Claude Code × Flutter 実践アプリ開発 — Dart × AI で加速するモバイル開発

// lib/features/wallpaper/presentation/wallpaper_list_notifier.dart
import 'package:riverpod_annotation/riverpod_annotation.dart';
import '../data/wallpaper_repository.dart';
import '../domain/wallpaper.dart';
import '../domain/wallpaper_cursor.dart';
 
part 'wallpaper_list_notifier.g.dart';
 
@riverpod
class WallpaperListNotifier extends _$WallpaperListNotifier {
  @override
  Future<List<Wallpaper>> build() async {
    return _fetchPage(null);
  }
 
  Future<List<Wallpaper>> _fetchPage(String? cursor) async {
    final repo = ref.read(wallpaperRepositoryProvider);
    try {
      final result = await repo.fetchWallpapers(cursor: cursor);
      return result.items;
    } on NetworkException catch (e) {
      throw WallpaperNetworkError(message: e.message);
    } on ServerException catch (e) {
      throw WallpaperServerError(statusCode: e.statusCode);
    }
  }
 
  /// お気に入り追加（楽観的更新）
  Future<void> toggleFavorite(String wallpaperId) async {
    // 現在の状態を保持（ロールバック用）
    final previous = state;
    // 楽観的に UI を更新
    state = AsyncData(
      state.value!.map((w) {
        return w.id == wallpaperId
            ? w.copyWith(isFavorite: !w.isFavorite)
            : w;
      }).toList(),
    );
    try {
      await ref.read(wallpaperRepositoryProvider)
          .toggleFavorite(wallpaperId);
    } catch (e) {
      // 失敗時はロールバック
      state = previous;
      rethrow;
    }
  }
}

// lib/core/theme/app_theme.dart
// このファイルを先に Claude Code に読み込ませてからウィジェットを生成する
 
class AppColors {
  static const primary = Color(0xFF6750A4);
  static const onPrimary = Color(0xFFFFFFFF);
  static const surface = Color(0xFFFEF7FF);
  // ...
}
 
class AppTextStyles {
  static const headlineLarge = TextStyle(
    fontSize: 32, fontWeight: FontWeight.w400,
  );
  // ...
}

// test/features/wallpaper/presentation/wallpaper_card_test.dart
import 'package:flutter_test/flutter_test.dart';
import 'package:mocktail/mocktail.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
 
class MockWallpaperRepository extends Mock 
    implements WallpaperRepository {}
 
void main() {
  late MockWallpaperRepository mockRepo;
 
  setUp(() {
    mockRepo = MockWallpaperRepository();
  });
 
  group('WallpaperCard', () {
    testWidgets('タイトルとサムネイルが正しく表示される', (tester) async {
      const testWallpaper = Wallpaper(
        id: 'test-1',
        title: 'テスト壁紙',
        imageUrl: 'https://example.com/test.jpg',
        isFavorite: false,
      );
 
      await tester.pumpWidget(
        ProviderScope(
          overrides: [
            wallpaperRepositoryProvider.overrideWithValue(mockRepo),
          ],
          child: const MaterialApp(
            home: Scaffold(body: WallpaperCard(wallpaper: testWallpaper)),
          ),
        ),
      );
 
      expect(find.text('テスト壁紙'), findsOneWidget);
      expect(find.byType(CachedNetworkImage), findsOneWidget);
    });
 
    testWidgets('お気に入りボタンのタップで toggleFavorite が呼ばれる', 
        (tester) async {
      // ... テスト実装
    });
  });
}

# Claude Code に以下を実行させる
 
# iOS リリースビルド
flutter build ipa --release \
  --export-options-plist=ios/ExportOptions.plist
 
# Android App Bundle
flutter build appbundle --release \
  --target-platform android-arm,android-arm64,android-x64

// lib/l10n/app_ja.arb
{
  "@@locale": "ja",
  "appTitle": "壁紙コレクション",
  "@appTitle": { "description": "アプリのタイトル" },
  "favoriteAdded": "{title}をお気に入りに追加しました",
  "@favoriteAdded": {
    "description": "お気に入り追加メッセージ",
    "placeholders": {
      "title": { "type": "String" }
    }
  }
}
 
// lib/l10n/app_en.arb（Claude Code が生成）
{
  "@@locale": "en",
  "appTitle": "Wallpaper Collection",
  "favoriteAdded": "Added {title} to favorites",
  "@favoriteAdded": {
    "description": "Favorite added message",
    "placeholders": {
      "title": { "type": "String" }
    }
  }
}