Add the --platform and --empty arguments to the flutter create tool (#144)

Author: gspencergoog

pkgs/dart_mcp_server/lib/src/mixins/dash_cli.dart

@@ -102,6 +102,29 @@ base mixin DashCliSupport on ToolsSupport, LoggingSupport, RootsTrackingSupport
         ),
       );
     }
+    final platforms =
+        ((args[ParameterNames.platform] as List?)?.cast<String>() ?? [])
+            .toSet();
+    if (projectType == 'flutter') {
+      // Platforms are ignored for Dart, so no need to validate them.
+      final invalidPlatforms = platforms.difference(_allowedFlutterPlatforms);
+      if (invalidPlatforms.isNotEmpty) {
+        final plural =
+            invalidPlatforms.length > 1
+                ? 'are not valid platforms'
+                : 'is not a valid platform';
+        errors.add(
+          ValidationError(
+            ValidationErrorType.itemInvalid,
+            path: [ParameterNames.platform],
+            details:
+                '${invalidPlatforms.join(',')} $plural. Platforms '
+                '${_allowedFlutterPlatforms.map((e) => '`$e`').join(', ')} '
+                'are the only allowed values for the platform list argument.',
+          ),
+        );
+      }
+    }
 
     if (errors.isNotEmpty) {
       return CallToolResult(
@@ -117,6 +140,13 @@ base mixin DashCliSupport on ToolsSupport, LoggingSupport, RootsTrackingSupport
     final commandArgs = [
       'create',
       if (template != null && template.isNotEmpty) ...['--template', template],
+      if (projectType == 'flutter' && platforms.isNotEmpty)
+        '--platform=${platforms.join(',')}',
+      // Create an "empty" project by default so the LLM doesn't have to deal
+      // with all the boilerplate and comments.
+      if (projectType == 'flutter' &&
+          (args[ParameterNames.empty] as bool? ?? true))
+        '--empty',
       directory,
     ];
 
@@ -188,8 +218,30 @@ base mixin DashCliSupport on ToolsSupport, LoggingSupport, RootsTrackingSupport
           description:
               'The project template to use (e.g., "console-full", "app").',
         ),
+        ParameterNames.platform: Schema.list(
+          items: Schema.string(),
+          description:
+              'The list of platforms this project supports. Only valid '
+              'for Flutter projects. The allowed values are '
+              '${_allowedFlutterPlatforms.map((e) => '`$e`').join(', ')}. '
+              'Defaults to creating a project for all platforms.',
+        ),
+        ParameterNames.empty: Schema.bool(
+          description:
+              'Whether or not to create an "empty" project with minimized '
+              'boilerplate and example code. Defaults to true.',
+        ),
       },
       required: [ParameterNames.directory, ParameterNames.projectType],
     ),
   );
+
+  static const _allowedFlutterPlatforms = {
+    'web',
+    'linux',
+    'macos',
+    'windows',
+    'android',
+    'ios',
+  };
 }

pkgs/dart_mcp_server/lib/src/utils/cli_utils.dart

@@ -292,10 +292,11 @@ ListSchema rootsSchema({bool supportsPaths = false}) => Schema.list(
 );
 
 final rootSchema = Schema.string(
-  title: 'The URI of the project root to run this tool in.',
+  title: 'The file URI of the project root to run this tool in.',
   description:
       'This must be equal to or a subdirectory of one of the roots '
-      'returned by a call to "listRoots".',
+      'allowed by the client. Must be a URI with a `file:` '
+      'scheme (e.g. file:///absolute/path/to/root).',
 );
 
 /// Very thin extension type for a pubspec just containing what we need.

pkgs/dart_mcp_server/lib/src/utils/constants.dart

@@ -9,10 +9,12 @@ extension ParameterNames on Never {
   static const column = 'column';
   static const command = 'command';
   static const directory = 'directory';
+  static const empty = 'empty';
   static const line = 'line';
   static const name = 'name';
   static const packageName = 'packageName';
   static const paths = 'paths';
+  static const platform = 'platform';
   static const position = 'position';
   static const projectType = 'projectType';
   static const query = 'query';

pkgs/dart_mcp_server/lib/src/utils/process_manager.dart

@@ -16,5 +16,5 @@ import 'package:process/process.dart';
 /// implement this class and use [processManager] instead of making direct calls
 /// to dart:io's [Process] class.
 abstract interface class ProcessManagerSupport {
-  LocalProcessManager get processManager;
+  ProcessManager get processManager;
 }

pkgs/dart_mcp_server/test/tools/dart_cli_test.dart

@@ -217,13 +217,74 @@ dependencies:
               'create',
               '--template',
               'app',
+              '--empty',
               'new_app',
             ],
             workingDirectory: exampleFlutterAppRoot.path,
           )),
         ]);
       });
 
+      test('creates a non-empty Flutter project', () async {
+        testHarness.mcpClient.addRoot(exampleFlutterAppRoot);
+        final request = CallToolRequest(
+          name: createProjectTool.name,
+          arguments: {
+            ParameterNames.root: exampleFlutterAppRoot.uri,
+            ParameterNames.directory: 'new_full_app',
+            ParameterNames.projectType: 'flutter',
+            ParameterNames.template: 'app',
+            ParameterNames.empty:
+                false, // Explicitly create a non-empty project
+          },
+        );
+        await testHarness.callToolWithRetry(request);
+
+        expect(testProcessManager.commandsRan, [
+          equalsCommand((
+            command: [
+              endsWith('flutter'),
+              'create',
+              '--template',
+              'app',
+              // Note: --empty is NOT present
+              'new_full_app',
+            ],
+            workingDirectory: exampleFlutterAppRoot.path,
+          )),
+        ]);
+      });
+
+      test('fails with invalid platform for Flutter project', () async {
+        testHarness.mcpClient.addRoot(exampleFlutterAppRoot);
+        final request = CallToolRequest(
+          name: createProjectTool.name,
+          arguments: {
+            ParameterNames.root: exampleFlutterAppRoot.uri,
+            ParameterNames.directory: 'my_app_invalid_platform',
+            ParameterNames.projectType: 'flutter',
+            ParameterNames.platform: ['atari_jaguar', 'web'], // One invalid
+          },
+        );
+        final result = await testHarness.callToolWithRetry(
+          request,
+          expectError: true,
+        );
+
+        expect(result.isError, isTrue);
+        expect(
+          (result.content.first as TextContent).text,
+          allOf(
+            contains('atari_jaguar is not a valid platform.'),
+            contains(
+              'Platforms `web`, `linux`, `macos`, `windows`, `android`, `ios` '
+              'are the only allowed values',
+            ),
+          ),
+        );
+        expect(testProcessManager.commandsRan, isEmpty);
+      });
+
       test('fails if projectType is missing', () async {
         testHarness.mcpClient.addRoot(dartCliAppRoot);
         final request = CallToolRequest(