Add backup-first duplicate repair

tests/test_repair.py

@@ -0,0 +1,67 @@
+from pathlib import Path
+
+import pytest
+
+from serato_doctor.repair import (
+    BACKUP_FOLDER,
+    apply_duplicate_repair,
+    plan_duplicate_repair,
+    restore_backup,
+    rotate_backups,
+)
+
+
+def library(tmp_path):
+    serato = tmp_path / "_Serato_"
+    crate = serato / "Subcrates" / "House.crate"
+    crate.parent.mkdir(parents=True)
+    crate.write_bytes(b"crate-data")
+    (serato / "database V2").write_bytes(b"database-data")
+    music = tmp_path / "Music"
+    keeper = music / "Main" / "Track.mp3"
+    duplicate = music / "Old" / "Track.mp3"
+    keeper.parent.mkdir(parents=True)
+    duplicate.parent.mkdir(parents=True)
+    keeper.write_bytes(b"keeper")
+    duplicate.write_bytes(b"duplicate")
+    return serato, keeper, duplicate
+
+
+def test_duplicate_repair_backs_up_then_preserves_old_path_as_link(tmp_path):
+    serato, keeper, duplicate = library(tmp_path)
+    plan = plan_duplicate_repair(keeper, (keeper, duplicate), serato)
+
+    receipt = apply_duplicate_repair(plan, serato, backup_limit=3)
+
+    assert duplicate.is_symlink()
+    assert duplicate.resolve() == keeper.resolve()
+    assert (receipt.backup / "manifest.json").is_file()
+    assert any((receipt.backup / "serato-metadata").rglob("House.crate"))
+    assert any((receipt.backup / "serato-metadata").rglob("database V2"))
+
+    restored = restore_backup(receipt.backup)
+    assert restored == (duplicate.resolve(),)
+    assert not duplicate.is_symlink()
+    assert duplicate.read_bytes() == b"duplicate"
+
+
+def test_plan_rejects_keeper_outside_duplicate_group(tmp_path):
+    serato, keeper, duplicate = library(tmp_path)
+    outsider = tmp_path / "outsider.mp3"
+    outsider.write_bytes(b"other")
+
+    with pytest.raises(ValueError, match="must belong"):
+        plan_duplicate_repair(outsider, (keeper, duplicate), serato)
+
+
+def test_backup_rotation_can_be_limited_or_unlimited(tmp_path):
+    root = tmp_path / BACKUP_FOLDER
+    for name in ("001", "002", "003"):
+        backup = root / name
+        backup.mkdir(parents=True)
+        (backup / "manifest.json").write_text("{}", encoding="utf-8")
+
+    rotate_backups(root, None)
+    assert len(list(root.iterdir())) == 3
+    rotate_backups(root, 2)
+    assert {path.name for path in root.iterdir()} == {"002", "003"}

tests/test_web.py

@@ -3,7 +3,7 @@ from pathlib import Path
 
 import pytest
 
-from serato_doctor.web import STATIC_FILES, analyze_paths
+from serato_doctor.web import STATIC_FILES, analyze_paths, duplicate_repair
 
 
 def test_web_analysis_uses_production_health_pipeline(tmp_path):
@@ -49,3 +49,24 @@ def test_web_static_assets_are_declared_and_packaged():
     assert 'data-detail="database_missing_tracks"' in html
     assert 'data-detail="old_crate_references"' in html
     assert html.count('class="info-button"') >= 10
+
+
+def test_duplicate_repair_preview_does_not_change_files(tmp_path):
+    serato = tmp_path / "_Serato_"
+    serato.mkdir()
+    music = tmp_path / "Music"
+    first = music / "A" / "Track.mp3"
+    second = music / "B" / "Track.mp3"
+    first.parent.mkdir(parents=True)
+    second.parent.mkdir(parents=True)
+    first.write_bytes(b"first")
+    second.write_bytes(b"second")
+
+    result = duplicate_repair(
+        serato, music, first, (first, second), backup_limit=10
+    )
+
+    assert result["applied"] is False
+    assert result["database_v2_modified"] is False
+    assert second.read_bytes() == b"second"
+    assert not second.is_symlink()