fix: prevent overwriting saved queue with empty track lists in repository and music player

tests/test_music_player.py

@@ -296,6 +296,36 @@ class MusicPlayerQueueTest(unittest.IsolatedAsyncioTestCase):
         with self.assertRaisesRegex(ValueError, "not connected"):
             await player.restore_queue(GUILD)
 
+    def test_save_queue_does_not_overwrite_with_empty_queue(self):
+        with tempfile.TemporaryDirectory() as directory:
+            player, _ = build_player()
+            player._queues = QueueRepository(directory)
+            saved = [{"id": "saved", "title": "Saved", "plays_left": 2}]
+            player._queues.save(GUILD, saved)
+
+            # Kolejka w stanie odtwarzacza jest pusta
+            player.state(GUILD).queue = []
+            player.save_queue(GUILD)
+
+            # Zapisana wcześniej kolejka powinna pozostać nienaruszona
+            self.assertEqual(player._queues.load(GUILD), saved)
+
+    def test_save_queue_does_not_save_when_all_plays_consumed(self):
+        with tempfile.TemporaryDirectory() as directory:
+            player, _ = build_player()
+            player._queues = QueueRepository(directory)
+            saved = [{"id": "saved", "title": "Saved", "plays_left": 2}]
+            player._queues.save(GUILD, saved)
+
+            # Wszystkie utwory w kolejce mają plays_left = 0
+            track = FakeTrack("consumed")
+            track.plays_left = 0
+            player.state(GUILD).queue = [track]
+            player.save_queue(GUILD)
+
+            # Zapisana wcześniej kolejka powinna pozostać nienaruszona
+            self.assertEqual(player._queues.load(GUILD), saved)
+
 
 class LoopModeTest(unittest.TestCase):
     def test_cycle_order(self):

tests/test_queue_repository.py

@@ -20,6 +20,22 @@ class QueueRepositoryTest(unittest.TestCase):
             self.assertTrue((Path(directory) / "10.json").exists())
             self.assertTrue((Path(directory) / "20.json").exists())
 
+    def test_save_empty_tracks_does_nothing(self):
+        with tempfile.TemporaryDirectory() as directory:
+            repository = QueueRepository(directory)
+            tracks = [{"id": "first", "title": "First", "plays_left": 2}]
+
+            repository.save(10, tracks)
+            self.assertEqual(repository.load(10), tracks)
+
+            # Próba zapisania pustej listy nie powinna nadpisać poprzedniej
+            repository.save(10, [])
+            self.assertEqual(repository.load(10), tracks)
+
+            # Zapis pustej kolejki dla nowego serwera nie powinien tworzyć pliku
+            repository.save(20, [])
+            self.assertFalse(repository.exists(20))
+
 
 if __name__ == "__main__":
     unittest.main()