-      : super(commandPath, result?.toString() ?? 'unspecified');
+      : assert(commandPath != null),
+        assert(result != null),
+        super(commandPath, result.toString());
 
   @override
   void send() {

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -50,6 +50,21 @@ class FlutterCommandResult {
     this.endTimeOverride,
   });
 
+  /// A command that succeeded. It is used to log the result of a command invocation.
+  factory FlutterCommandResult.success() {
+    return const FlutterCommandResult(ExitStatus.success);
+  }
+
+  /// A command that exited with a warning. It is used to log the result of a command invocation.
+  factory FlutterCommandResult.warning() {
+    return const FlutterCommandResult(ExitStatus.warning);
+  }
+
+  /// A command that failed. It is used to log the result of a command invocation.
+  factory FlutterCommandResult.fail() {
+    return const FlutterCommandResult(ExitStatus.fail);
+  }
+
   final ExitStatus exitStatus;
 
   /// Optional data that can be appended to the timing event.
@@ -516,12 +531,9 @@ abstract class FlutterCommand extends Command<void> {
         flutterUsage.printWelcome();
         final String commandPath = await usagePath;
         _registerSignalHandlers(commandPath, startTime);
-        FlutterCommandResult commandResult;
+        FlutterCommandResult commandResult = FlutterCommandResult.fail();
         try {
           commandResult = await verifyThenRunCommand(commandPath);
-        } on ToolExit {
-          commandResult = const FlutterCommandResult(ExitStatus.fail);
-          rethrow;
         } finally {
           final DateTime endTime = systemClock.now();
           globals.printTrace(userMessages.flutterElapsedTime(name, getElapsedAsMilliseconds(endTime.difference(startTime))));
@@ -557,15 +569,15 @@ abstract class FlutterCommand extends Command<void> {
     if (commandPath == null) {
       return;
     }
-
+    assert(commandResult != null);
     // Send command result.
     CommandResultEvent(commandPath, commandResult).send();
 
     // Send timing.
     final List<String> labels = <String>[
-      if (commandResult?.exitStatus != null)
+      if (commandResult.exitStatus != null)
         getEnumName(commandResult.exitStatus),
-      if (commandResult?.timingLabelParts?.isNotEmpty ?? false)
+      if (commandResult.timingLabelParts?.isNotEmpty ?? false)
         ...commandResult.timingLabelParts,
     ];
 
@@ -577,7 +589,7 @@ abstract class FlutterCommand extends Command<void> {
       name,
       // If the command provides its own end time, use it. Otherwise report
       // the duration of the entire execution.
-      (commandResult?.endTimeOverride ?? endTime).difference(startTime),
+      (commandResult.endTimeOverride ?? endTime).difference(startTime),
       // Report in the form of `success-[parameter1-parameter2]`, all of which
       // can be null if the command doesn't provide a FlutterCommandResult.
       label: label == '' ? null : label,

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

@@ -75,7 +75,7 @@ void main() {
         const GitTagVersion.unknown(),
         flutterVersion,
       );
-      expect(await result, null);
+      expect(await result, FlutterCommandResult.success());
     }, overrides: <Type, Generator>{
       ProcessManager: () => processManager,
       Platform: () => fakePlatform,
@@ -103,7 +103,7 @@ void main() {
         gitTagVersion,
         flutterVersion,
       );
-      expect(await result, null);
+      expect(await result, FlutterCommandResult.success());
     }, overrides: <Type, Generator>{
       ProcessManager: () => processManager,
       Platform: () => fakePlatform,
@@ -116,7 +116,7 @@ void main() {
         gitTagVersion,
         flutterVersion,
       );
-      expect(await result, null);
+      expect(await result, FlutterCommandResult.success());
     }, overrides: <Type, Generator>{
       ProcessManager: () => processManager,
       Platform: () => fakePlatform,
@@ -130,7 +130,7 @@ void main() {
         gitTagVersion,
         flutterVersion,
       );
-      expect(await result, null);
+      expect(await result, FlutterCommandResult.success());
       verifyNever(globals.processManager.start(
         <String>[
           globals.fs.path.join('bin', 'flutter'),

packages/flutter_tools/test/general.shard/commands/build_aar_test.dart

@@ -24,10 +24,12 @@ import '../../src/mocks.dart';
 void main() {
   Cache.disableLocking();
 
-  group('getUsage', () {
+  group('Usage', () {
     Directory tempDir;
+    Usage mockUsage;
 
     setUp(() {
+      mockUsage = MockUsage();
       tempDir = globals.fs.systemTempDirectory.createTempSync('flutter_tools_packages_test.');
     });
 
