Added missing methods and implemented tests

test/db_tests/game_test.dart

@@ -0,0 +1,111 @@
+import 'package:drift/drift.dart';
+import 'package:drift/native.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:game_tracker/data/db/database.dart';
+import 'package:game_tracker/data/dto/game.dart';
+import 'package:game_tracker/data/dto/group.dart';
+import 'package:game_tracker/data/dto/player.dart';
+
+void main() {
+  late AppDatabase database;
+  late Player testPlayer;
+  late Player player1;
+  late Player player2;
+  late Player player3;
+  late Player player4;
+  late Group testgroup;
+  late Game testgame;
+
+  setUp(() {
+    database = AppDatabase(
+      DatabaseConnection(
+        NativeDatabase.memory(),
+        // Recommended for widget tests to avoid test errors.
+        closeStreamsSynchronously: true,
+      ),
+    );
+
+    testPlayer = Player(id: 'test_id', name: 'Test Player');
+    player1 = Player(id: 'p1', name: 'Alice');
+    player2 = Player(id: 'p2', name: 'Bob');
+    player3 = Player(id: 'p3', name: 'Charlie');
+    player4 = Player(id: 'p4', name: 'Diana');
+    testgroup = Group(
+      id: 'gr1',
+      name: 'Test Group',
+      members: [player1, player2, player3],
+    );
+    testgame = Game(
+      id: 'ga1',
+      name: 'Test Game',
+      group: testgroup,
+      players: [player4],
+    );
+  });
+  tearDown(() async {
+    await database.close();
+  });
+
+  group('game tests', () {
+    test('game is added correctly', () async {
+      await database.gameDao.addGame(game: testgame);
+
+      final result = await database.gameDao.getGameById(gameId: testgame.id);
+
+      expect(result.id, testgame.id);
+      expect(result.name, testgame.name);
+      expect(result.winner, testgame.winner);
+
+      if (result.group != null) {
+        expect(result.group!.members.length, testgroup.members.length);
+
+        for (int i = 0; i < testgroup.members.length; i++) {
+          expect(result.group!.members[i].id, testgroup.members[i].id);
+          expect(result.group!.members[i].name, testgroup.members[i].name);
+        }
+      } else {
+        fail('Group is null');
+      }
+      if (result.players != null) {
+        expect(result.players!.length, testgame.players!.length);
+
+        for (int i = 0; i < testgame.players!.length; i++) {
+          expect(result.players![i].id, testgame.players![i].id);
+          expect(result.players![i].name, testgame.players![i].name);
+        }
+      } else {
+        fail('Players is null');
+      }
+    });
+
+    test('game is deleted correctly', () async {
+      await database.gameDao.addGame(game: testgame);
+
+      final gameDeleted = await database.gameDao.deleteGame(
+        gameId: testgame.id,
+      );
+      expect(gameDeleted, true);
+
+      final gameExists = await database.gameDao.gameExists(gameId: testgame.id);
+      expect(gameExists, false);
+    });
+
+    test('get game count works correctly', () async {
+      final initialCount = await database.gameDao.getGameCount();
+      expect(initialCount, 0);
+
+      await database.gameDao.addGame(game: testgame);
+
+      final gameAdded = await database.gameDao.getGameCount();
+      expect(gameAdded, 1);
+
+      final gameRemoved = await database.gameDao.deleteGame(
+        gameId: testgame.id,
+      );
+      expect(gameRemoved, true);
+
+      final finalCount = await database.gameDao.getGameCount();
+      expect(finalCount, 0);
+    });
+  });
+}