Added missing methods and implemented tests

test/db_tests/group_test.dart

@@ -0,0 +1,130 @@
+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/group.dart';
+import 'package:game_tracker/data/dto/player.dart';
+
+void main() {
+  late AppDatabase database;
+  late Player player1;
+  late Player player2;
+  late Player player3;
+  late Player player4;
+  late Group testgroup;
+
+  setUp(() {
+    database = AppDatabase(
+      DatabaseConnection(
+        NativeDatabase.memory(),
+        // Recommended for widget tests to avoid test errors.
+        closeStreamsSynchronously: true,
+      ),
+    );
+
+    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],
+    );
+  });
+  tearDown(() async {
+    await database.close();
+  });
+
+  test('group and group members gets added correctly', () async {
+    await database.groupDao.addGroup(group: testgroup);
+
+    final result = await database.groupDao.getGroupById(groupId: testgroup.id);
+
+    expect(result.id, testgroup.id);
+    expect(result.name, testgroup.name);
+
+    expect(result.members.length, testgroup.members.length);
+    for (int i = 0; i < testgroup.members.length; i++) {
+      expect(result.members[i].id, testgroup.members[i].id);
+      expect(result.members[i].name, testgroup.members[i].name);
+    }
+  });
+
+  test('group gets deleted correctly', () async {
+    await database.groupDao.addGroup(group: testgroup);
+
+    final groupDeleted = await database.groupDao.deleteGroup(
+      groupId: testgroup.id,
+    );
+    expect(groupDeleted, true);
+
+    final groupExists = await database.groupDao.groupExists(
+      groupId: testgroup.id,
+    );
+    expect(groupExists, false);
+  });
+
+  test('group name gets updated correcly ', () async {
+    await database.groupDao.addGroup(group: testgroup);
+
+    const newGroupName = 'new group name';
+
+    await database.groupDao.updateGroupname(
+      groupId: testgroup.id,
+      newName: newGroupName,
+    );
+
+    final result = await database.groupDao.getGroupById(groupId: testgroup.id);
+    expect(result.name, newGroupName);
+  });
+
+  test('Adding player to group works correctly', () async {
+    await database.groupDao.addGroup(group: testgroup);
+
+    await database.playerGroupDao.addPlayerToGroup(
+      player: player4,
+      groupId: testgroup.id,
+    );
+
+    final playerAdded = await database.playerGroupDao.isPlayerInGroup(
+      playerId: player4.id,
+      groupId: testgroup.id,
+    );
+
+    expect(playerAdded, true);
+
+    final playerAdded2 = await database.playerGroupDao.isPlayerInGroup(
+      playerId: 'a',
+      groupId: testgroup.id,
+    );
+
+    expect(playerAdded2, false);
+
+    expect(playerAdded, true);
+
+    final result = await database.groupDao.getGroupById(groupId: testgroup.id);
+    expect(result.members.length, testgroup.members.length + 1);
+
+    final addedPlayer = result.members.firstWhere((p) => p.id == player4.id);
+    expect(addedPlayer.name, player4.name);
+  });
+
+  test('Removing player from group works correctly', () async {
+    await database.groupDao.addGroup(group: testgroup);
+
+    final playerToRemove = testgroup.members[0];
+
+    final removed = await database.playerGroupDao.removePlayerFromGroup(
+      playerId: playerToRemove.id,
+      groupId: testgroup.id,
+    );
+    expect(removed, true);
+
+    final result = await database.groupDao.getGroupById(groupId: testgroup.id);
+    expect(result.members.length, testgroup.members.length - 1);
+
+    final playerExists = result.members.any((p) => p.id == playerToRemove.id);
+    expect(playerExists, false);
+  });
+}