颤振:如何单元测试moor/drift?

Question

我已经为本地存储实现了Drift，并希望使其成为可测试的函数。但是我得到了堆栈，我不知道如何在单元测试中修复它。

HomeDao

@DriftAccessor(tables: [RepositoriesTable])
class HomeDao extends DatabaseAccessor<AppDatabase> with _$HomeDaoMixin {
HomeDao(AppDatabase db) : super(db);
Future<List<RepositoriesTableData>> getRepositories() async =>
await select(repositoriesTable).get();
}

AppDatabase

@DriftDatabase(
tables: [RepositoriesTable],
daos: [HomeDao],
)
class AppDatabase extends _$AppDatabase {
AppDatabase() : super(_openConnection());
@override
int get schemaVersion => 1;
}
QueryExecutor _openConnection() {
return SqfliteQueryExecutor.inDatabaseFolder(
path: 'db.sqlite',
logStatements: true,
);
}

使用localdatasource

abstract class GTHomeLocalDataSource {
const GTHomeLocalDataSource();
Future<List<RepositoriesTableData>> getRepositories();
}
class GTHomeLocalDataSourceImpl implements GTHomeLocalDataSource {
final AppDatabase appDatabase;
const GTHomeLocalDataSourceImpl({required this.appDatabase});
@override
Future<List<RepositoriesTableData>> getRepositories() async =>
await appDatabase.homeDao.getRepositories();
}

unittest

void main() => testGTHomeLocalDataSource();
class MockDatabaseHandler extends Mock implements AppDatabase {}
void testGTHomeLocalDataSource() {
late GTHomeLocalDataSource localDataSource;
late AppDatabase databaseHandler;
setUp(() {
databaseHandler = MockDatabaseHandler();
localDataSource = GTHomeLocalDataSourceImpl(
appDatabase: databaseHandler,
);
});
group("GTHomeLocalDataSource -", () {
test(''' t
GIVEN Nothing
WHEN call getRepositories
THEN databaseHandler select function has been called and return list of RepositoriesTableData
''', () async {
// GIVEN
when(() => databaseHandler.homeDao.getRepositories())
.thenAnswer((_) => Future.value(repositoriesDummyTable));
// WHEN
final result = await localDataSource.getRepositories();
// THEN
verify(() => databaseHandler.homeDao.getRepositories());
expect(result, isA<List<RepositoriesTableData>>());
expect(result.length, repositoriesDummyTable.length);
expect(result.first.language, repositoriesDummyTable.first.language);
});
});
tearDown(() async {
await databaseHandler.close();
});
}

我的功能很好地从本地数据库获取数据，并在应用程序中显示它，但是当作为单元测试运行时，我堆叠了这个错误。

package:gt_core/local/database/database_module.g.dart 424:22           MockDatabaseHandler.homeDao
package:gt_home/data/data_sources/gt_home_local_datasource.dart 20:25  GTHomeLocalDataSourceImpl.getRepositories
test/data/data_sources/gt_home_local_datasource_test.dart 35:44        testGTHomeLocalDataSource.<fn>.<fn>
test/data/data_sources/gt_home_local_datasource_test.dart 29:12        testGTHomeLocalDataSource.<fn>.<fn>
type 'Null' is not a subtype of type 'Future<void>'
package:drift/src/runtime/api/db_base.dart 125:16                MockDatabaseHandler.close
test/data/data_sources/gt_home_local_datasource_test.dart 47:27  testGTHomeLocalDataSource.<fn>
test/data/data_sources/gt_home_local_datasource_test.dart 46:12  testGTHomeLocalDataSource.<fn>
===== asynchronous gap ===========================
dart:async                                                       _completeOnAsyncError
test/data/data_sources/gt_home_local_datasource_test.dart        testGTHomeLocalDataSource.<fn>
test/data/data_sources/gt_home_local_datasource_test.dart 46:12  testGTHomeLocalDataSource.<fn>
type 'Future<List<RepositoriesTableData>>' is not a subtype of type 'HomeDao'

有人知道怎么修理它吗?

Answer 1

如果您使用mock来测试Drift数据库，那么您也需要mock方法调用，否则该方法将返回null，这是mock的默认行为。例如,

// return rowid
when(db.insertItem(any)).thenAnswer((_) => 1);

然而，根据Drift文档，建议使用内存中的sqlite数据库，它不需要真正的设备或模拟器进行测试。

这个问题也在这里讨论过

使用内存数据库

import 'package:drift/native.dart';
import 'package:test/test.dart';
import 'package:my_app/src/database.dart'; 
void main() {
MyDatabase database;
MyRepo repo;
setUp(() {
database = MyDatabase(NativeDatabase.memory());
repo = MyRepo(appDatabase: database);
});
tearDown(() async {
await database.close();
});
group('mytest', () {
test('test create', () async {
await repo.create(MyDateCompanion(title: 'some name'));
final list = await repo.getItemList();
expect(list, isA<MyDataObject>())
})
});
}