Repair backup revisions that recorded a mapped drive

tests/test_fix_drive_letter_sharepaths.py

@@ -0,0 +1,58 @@
+"""The path rewrite, exercised without a database.
+
+rewrite() is pure on purpose: the risky part of this script is deciding WHICH
+paths to touch, and that judgement should be testable without standing up an
+app context.
+"""
+
+import importlib.util
+from pathlib import Path
+
+import pytest
+
+SCRIPT = Path(__file__).resolve().parent.parent / 'scripts' / 'fix_drive_letter_sharepaths.py'
+
+
+def _rewrite(*args, **kwargs):
+    # Imported lazily and by path: scripts/ is not a package, and importing the
+    # module runs load_dotenv + create_app imports at module scope.
+    spec = importlib.util.spec_from_file_location('fixsharepaths', SCRIPT)
+    module = importlib.util.module_from_spec(spec)
+    try:
+        spec.loader.exec_module(module)
+    except Exception as exc:  # pragma: no cover - env-dependent
+        pytest.skip('script imports need an app environment: {}'.format(exc))
+    return module.rewrite(*args, **kwargs)
+
+
+# Generic on purpose: a real site hostname in a test is still a site
+# hostname in the published repo (ADR-015), and the rewrite does not care
+# which server it is.
+UNC = r'\\fileserver\share\path'
+
+
+def test_a_mapped_drive_path_becomes_its_unc_equivalent():
+    got = _rewrite(r'W:\backup\partmarker\WJPRT\20260825-144500', 'W:', UNC)
+    assert got == UNC + r'\backup\partmarker\WJPRT\20260825-144500'
+
+
+def test_a_path_that_is_already_unc_is_left_alone():
+    """The script repairs a known mistake; it does not normalise what it finds."""
+    assert _rewrite(UNC + r'\backup\partmarker\WJPRT\x', 'W:', UNC) is None
+
+
+def test_another_drive_is_left_alone():
+    assert _rewrite(r'S:\DT\Shopfloor\backup\x', 'W:', UNC) is None
+
+
+def test_an_empty_or_missing_path_is_left_alone():
+    assert _rewrite('', 'W:', UNC) is None
+    assert _rewrite(None, 'W:', UNC) is None
+
+
+def test_the_drive_letter_match_is_case_insensitive():
+    assert _rewrite(r'w:\backup\x', 'W:', UNC) == UNC + r'\backup\x'
+
+
+def test_a_trailing_backslash_on_the_unc_does_not_double_up():
+    assert _rewrite(r'W:\backup\x', 'W:', UNC + '\\') == UNC + r'\backup\x'