Add --empty to the flutter create command (#113873)

Author: gspencergoog

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

@@ -65,6 +65,12 @@ class CreateCommand extends CreateBase {
         'https://api.flutter.dev/flutter/widgets/SingleChildScrollView-class.html',
       valueHelp: 'id',
     );
+    argParser.addFlag(
+      'empty',
+      abbr: 'e',
+      help: 'Specifies creating using an application template with a main.dart that is minimal, '
+        'including no comments, as a starting point for a new application. Implies "--template=app".',
+    );
     argParser.addOption(
       'list-samples',
       help: 'Specifies a JSON output file for a listing of Flutter code samples '
@@ -191,9 +197,17 @@ class CreateCommand extends CreateBase {
       return FlutterCommandResult.success();
     }
 
+    if (argResults!.wasParsed('empty') && argResults!.wasParsed('sample')) {
+      throwToolExit(
+        'Only one of --empty or --sample may be specified, not both.',
+        exitCode: 2,
+      );
+    }
+
     validateOutputDirectoryArg();
     String? sampleCode;
     final String? sampleArgument = stringArg('sample');
+    final bool emptyArgument = boolArg('empty') ?? false;
     if (sampleArgument != null) {
       final String? templateArgument = stringArg('template');
       if (templateArgument != null && stringToProjectType(templateArgument) != FlutterProjectType.app) {
@@ -299,6 +313,7 @@ class CreateCommand extends CreateBase {
       flutterRoot: flutterRoot,
       withPlatformChannelPluginHook: generateMethodChannelsPlugin,
       withFfiPluginHook: generateFfiPlugin,
+      withEmptyMain: emptyArgument,
       androidLanguage: stringArgDeprecated('android-language'),
       iosLanguage: stringArgDeprecated('ios-language'),
       iosDevelopmentTeam: developmentTeam,
@@ -411,11 +426,15 @@ class CreateCommand extends CreateBase {
       );
     }
     if (sampleCode != null) {
-      generatedFileCount += _applySample(relativeDir, sampleCode);
+      _applySample(relativeDir, sampleCode);
+    }
+    if (sampleCode != null || emptyArgument) {
+      generatedFileCount += _removeTestDir(relativeDir);
     }
     globals.printStatus('Wrote $generatedFileCount files.');
     globals.printStatus('\nAll done!');
-    final String application = sampleCode != null ? 'sample application' : 'application';
+    final String application =
+      '${emptyArgument ? 'empty' : ''}${sampleCode != null ? 'sample' : ''} application';
     if (generatePackage) {
       final String relativeMainPath = globals.fs.path.normalize(globals.fs.path.join(
         relativeDirPath,
@@ -657,10 +676,13 @@ Your $application code is in $relativeAppMain.
   // documentation website in sampleCode. Returns the difference in the number
   // of files after applying the sample, since it also deletes the application's
   // test directory (since the template's test doesn't apply to the sample).
-  int _applySample(Directory directory, String sampleCode) {
+  void _applySample(Directory directory, String sampleCode) {
     final File mainDartFile = directory.childDirectory('lib').childFile('main.dart');
     mainDartFile.createSync(recursive: true);
     mainDartFile.writeAsStringSync(sampleCode);
+  }
+
+  int _removeTestDir(Directory directory) {
     final Directory testDir = directory.childDirectory('test');
     final List<FileSystemEntity> files = testDir.listSync(recursive: true);
     testDir.deleteSync(recursive: true);

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

@@ -354,6 +354,7 @@ abstract class CreateBase extends FlutterCommand {
     String? gradleVersion,
     bool withPlatformChannelPluginHook = false,
     bool withFfiPluginHook = false,
+    bool withEmptyMain = false,
     bool ios = false,
     bool android = false,
     bool web = false,
@@ -409,6 +410,7 @@ abstract class CreateBase extends FlutterCommand {
       'withFfiPluginHook': withFfiPluginHook,
       'withPlatformChannelPluginHook': withPlatformChannelPluginHook,
       'withPluginHook': withFfiPluginHook || withPlatformChannelPluginHook,
+      'withEmptyMain': withEmptyMain,
       'androidLanguage': androidLanguage,
       'iosLanguage': iosLanguage,
       'hasIosDevelopmentTeam': iosDevelopmentTeam != null && iosDevelopmentTeam.isNotEmpty,

