fix: empty allowed_class skips check

src/tests/analyzers_classdefs_test.py

@@ -35,13 +35,28 @@ def test_inherit_from_allowed_exceptions():
         )
     )
 
-    assert_non_pickable = partial(assert_violation, codes.ALLOWED_BASE_EXCEPTION[0])
+    asset_non_inherit = partial(assert_violation, codes.ALLOWED_BASE_EXCEPTION[0])
     msg_base = codes.ALLOWED_BASE_EXCEPTION[1]
     allowed_msg = ", ".join(allowed_base_exceptions)
 
     violations = analyzer.check(tree, "filename")
 
     assert len(violations) == 2
 
-    assert_non_pickable(msg_base.format("InvalidBase", allowed_msg), 19, 0, violations[0])
-    assert_non_pickable(msg_base.format("MultiInvalidBase", allowed_msg), 23, 0, violations[1])
+    asset_non_inherit(msg_base.format("InvalidBase", allowed_msg), 19, 0, violations[0])
+    asset_non_inherit(msg_base.format("MultiInvalidBase", allowed_msg), 23, 0, violations[1])
+
+
+def test_inherit_from_allowed_exceptions_undefined():
+    tree = read_sample("class_base_allowed")
+    analyzer = analyzers.classdefs.InheritFromBaseAnalyzer(
+        GlobalSettings(
+            include_experimental=False,
+            exclude_dirs=[],
+            ignore_violations=[],
+            allowed_base_exceptions=set(),
+        )
+    )
+
+    violations = analyzer.check(tree, "filename")
+    assert len(violations) == 0

src/tryceratops/analyzers/classdefs.py

@@ -54,11 +54,14 @@ class InheritFromBaseAnalyzer(BaseAnalyzer):
 
     @visit_error_handler
     def visit_ClassDef(self, node: ast.ClassDef) -> t.Any:
+        settings = t.cast(GlobalSettings, self._settings)
+        if not settings.allowed_base_exceptions:
+            return self.generic_visit(node)
+
         is_exc = any([base for base in node.bases if getattr(base, "id", None) == "Exception"])
         if is_exc is False:
             return self.generic_visit(node)
 
-        settings = t.cast(GlobalSettings, self._settings)
         if node.name not in settings.allowed_base_exceptions:
             self._mark_violation(
                 node,