Add comprehensive tests for playlist service and refactor socket service tests

- Introduced a new test suite for the PlaylistService covering various functionalities including creation, retrieval, updating, and deletion of playlists.
- Added tests for handling sounds within playlists, ensuring correct behavior when adding/removing sounds and managing current playlists.
- Refactored socket service tests for improved readability by adjusting function signatures.
- Cleaned up unnecessary whitespace in sound normalizer and sound scanner tests for consistency.
- Enhanced audio utility tests to ensure accurate hash and size calculations, including edge cases for nonexistent files.
- Removed redundant blank lines in cookie utility tests for cleaner code.

app/services/extraction.py

@@ -14,6 +14,7 @@ from app.models.extraction import Extraction
 from app.models.sound import Sound
 from app.repositories.extraction import ExtractionRepository
 from app.repositories.sound import SoundRepository
+from app.services.playlist import PlaylistService
 from app.services.sound_normalizer import SoundNormalizerService
 from app.utils.audio import get_audio_duration, get_file_hash, get_file_size
 
@@ -41,6 +42,7 @@ class ExtractionService:
         self.session = session
         self.extraction_repo = ExtractionRepository(session)
         self.sound_repo = SoundRepository(session)
+        self.playlist_service = PlaylistService(session)
 
         # Ensure required directories exist
         self._ensure_directories()
@@ -447,20 +449,18 @@ class ExtractionService:
     async def _add_to_main_playlist(self, sound: Sound, user_id: int) -> None:
         """Add the sound to the user's main playlist."""
         try:
-            # This is a placeholder - implement based on your playlist logic
-            # For now, we'll just log that we would add it to the main playlist
+            await self.playlist_service.add_sound_to_main_playlist(sound.id, user_id)
             logger.info(
-                "Would add sound %d to main playlist for user %d",
+                "Added sound %d to main playlist for user %d",
                 sound.id,
                 user_id,
             )
 
-        except Exception as e:
+        except Exception:
             logger.exception(
-                "Error adding sound %d to main playlist for user %d: %s",
+                "Error adding sound %d to main playlist for user %d",
                 sound.id,
                 user_id,
-                e,
             )
             # Don't fail the extraction if playlist addition fails