packages/flutter_tools/templates/app/README.md.tmpl

@@ -1,6 +1,7 @@
 # {{projectName}}
 
 {{description}}
+{{^withEmptyMain}}
 
 ## Getting Started
 
@@ -14,3 +15,4 @@ A few resources to get you started if this is your first Flutter project:
 For help getting started with Flutter development, view the
 [online documentation](https://docs.flutter.dev/), which offers tutorials,
 samples, guidance on mobile development, and a full API reference.
+{{/withEmptyMain}}

packages/flutter_tools/templates/app/lib/main.dart.tmpl

@@ -1,4 +1,26 @@
 import 'package:flutter/material.dart';
+{{#withEmptyMain}}
+
+void main() {
+  runApp(const MainApp());
+}
+
+class MainApp extends StatelessWidget {
+  const MainApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const MaterialApp(
+      home: Scaffold(
+        body: Center(
+          child: Text('Hello World!'),
+        ),
+      ),
+    );
+  }
+}
+{{/withEmptyMain}}
+{{^withEmptyMain}}
 {{#withPlatformChannelPluginHook}}
 import 'dart:async';
 
@@ -248,3 +270,4 @@ class _MyAppState extends State<MyApp> {
   }
 }
 {{/withFfiPluginHook}}
+{{/withEmptyMain}}

packages/flutter_tools/templates/app/pubspec.yaml.tmpl

@@ -1,6 +1,25 @@
 name: {{projectName}}
 description: {{description}}
+{{#withEmptyMain}}
+publish_to: 'none'
+version: 0.1.0
 
+environment:
+  sdk: {{dartSdkVersionBounds}}
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  flutter_lints: ^2.0.0
+
+flutter:
+  uses-material-design: true
+{{/withEmptyMain}}
+{{^withEmptyMain}}
 # The following line prevents the package from being accidentally published to
 # pub.dev using `flutter pub publish`. This is preferred for private packages.
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
@@ -100,3 +119,4 @@ flutter:
   #
   # For details regarding fonts from package dependencies,
   # see https://flutter.dev/custom-fonts/#from-packages
+{{/withEmptyMain}}

packages/flutter_tools/templates/app_shared/analysis_options.yaml.tmpl

@@ -1,3 +1,4 @@
+{{^withEmptyMain}}
 # This file configures the analyzer, which statically analyzes Dart code to
 # check for errors, warnings, and lints.
 #
@@ -7,7 +8,9 @@
 
 # The following line activates a set of recommended lints for Flutter apps,
 # packages, and plugins designed to encourage good coding practices.
+{{/withEmptyMain}}
 include: package:flutter_lints/flutter.yaml
+{{^withEmptyMain}}
 
 linter:
   # The lint rules applied to this project can be customized in the
@@ -27,3 +30,4 @@ linter:
 
 # Additional information about this file can be found at
 # https://dart.dev/guides/language/analysis-options
+{{/withEmptyMain}}

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

@@ -1944,6 +1944,28 @@ void main() {
     },
   );
 
+  testUsingContext('can create an empty application project', () async {
+    await _createAndAnalyzeProject(
+      projectDir,
+      <String>['--no-pub', '--empty'],
+      <String>[
+        'lib/main.dart',
+        'flutter_project.iml',
+        'android/app/src/main/AndroidManifest.xml',
+        'ios/Flutter/AppFrameworkInfo.plist',
+      ],
+      unexpectedPaths: <String>['test'],
+    );
+    expect(projectDir.childDirectory('lib').childFile('main.dart').readAsStringSync(),
+      contains("Text('Hello World!')"));
+    expect(projectDir.childDirectory('lib').childFile('main.dart').readAsStringSync(),
+      isNot(contains('int _counter')));
+    expect(projectDir.childFile('analysis_options.yaml').readAsStringSync(),
+      isNot(contains('#')));
+    expect(projectDir.childFile('README.md').readAsStringSync(),
+      isNot(contains('Getting Started')));
+  });
+
   testUsingContext('can create a sample-based project', () async {
     await _createAndAnalyzeProject(
       projectDir,