Added tests for bug causing behaviour

test/db_tests/group_game_test.dart

@@ -1,5 +1,5 @@
 import 'package:clock/clock.dart';
-import 'package:drift/drift.dart';
+import 'package:drift/drift.dart' hide isNotNull;
 import 'package:drift/native.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:game_tracker/data/db/database.dart';
@@ -189,5 +189,33 @@ void main() {
         }
       }
     });
+
+    test('Adding the same group to seperate matches works correctly', () async {
+      final match1 = Match(name: 'Match 1', group: testGroup1);
+      final match2 = Match(name: 'Match 2', group: testGroup1);
+
+      await Future.wait([
+        database.matchDao.addMatch(match: match1),
+        database.matchDao.addMatch(match: match2),
+      ]);
+
+      final group1 = await database.groupMatchDao.getGroupOfMatch(
+        matchId: match1.id,
+      );
+      final group2 = await database.groupMatchDao.getGroupOfMatch(
+        matchId: match2.id,
+      );
+
+      expect(group1, isNotNull);
+      expect(group2, isNotNull);
+
+      final groups = [group1!, group2!];
+      for (final group in groups) {
+        expect(group.members.length, testGroup1.members.length);
+        expect(group.id, testGroup1.id);
+        expect(group.name, testGroup1.name);
+        expect(group.createdAt, testGroup1.createdAt);
+      }
+    });
   });
 }