feat(v2): complete v2 reimplementation

tests/unit/test_restore_selection.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+import importlib
+
+import pytest
+
+snapshot = importlib.import_module("backup_tool.snapshot")
+
+
+def entry(path: str, kind: str) -> dict[str, object]:
+    return {"path": path, "type": kind}
+
+
+def test_restore_selection_includes_selected_descendants_and_ancestors() -> None:
+    entries = [
+        entry("top", "directory"),
+        entry("top/keep", "directory"),
+        entry("top/keep/file.txt", "file"),
+        entry("top/drop.txt", "file"),
+    ]
+
+    selected = snapshot._select_restore_entries(entries, ["top/keep"])
+
+    assert [item["path"] for item in selected] == [
+        "top",
+        "top/keep",
+        "top/keep/file.txt",
+    ]
+
+
+@pytest.mark.parametrize("selection", [["../escape"], ["/absolute"], ["a\\b"], [""]])
+def test_restore_selection_rejects_unsafe_paths(selection: list[str]) -> None:
+    with pytest.raises(snapshot.SnapshotError):
+        snapshot._select_restore_entries([entry("safe", "file")], selection)