Add demo export cleanup tooling

backend/tests/test_sprint24_cleanup_demo_artifacts.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import importlib.util
+from dataclasses import dataclass
+from datetime import datetime, timedelta
+from pathlib import Path
+from types import ModuleType
+
+
+def load_cleanup_module() -> ModuleType:
+    script = Path(__file__).resolve().parents[2] / "scripts" / "cleanup_demo_artifacts.py"
+    spec = importlib.util.spec_from_file_location("cleanup_demo_artifacts", script)
+    assert spec is not None
+    assert spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@dataclass
+class ExportRow:
+    id: str
+    created_at: datetime | None
+    storage_path: str
+
+
+def test_cleanup_candidate_selection_keeps_newest_exports() -> None:
+    cleanup = load_cleanup_module()
+    base = datetime(2026, 1, 1, 12, 0, 0)
+    exports = [
+        ExportRow("old", base, "/tmp/old.json"),
+        ExportRow("new", base + timedelta(days=2), "/tmp/new.json"),
+        ExportRow("middle", base + timedelta(days=1), "/tmp/middle.json"),
+        ExportRow("unknown", None, "/tmp/unknown.json"),
+    ]
+
+    kept, candidates = cleanup.select_cleanup_candidates(exports, keep_latest=2)
+
+    assert [export.id for export in kept] == ["new", "middle"]
+    assert [export.id for export in candidates] == ["old", "unknown"]
+
+
+def test_cleanup_candidate_selection_rejects_negative_keep_latest() -> None:
+    cleanup = load_cleanup_module()
+
+    try:
+        cleanup.select_cleanup_candidates([], keep_latest=-1)
+    except ValueError as exc:
+        assert "keep_latest" in str(exc)
+    else:
+        raise AssertionError("negative keep_latest should fail")
+
+
+def test_cleanup_path_safety_requires_storage_root_containment(tmp_path: Path) -> None:
+    cleanup = load_cleanup_module()
+    storage_root = tmp_path / "storage"
+    safe_export = storage_root / "exports" / "project" / "report.html"
+    unsafe_export = tmp_path / "outside" / "report.html"
+
+    safe_export.parent.mkdir(parents=True)
+    unsafe_export.parent.mkdir(parents=True)
+
+    assert cleanup.is_within_storage_root(safe_export, storage_root) is True
+    assert cleanup.is_within_storage_root(unsafe_export, storage_root) is False
+
+
+def test_cleanup_script_defaults_to_explicit_demo_project() -> None:
+    cleanup = load_cleanup_module()
+    parser = cleanup.build_parser()
+
+    args = parser.parse_args([])
+
+    assert args.project_name == cleanup.DEMO_PROJECT_NAME
+    assert args.keep_latest == 3
+    assert args.apply is False