flutter ddd feature first 开发最佳实践

基于 分离 + CodeGen 映射 的最佳实践开发流程，涵盖从领域建模到 DTO、映射、仓库实现、UseCase、ViewModel、UI，再到各层单元／集成测试和 CI 集成。按此流程，既能保持清晰分层，又能用工具最大化减少样板、提高维护效率。

一、领域层（Domain）

定义实体（Entity）和值对象（Value Object）

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// lib/features/members/domain/entities/member_entity.dart
class MemberEntity {
  final String name;
  final String accountId;
  final String accountRole;
  final int accountStatus;

  MemberEntity({
    required this.name,
    required this.accountId,
    required this.accountRole,
    required this.accountStatus,
  });

  bool get isActive => accountStatus == 1;
}

定义领域请求／响应模型

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// lib/features/members/domain/entities/member_update_item.dart
class MemberUpdateItem {
  final int? accountStatus;
  final int? resetPassword;
  MemberUpdateItem({this.accountStatus, this.resetPassword});
}

// lib/features/members/domain/entities/member_creation_request.dart
class ManagerCreationInfo {
  final String accountId, name;
  /*…*/
}
class SupportCreationInfo {
  final int createNum;
  /*…*/
}

定义仓库接口

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// lib/features/members/domain/repositories/member_repository.dart
abstract class MemberRepository {
  Future<List<MemberEntity>> fetchTeamMembers(int teamId);
  Future<bool> updateMemberStatus(String accountId, MemberUpdateItem item);
  Future<List<MemberEntity>> createTeamMembers({
    required int teamId,
    ManagerCreationInfo? manager,
    SupportCreationInfo? support,
  });
}

二、数据层（Data / Infrastructure）

1. 定义 DTO（只做 JSON 序列化）

在 lib/features/members/data/dto/ 下，用 @JsonSerializable(fieldRename: FieldRename.snake)：

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// member_dto.dart
@JsonSerializable(fieldRename: FieldRename.snake)
class MemberDto {
  final String name;
  final String accountId;
  final String accountRole;
  final int accountStatus;

  factory MemberDto.fromJson(Map<String, dynamic> json) => _$MemberDtoFromJson(json);
  Map<String, dynamic> toJson() => _$MemberDtoToJson(this);
}

同理定义 MemberUpdateItemDto, ManagerCreationInfoDto, SupportCreationInfoDto, MemberCreationResponseDto 等。

2. 生成序列化代码

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flutter pub run build_runner build --delete-conflicting-outputs

3. 写 Mapper Extension（DTO → Entity）

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// lib/features/members/data/mappers/member_mapper.dart
extension MemberDtoX on MemberDto {
  MemberEntity toEntity() => MemberEntity(
    name: name,
    accountId: accountId,
    accountRole: accountRole,
    accountStatus: accountStatus,
  );
}

extension MemberCreationResponseDtoX on MemberCreationResponseDto {
  List<MemberEntity> toMemberEntities() {
    final out = <MemberEntity>[];
    if (manager != null) out.add(manager!.toMemberEntity());
    if (support != null) out.addAll(support!.toMemberEntities());
    return out;
  }
}

三、仓库实现（RepositoryImpl）

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// lib/features/members/data/repositories/member_repository_impl.dart
class MemberRepositoryImpl implements MemberRepository {
  final MCRequestManager _api;
  MemberRepositoryImpl(this._api);

  @override
  Future<List<MemberEntity>> fetchTeamMembers(int teamId) async {
    final res = await _api.getTeamMemberListAsync(teamId);
    final dtos = (res['members'] as List)
      .map((e) => MemberDto.fromJson(e)).toList();
    return dtos.map((d) => d.toEntity()).toList();
  }

  @override
  Future<bool> updateMemberStatus(String accountId, MemberUpdateItem item) async {
    final dto = MemberUpdateItemDto(
      accountStatus: item.accountStatus, resetPassword: item.resetPassword);
    await _api.updateTeamMemberAsync(accountId, dto.toJson());
    return true;
  }

