Add more tests for PlaylistDownloader functionality

tests/test_renumber_and_cleanup.py

@@ -0,0 +1,61 @@
+import shutil
+from pathlib import Path
+
+from ytplaylist.downloader import PlaylistDownloader
+from tests.dummy_config import DummyConfig
+
+
+def touch(p: Path):
+    p.parent.mkdir(parents=True, exist_ok=True)
+    p.write_text("x")
+
+
+def test_renumber_all_tracks_and_cleanup(tmp_path):
+    cfg = DummyConfig()
+    playlist = {"url": "FAKE", "save_path": str(tmp_path)}
+    dl = PlaylistDownloader(cfg, playlist, 0)
+    # set download mode to both so both folders are considered
+    dl.download_mode = "both"
+
+    # Create sample playlist entries with titles that will produce safe_title
+    entries = [
+        {"id": "ID1", "title": "First Song"},
+        {"id": "ID2", "title": "Second Song"},
+    ]
+
+    # create files with wrong prefixes
+    a1 = tmp_path / "audio" / "oldname First Song.mp3"
+    a2 = tmp_path / "audio" / "zzz Second Song.mp3"
+    v1 = tmp_path / "video" / "oops First Song.mp4"
+    v2 = tmp_path / "video" / "another Second Song.mp4"
+
+    touch(a1)
+    touch(a2)
+    touch(v1)
+    touch(v2)
+
+    # Run renumbering
+    dl.renumber_all_tracks(entries)
+
+    # Check that files have been renamed to expected NNN - title.ext
+    audio_files = list((tmp_path / "audio").glob("*.mp3"))
+    video_files = list((tmp_path / "video").glob("*.mp4"))
+
+    assert any(f.name.startswith("001 - First Song") for f in audio_files)
+    assert any(f.name.startswith("002 - Second Song") for f in audio_files)
+    assert any(f.name.startswith("001 - First Song") for f in video_files)
+    assert any(f.name.startswith("002 - Second Song") for f in video_files)
+
+    # Now test cleanup_removed_tracks: create a stray file not in entries
+    stray = tmp_path / "audio" / "999 - NotInPlaylist.mp3"
+    touch(stray)
+    # ensure prune=False -> no deletion
+    dl.prune = False
+    dl.cleanup_removed_tracks(entries)
+    assert stray.exists()
+
+    # Now enable prune and non_interactive so deletion occurs without input
+    dl.prune = True
+    dl.non_interactive = True
+    dl.cleanup_removed_tracks(entries)
+    assert not stray.exists()