🐛 | Fix tests

README.md

@@ -110,9 +110,31 @@ Tunetti stores its settings in `~/.config/tunetti/config.json`. Here's what you
 | [PySide6](https://pypi.org/project/PySide6/) | The graphical interface (Qt6) |
 | [pypresence](https://github.com/qwertyquerty/pypresence) | Discord Rich Presence |
 
-## 🧪 Quality checks
+## 🧪 Testing
 
-Code quality is analyzed automatically by SonarQube whenever changes are pushed.
+Tests use **pytest** with **coverage** and are designed to run both locally and in CI (SonarQube picks up the coverage report automatically).
+
+```bash
+# Install test dependencies
+pip install -r requirements-dev.txt
+
+# Run all tests
+.venv/bin/python -m pytest tests/ -v
+
+# Run with coverage (generates coverage.xml for SonarQube)
+.venv/bin/coverage run -m pytest tests/
+.venv/bin/coverage xml
+```
+
+| Module | Coverage | What's covered |
+|---|---|---|
+| `music_db.py` | 100% | All DB operations: record, favourites, history, stats, edge cases |
+| `config.py` | 87% | Load, save, migrate, volume clamping, get/set settings |
+| `discord_rpc.py` | 84% | `_safe_artists` edge cases, DiscordRPC lifecycle, mocked pypresence |
+| `player.py` | 32% | Helpers: `_best_thumbnail`, `_build_song_dict`, `_generate_test_wav`, `_stale_files`, `_build_resolved_dict` |
+| `gui.py` | 12% | Helpers: `_fmt_ms`, `_artists_str`, `_norm_artists`, `_artists_from_json` |
+
+> The Qt GUI/player classes require a display server and PulseAudio — they can't run in headless CI. Guarded imports (in `player.py` and `gui.py`) ensure pure helper functions are still testable anywhere.
 
 ## 📄 License