Added missing methods and implemented tests

test/db_tests/player_test.dart

@@ -0,0 +1,66 @@
+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/player.dart';
+
+void main() {
+  late AppDatabase database;
+  late Player testPlayer;
+
+  setUp(() {
+    database = AppDatabase(
+      DatabaseConnection(
+        NativeDatabase.memory(),
+        // Recommended for widget tests to avoid test errors.
+        closeStreamsSynchronously: true,
+      ),
+    );
+
+    testPlayer = Player(id: 'test_id', name: 'Test Player');
+  });
+  tearDown(() async {
+    await database.close();
+  });
+
+  group('player tests', () {
+    test('players get inserted correcly ', () async {
+      await database.playerDao.addPlayer(player: testPlayer);
+      final result = await database.playerDao.getPlayerById(
+        playerId: testPlayer.id,
+      );
+
+      expect(result.id, testPlayer.id);
+      expect(result.name, testPlayer.name);
+    });
+
+    test('players get deleted correcly ', () async {
+      await database.playerDao.addPlayer(player: testPlayer);
+      final playerDeleted = await database.playerDao.deletePlayer(
+        playerId: testPlayer.id,
+      );
+      expect(playerDeleted, true);
+
+      final playerExists = await database.playerDao.playerExists(
+        playerId: testPlayer.id,
+      );
+      expect(playerExists, false);
+    });
+
+    test('player name gets updated correcly ', () async {
+      await database.playerDao.addPlayer(player: testPlayer);
+
+      const newPlayerName = 'new player name';
+
+      await database.playerDao.updatePlayername(
+        playerId: testPlayer.id,
+        newName: newPlayerName,
+      );
+
+      final result = await database.playerDao.getPlayerById(
+        playerId: testPlayer.id,
+      );
+      expect(result.name, newPlayerName);
+    });
+  });
+}