Adds a new heuristic to scripts/audit_exception_handling.py:_try_compliant_pattern
(heuristic B, after heuristic A) that recognizes the canonical lazy-loading
sentinel fallback pattern:
def _resolve(self):
try:
self._cached = getattr(mod, attr_name)
except AttributeError:
sub_mod_name = f'{module_name}.{attr_name}'
try:
self._cached = importlib.import_module(sub_mod_name)
except (ImportError, ModuleNotFoundError):
self._cached = _FiledialogStub()
The heuristic fires when:
- The enclosing function is in LAZY_LOADER_METHOD_NAMES
({_resolve, _load, _get, _try_load}) — the canonical naming
convention for proxy classes that defer a heavy import
- The except body does NOT re-raise
- The except set is in {AttributeError, ImportError, ModuleNotFoundError}
- The except body assigns to a self.<attr> (directly or via nested try)
Sites matching this pattern are classified INTERNAL_COMPLIANT (not
UNCLEAR). The sentinel is a documented graceful-degradation marker
with an 'available: bool = False' flag (or similar) that the UI can
check to detect the stub and offer an alternative path. This is
analogous to the nil-sentinel dataclass (Pattern 1 in error_handling.md).
Per error_handling.md:625-690 (Re-Raise Patterns) and the lazy-loading
pattern guidance, this is NOT silent-sliming. Reclassifies the 2
UNCLEAR sites in src/gui_2.py at L65 and L69 (_LazyModule._resolve).
Pre-Phase 12 baseline: 2 UNCLEAR sites. Post-Phase 12: 0 UNCLEAR.
gui_2.py: V=0, S=0, ?=0, C=56 (was V=0, S=0, ?=2, C=54).
Phase 12 result_migration_gui_2_20260619.
ed
f996aa1066