test(audit_heuristics): add 5 regression tests for dunder raise (Phase 11)

Five regression-guard tests verify the new dunder-method bare-raise
heuristic in scripts/audit_exception_handling.py:_classify_raise:
- test_bare_raise_attribute_error_in_getattr_is_programmer_raise
- test_bare_raise_name_error_in_getattr_is_programmer_raise
- test_bare_raise_in_setattr_is_programmer_raise
- test_bare_raise_in_delattr_is_programmer_raise
- test_bare_raise_in_getattribute_is_programmer_raise

Each test feeds a minimal source sample through the visitor's
_classify_raise and asserts INTERNAL_PROGRAMMER_RAISE. The tests
cover all 4 dunder methods (__getattr__, __getattribute__,
__setattr__, __delattr__) and both programmer-error exception types
(AttributeError, NameError).

Phase 11 result_migration_gui_2_20260619.

tests/test_audit_heuristics.py

@@ -137,3 +137,87 @@ def test_phase7_migrated_sites_no_longer_silent_swallow():
                 f"Phase 7 regression: L{f.line} should not be "
                 f"INTERNAL_SILENT_SWALLOW after migration; got {f.category}"
             )
+
+
+# Phase 11 Task 11.4 - Regression-guard tests for dunder-method bare-raise heuristic.
+# Per Phase 11 spec (INTERNAL_RETHROW classification for dunder methods):
+# - Bare `raise AttributeError(name)` / `raise NameError(name)` in
+#   `__getattr__`, `__getattribute__`, `__setattr__`, `__delattr__` is the
+#   canonical dunder-method programmer-error pattern (per styleguide
+#   "Re-Raise Patterns": bare raises are reserved for programmer errors).
+# - The audit previously classified these as INTERNAL_RETHROW (suspicious);
+#   the heuristic must reclassify them as INTERNAL_PROGRAMMER_RAISE.
+
+DUNDER_RAISE_TESTS = {
+ "__getattr__": "def __getattr__(self, name):\n if name == 'controller':\n  raise AttributeError(name)\n raise AttributeError(name)",
+ "__getattribute__": "def __getattribute__(self, name):\n if name == 'controller':\n  raise AttributeError(name)\n raise AttributeError(name)",
+ "__setattr__": "def __setattr__(self, name, value):\n raise AttributeError(name)",
+ "__delattr__": "def __delattr__(self, name):\n raise AttributeError(name)",
+}
+
+
+def _classify_first_raise(source, func_name):
+ tree = ast.parse(source)
+ for node in ast.walk(tree):
+  if isinstance(node, ast.FunctionDef) and node.name == func_name:
+   visitor = ExceptionVisitor(str(ROOT / "src" / "_test_dummy.py"))
+   visitor._func_stack = [node]
+   for sub in ast.walk(node):
+    if isinstance(sub, ast.Raise) and sub.exc is not None:
+     return visitor._classify_raise(sub)
+ raise AssertionError(f"No raise found in {func_name}")
+
+
+def test_bare_raise_attribute_error_in_getattr_is_programmer_raise():
+ src = DUNDER_RAISE_TESTS["__getattr__"]
+ category, hint = _classify_first_raise(src, "__getattr__")
+ assert category == "INTERNAL_PROGRAMMER_RAISE", (
+  f"Phase 11 regression: bare `raise AttributeError(name)` in __getattr__ "
+  f"should be INTERNAL_PROGRAMMER_RAISE (canonical dunder-method pattern); "
+  f"got {category}. Hint: {hint}"
+ )
+
+
+def test_bare_raise_name_error_in_getattr_is_programmer_raise():
+ src = (
+  "def __getattr__(self, name):\n"
+  " if not hasattr(self, 'x'):\n"
+  "  raise NameError(name)\n"
+  " return self.x"
+ )
+ category, hint = _classify_first_raise(src, "__getattr__")
+ assert category == "INTERNAL_PROGRAMMER_RAISE", (
+  f"Phase 11 regression: bare `raise NameError(name)` in __getattr__ "
+  f"should be INTERNAL_PROGRAMMER_RAISE (canonical dunder-method pattern); "
+  f"got {category}. Hint: {hint}"
+ )
+
+
+def test_bare_raise_in_setattr_is_programmer_raise():
+ src = DUNDER_RAISE_TESTS["__setattr__"]
+ category, hint = _classify_first_raise(src, "__setattr__")
+ assert category == "INTERNAL_PROGRAMMER_RAISE", (
+  f"Phase 11 regression: bare `raise AttributeError` in __setattr__ "
+  f"should be INTERNAL_PROGRAMMER_RAISE (canonical dunder-method pattern); "
+  f"got {category}. Hint: {hint}"
+ )
+
+
+def test_bare_raise_in_delattr_is_programmer_raise():
+ src = DUNDER_RAISE_TESTS["__delattr__"]
+ category, hint = _classify_first_raise(src, "__delattr__")
+ assert category == "INTERNAL_PROGRAMMER_RAISE", (
+  f"Phase 11 regression: bare `raise AttributeError` in __delattr__ "
+  f"should be INTERNAL_PROGRAMMER_RAISE (canonical dunder-method pattern); "
+  f"got {category}. Hint: {hint}"
+ )
+
+
+def test_bare_raise_in_getattribute_is_programmer_raise():
+ src = DUNDER_RAISE_TESTS["__getattribute__"]
+ category, hint = _classify_first_raise(src, "__getattribute__")
+ assert category == "INTERNAL_PROGRAMMER_RAISE", (
+  f"Phase 11 regression: bare `raise AttributeError(name)` in __getattribute__ "
+  f"should be INTERNAL_PROGRAMMER_RAISE (canonical dunder-method pattern); "
+  f"got {category}. Hint: {hint}"
+ )