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Template: Clean Architecture Feature ​

The canonical end-to-end Flutter feature: all three layers, the Riverpod DI graph, typed error handling, and tests. This bundle ships representative .dart files you can copy and rename. See architecture/clean_architecture.md and skills/architecture/flutter/clean_architecture.md.

Folder Structure ​

text
clean_architecture_feature/
├── domain.dart          // entity + Failure union + repository interface + use cases
├── data.dart            // DTO + mapper + remote data source + repository impl
├── presentation.dart    // AsyncNotifier + ConsumerWidget with every state handled
├── providers.dart       // composition root — the DI graph
└── feature_test.dart    // mapper + use case + notifier + widget tests

The files use a sample Article feature. Replace Article/article with your entity, and split each file into one-type-per-file when you copy it into a real module. They are illustrative — they are not part of a compiled package, so cross-file symbols won't resolve in isolation.

How the layers connect ​

text
ArticlesScreen → ArticlesNotifier → GetArticles → ArticleRepository (interface)
                                                          ▲
                            ArticleRepositoryImpl (Data) ── ArticleRemoteDataSource ── Dio

Conventions Demonstrated ​

  • Domain is framework-free — domain.dart imports nothing. The entity, the Failure union, the repository interface, and the use cases all live there.
  • Data owns the wire format — ArticleDto and its toEntity() mapper never leave data.dart, and every DioException is translated into a Failure before it crosses the boundary.
  • Presentation is a function of state — the widget renders loading / loaded / empty / error and nothing else; _messageFor maps typed failures to user-facing copy.
  • Providers are typed as Domain interfaces (Provider<ArticleRepository>), which is what makes every edge overridable in a test.
  • Tests override the repository seam with a hand-written fake, so the real notifier and use case logic actually runs. addTearDown(container.dispose) prevents state leaking between tests.
  • Keys on everything a test drives (articles.loading, articles.empty, articles.error, articles.retry) so finders are stable.

Usage ​

  1. Copy the bundle into your feature module (lib/features/<name>/).
  2. Rename Article/article → your entity, and split into per-type files.
  3. Point dioProvider's baseUrl at your configuration provider rather than a literal.
  4. Register the screen in the go_router route table (skills/architecture/flutter/router_navigation.md).
  5. Run flutter analyze and flutter test.