@@ -83,6 +85,26 @@ void main() {
     }, overrides: <Type, Generator>{
       AndroidBuilder: () => FakeAndroidBuilder(),
     });
+
+    testUsingContext('logs success', () async {
+      final String projectPath = await createProject(tempDir,
+          arguments: <String>['--no-pub', '--template=module']);
+
+      await runCommandIn(projectPath,
+          arguments: <String>['--target-platform=android-arm']);
+
+      verify(mockUsage.sendEvent(
+        'tool-command-result',
+        'aar',
+        label: 'success',
+        value: anyNamed('value'),
+        parameters: anyNamed('parameters'),
+      )).called(1);
+    },
+    overrides: <Type, Generator>{
+      AndroidBuilder: () => FakeAndroidBuilder(),
+      Usage: () => mockUsage,
+    });
   });
 
   group('Gradle', () {

packages/flutter_tools/test/general.shard/commands/build_apk_test.dart

@@ -26,10 +26,12 @@ import '../../src/mocks.dart';
 void main() {
   Cache.disableLocking();
 
-  group('getUsage', () {
+  group('Usage', () {
     Directory tempDir;
+    Usage mockUsage;
 
     setUp(() {
+      mockUsage = MockUsage();
       tempDir = globals.fs.systemTempDirectory.createTempSync('flutter_tools_packages_test.');
     });
 
@@ -92,6 +94,25 @@ void main() {
     }, overrides: <Type, Generator>{
       AndroidBuilder: () => FakeAndroidBuilder(),
     });
+
+    testUsingContext('logs success', () async {
+      final String projectPath = await createProject(tempDir,
+          arguments: <String>['--no-pub', '--template=app']);
+
+      await runBuildApkCommand(projectPath);
+
+      verify(mockUsage.sendEvent(
+        'tool-command-result',
+        'apk',
+        label: 'success',
+        value: anyNamed('value'),
+        parameters: anyNamed('parameters'),
+      )).called(1);
+    },
+    overrides: <Type, Generator>{
+      AndroidBuilder: () => FakeAndroidBuilder(),
+      Usage: () => mockUsage,
+    });
   });
 
   group('Gradle', () {

packages/flutter_tools/test/general.shard/commands/build_appbundle_test.dart

@@ -26,11 +26,13 @@ import '../../src/mocks.dart';
 void main() {
   Cache.disableLocking();
 
-  group('getUsage', () {
+  group('Usage', () {
     Directory tempDir;
+    Usage mockUsage;
 
     setUp(() {
       tempDir = globals.fs.systemTempDirectory.createTempSync('flutter_tools_packages_test.');
+      mockUsage = MockUsage();
     });
 
     tearDown(() {
@@ -75,6 +77,25 @@ void main() {
     }, overrides: <Type, Generator>{
       AndroidBuilder: () => FakeAndroidBuilder(),
     });
+
+    testUsingContext('logs success', () async {
+      final String projectPath = await createProject(tempDir,
+          arguments: <String>['--no-pub', '--template=app']);
+
+      await runBuildAppBundleCommand(projectPath);
+
+      verify(mockUsage.sendEvent(
+        'tool-command-result',
+        'appbundle',
+        label: 'success',
+        value: anyNamed('value'),
+        parameters: anyNamed('parameters'),
+      )).called(1);
+    },
+    overrides: <Type, Generator>{
+      AndroidBuilder: () => FakeAndroidBuilder(),
+      Usage: () => mockUsage,
+    });
   });
 
   group('Gradle', () {

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

@@ -342,7 +342,7 @@ class _CrashCommand extends FlutterCommand {
 
     fn3();
 
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

packages/flutter_tools/test/general.shard/runner/flutter_command_test.dart

@@ -217,6 +217,14 @@ void main() {
       }
     });
 
+    test('FlutterCommandResult.success()', () async {
+      expect(FlutterCommandResult.success().exitStatus, ExitStatus.success);
+    });
+
+    test('FlutterCommandResult.warning()', () async {
+      expect(FlutterCommandResult.warning().exitStatus, ExitStatus.warning);
+    });
+
     group('signals tests', () {
       MockIoProcessSignal mockSignal;
       ProcessSignal signalUnderTest;
@@ -297,7 +305,7 @@ void main() {
           'flutter',
           'dummy',
           const Duration(milliseconds: 1000),
-          null,
+          'fail',
         ],
       );
     });
@@ -388,7 +396,7 @@ class FakeCommand extends FlutterCommand {
 
   @override
   Future<FlutterCommandResult> runCommand() async {
-    return null;
+    return FlutterCommandResult.success();
   }
 }
 

packages/flutter_tools/test/general.shard/runner/utils.dart

@@ -36,7 +36,7 @@ class DummyFlutterCommand extends FlutterCommand {
 
   @override
   Future<FlutterCommandResult> runCommand() async {
-    return commandFunction == null ? null : await commandFunction();
+    return commandFunction == null ? FlutterCommandResult.fail() : await commandFunction();
   }
 }