dart user service, dependency injection with riverpod

_common/db_client/lib/db_client.dart

@@ -1,3 +1 @@
-int calculate() {
-  return 6 * 7;
-}
+

_common/db_client/test/db_client_test.dart

@@ -1,8 +0,0 @@
-import 'package:db_client/db_client.dart';
-import 'package:test/test.dart';
-
-void main() {
-  test('calculate', () {
-    expect(calculate(), 42);
-  });
-}