  @override
  Future<List<MemberEntity>> createTeamMembers({
    required int teamId,
    ManagerCreationInfo? manager,
    SupportCreationInfo? support,
  }) async {
    final managerDto = manager != null
      ? ManagerCreationInfoDto(accountId: manager.accountId, name: manager.name)
      : null;
    final supportDto = support != null
      ? SupportCreationInfoDto(createNum: support.createNum)
      : null;

    final data = await _api.createTeamMemberAsync(
      teamId,
      manager: managerDto?.toJson(),
      support: supportDto?.toJson(),
    );
    final respDto = MemberCreationResponseDto.fromJson(data);
    return respDto.toMemberEntities();
  }
}

四、应用层（Application）

为每个业务场景写 UseCase。

1. LoadMembersUseCase

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class LoadMembersUseCase {
  final MemberRepository _repo;
  LoadMembersUseCase(this._repo);

  Future<List<MemberEntity>> execute(int teamId) =>
    _repo.fetchTeamMembers(teamId);
}

2. UpdateMemberStatusUseCase

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class UpdateMemberStatusUseCase {
  final MemberRepository _repo;
  UpdateMemberStatusUseCase(this._repo);

  Future<bool> execute(String accountId, int newStatus) =>
    _repo.updateMemberStatus(accountId, MemberUpdateItem(accountStatus: newStatus));
}

3. CreateMembersUseCase

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class CreateMembersUseCase {
  final MemberRepository _repo;
  CreateMembersUseCase(this._repo);

  Future<List<MemberEntity>> execute({
    required int teamId,
    ManagerCreationInfo? manager,
    SupportCreationInfo? support,
  }) => _repo.createTeamMembers(teamId: teamId, manager: manager, support: support);
}

五、表现层（Presentation）

1. State + ViewModel

定义状态类和 StateNotifier，注入 UseCase。

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class MembersState { /* status, list, error */ }

class MembersViewModel extends StateNotifier<MembersState> {
  final LoadMembersUseCase _load;
  final UpdateMemberStatusUseCase _update;
  final CreateMembersUseCase _create;
  MembersViewModel(this._load, this._update, this._create) : super(MembersState());
  Future<void> load(int teamId) async { /*…*/ }
  Future<void> update(String id, int status) async { /*…*/ }
  Future<void> create({…}) async { /*…*/ }
}

2. Provider 注册

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final loadUseCaseProvider = Provider((ref) => LoadMembersUseCase(ref.read(repo)));
final viewModelProvider = StateNotifierProvider.family<MembersViewModel, MembersState, int>((ref, teamId) => MembersViewModel(
  ref.read(loadUseCaseProvider),
  ref.read(updateUseCaseProvider),
  ref.read(createUseCaseProvider),
)..load(teamId));

3. Widget 调用

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class MembersPage extends ConsumerWidget {
  Widget build(...) {
    final state = ref.watch(viewModelProvider(teamId));
    ref.listen(viewModelProvider(teamId), (_, s) { if (s.isError) showError(...); });
    return state.isLoading ? Loading() : CustomTable(items: state.list, ...);
  }
}

六、测试策略

1. 单元测试（UseCase/Mapper/ViewModel）

  • UseCase：用 Mockito 生成 MockMemberRepository，测试 execute 成功／失败分支。
  • Mapper：给一个 DTO 测 dto.toEntity() 输出符合预期。
  • ViewModel：用 ProviderContainer override UseCase Provider，驱动 state 变化测试。

2. 集成测试（RepositoryImpl）

在专门的测试环境上跑 MemberRepositoryImpl.fetchTeamMembers 等方法，验证真实 API、JSON 解析、映射流程。

3. CI 集成

  • 阶段 1：CI 每次提交 flutter test --coverage，跑单元测试。
  • 阶段 2：定时或手动触发少量集成测试，保证后端兼容。
  • 阶段 3：可选 E2E/UI 测试，保证整个用户流畅。

七、工具 & 脚本

  • CodeGen：build_runner + json_serializable +（可选）dart_mappable
  • Mock：mockito + build_runner
  • Lint & CI：确保 build_runner build 无报错，所有测试覆盖率可观。