andrelucassvt/configure-di

Configure DI (Dependency Injection) — Flutter

Leitura Rápida

• GetIt é o único service locator: use AppInjector.inject.
• Quando registrar um Cubit: SEMPRE registerFactory — nunca singleton.
• Quando registrar Service/Repository/DataSource/Dio: SEMPRE registerLazySingleton.
• Quando adicionar dependências: siga a ordem — flavor → services → network → datasources → repositories → cubits.
• Quando resolver dependência na View: AppInjector.inject.get<XCubit>() e feche no dispose().

---

Estrutura

lib/config/
├── app_initializer.dart       # Inicialização central
└── inject/
    └── app_injector.dart      # Configuração de DI

---

Template de AppInjector

import 'package:base_app/common/services/shared_preferences_service.dart';
import 'package:base_app/common/services/storage_service.dart';
import 'package:base_app/config/network/dio_client.dart';
import 'package:base_app/data/datasources/home_remote_datasource.dart';
import 'package:base_app/data/repositories/home_repository_impl.dart';
import 'package:base_app/domain/interfaces/home_repository.dart';
import 'package:base_app/presentation/home/view_model/home_cubit.dart';
import 'package:base_app/presentation/splash/view_model/splash_cubit.dart';
import 'package:dio/dio.dart';
import 'package:get_it/get_it.dart';

enum AppFlavor { development, staging, production }

class AppInjector {
  static GetIt inject = GetIt.instance;

  static Future<void> setupDependencies({required AppFlavor flavor}) async {
    // 1. Flavor
    inject.registerLazySingleton<AppFlavor>(() => flavor);

    final baseUrl = _getBaseUrlForFlavor(flavor);
    final enableLogs = flavor != AppFlavor.production;

    // 2. Services
    inject.registerLazySingleton<StorageService>(
      () => SharedPreferencesService(),
    );

    // 3. Network
    inject.registerLazySingleton<Dio>(
      () => makeDio(baseUrl: baseUrl, enableLogs: enableLogs),
    );

    // 4. DataSources
    inject.registerLazySingleton<HomeRemoteDataSource>(
      () => HomeRemoteDataSource(inject()),
    );

    // 5. Repositories
    inject.registerLazySingleton<HomeRepository>(
      () => HomeRepositoryImpl(inject()),
    );

    // 6. Cubits (SEMPRE Factory)
    inject.registerFactory<HomeCubit>(() => HomeCubit(inject()));
    inject.registerFactory<SplashCubit>(() => SplashCubit());
  }

  static String _getBaseUrlForFlavor(AppFlavor flavor) {
    return switch (flavor) {
      AppFlavor.development => 'https://dev-api.example.com',
      AppFlavor.staging => 'https://staging-api.example.com',
      AppFlavor.production => 'https://api.example.com',
    };
  }
}

---

Tipos de Registro

registerLazySingleton — Services, Repositories, DataSources, Network

// ✅ USE PARA:
inject.registerLazySingleton<StorageService>(() => SharedPreferencesService());
inject.registerLazySingleton<Dio>(() => makeDio(baseUrl: 'https://api.com'));
inject.registerLazySingleton<UserRepository>(() => UserRepositoryImpl(inject()));
inject.registerLazySingleton<UserRemoteDataSource>(() => UserRemoteDataSource(inject()));

registerFactory — Cubits (SEMPRE)

// ✅ USE PARA CUBITS:
inject.registerFactory<HomeCubit>(() => HomeCubit(inject()));
inject.registerFactory<ProfileCubit>(() => ProfileCubit(inject(), inject()));

---

Adicionando uma Nova Feature (checklist)

DataSource:

inject.registerLazySingleton<ProductRemoteDataSource>(
  () => ProductRemoteDataSource(inject()),
);

Repository:

// 1. Interface em lib/domain/interfaces/
// 2. Implementação em lib/data/repositories/
inject.registerLazySingleton<ProductRepository>(
  () => ProductRepositoryImpl(inject()),
);

Cubit:

inject.registerFactory<ProductsCubit>(
  () => ProductsCubit(inject()),
);

---

Resolvendo na View

class _HomeViewState extends State<HomeView> {
  final _cubit = AppInjector.inject.get<HomeCubit>();

  @override
  void dispose() {
    _cubit.close();  // ✅ Sempre feche
    super.dispose();
  }
}

Múltiplas Dependências

// No DI
inject.registerFactory<ProfileCubit>(
  () => ProfileCubit(
    inject<UserRepository>(),  // ✅ Especifica tipo
    inject<StorageService>(),
  ),
);

---

Multi-Flavor Configuration

// Registro
inject.registerLazySingleton<AppFlavor>(() => flavor);

// Acesso em qualquer lugar
final flavor = AppInjector.inject<AppFlavor>();
if (flavor == AppFlavor.development) {
  log('Debug mode');
}

---

Testando com DI

void main() {
  setUp(() {
    AppInjector.inject.reset();
  });

  test('should load home data', () async {
    final mockRepository = MockHomeRepository();
    AppInjector.inject.registerLazySingleton<HomeRepository>(() => mockRepository);
    final cubit = HomeCubit(AppInjector.inject<HomeRepository>());
    // ... teste
  });
}

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Checklist ao Adicionar Dependência

• [ ] Ordem correta: flavor → services → network → datasources → repositories → cubits
• [ ] Cubits com registerFactory, resto com registerLazySingleton
• [ ] Tipo explícito ao resolver: inject<UserRepository>()
• [ ] Cubit fechado no dispose() da View

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Erros Comuns

| Erro | Correto | |---|---| | registerLazySingleton<HomeCubit>(...) | registerFactory<HomeCubit>(...) | | inject.get() sem tipo | inject.get<HomeCubit>() | | Cubit registrado antes do Repository | Registre dependências ANTES de quem as usa | | Não chamar _cubit.close() no dispose | Sempre feche o Cubit no dispose() |

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Resumo das regras de ouro:

• ✅ Cubits são sempre Factory
• ✅ Repositories são sempre LazySingleton
• ✅ Registre dependências antes de usá-las
• ✅ Especifique tipo explícito ao resolver
• ✅ Feche Cubits no dispose()

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Última atualização: 28 de março de 2026