Book repository implementation

BookRepositoryImpl takes a Session, uses the ORM, and returns domain books.

clean-architecturetutorialserverpod

BookRepositoryImpl is the adapter. It is constructed per request because it holds a Session. Do not register it as a singleton. The composition root builds one when a use case factory is called.

Create lib/src/infra/book/book_repository_impl.dart:

dart

import 'package:serverpod/serverpod.dart';
import 'package:shelf_server/src/domain/book/book_repository.dart';
import 'package:shelf_server/src/domain/book/entities/book.dart';
import 'package:shelf_server/src/generated/protocol.dart';
import 'package:shelf_server/src/infra/book/book_mapper.dart';
import 'package:shelf_server/src/infra/shared/uuid_values.dart';

/// Session-scoped. Construct one per request in [Repositories], never as a singleton.
class BookRepositoryImpl implements BookRepository {
  const BookRepositoryImpl(this._session, {BookMapper? mapper})
    : _mapper = mapper ?? const BookMapper();

  final Session _session;
  final BookMapper _mapper;

  @override
  Future<Book> save(Book book) async {
    final row = _mapper.toRow(book);
    final existing = await StoredBook.db.findById(_session, row.id!);
    final stored = existing == null
        ? await StoredBook.db.insertRow(_session, row)
        : await StoredBook.db.updateRow(_session, row);
    return _mapper.toDomain(stored);
  }

  @override
  Future<Book?> findById(String id) async {
    final row = await StoredBook.db.findById(_session, uuidFromString(id));
    return row == null ? null : _mapper.toDomain(row);
  }

  @override
  Future<List<Book>> list() async {
    final rows = await StoredBook.db.find(_session);
    rows.sort((a, b) => b.createdAt.compareTo(a.createdAt));
    return rows.map(_mapper.toDomain).toList();
  }

  @override
  Future<int> countOnShelf(String shelfId) {
    return StoredBook.db.count(
      _session,
      where: (t) => t.shelfId.equals(uuidFromString(shelfId)),
    );
  }
}

save looks up the id and inserts or updates. Placing a book on a shelf is an update of the same row. The use case does not know that.

list loads the rows and sorts in Dart. A shelf for one person is a bounded set. The ORM find is the query. Sorting after the fetch keeps the contract "newest first" obvious in this file. countOnShelf stays in the database because the number is the only thing the caller needs.

Every method returns Book or a list of Book or an int. None of them returns StoredBook. If a StoredBook appears in an application import, the boundary has leaked.

Next: the wire types.