Fix evaluation of stringified annotations during namespace inspection (#10347)

Author: Viicos

Diff for: pydantic/_internal/_model_construction.py

@@ -11,7 +11,7 @@
 from abc import ABCMeta
 from functools import lru_cache, partial
 from types import FunctionType
-from typing import Any, Callable, ForwardRef, Generic, Literal, NoReturn
+from typing import Any, Callable, Generic, Literal, NoReturn
 
 import typing_extensions
 from pydantic_core import PydanticUndefined, SchemaSerializer
@@ -30,6 +30,7 @@
 from ._schema_generation_shared import CallbackGetCoreSchemaHandler
 from ._signature import generate_pydantic_signature
 from ._typing_extra import (
+    _make_forward_ref,
     eval_type_backport,
     is_annotated,
     is_classvar,
@@ -436,6 +437,8 @@ def inspect_namespace(  # noqa C901
             is_valid_privateattr_name(ann_name)
             and ann_name not in private_attributes
             and ann_name not in ignored_names
+            # This condition is a false negative when `ann_type` is stringified,
+            # but it is handled in `set_model_fields`:
             and not is_classvar(ann_type)
             and ann_type not in all_ignored_types
             and getattr(ann_type, '__module__', None) != 'functools'
@@ -446,7 +449,9 @@ def inspect_namespace(  # noqa C901
                 frame = sys._getframe(2)
                 if frame is not None:
                     ann_type = eval_type_backport(
-                        ForwardRef(ann_type), globalns=frame.f_globals, localns=frame.f_locals
+                        _make_forward_ref(ann_type, is_argument=False, is_class=True),
+                        globalns=frame.f_globals,
+                        localns=frame.f_locals,
                     )
             if is_annotated(ann_type):
                 _, *metadata = typing_extensions.get_args(ann_type)

Diff for: tests/test_forward_ref.py

@@ -581,10 +581,12 @@ def test_class_var_as_string(create_module):
 
 class Model(BaseModel):
     a: ClassVar[int]
+    _b: ClassVar[int]
 """
     )
 
-    assert module.Model.__class_vars__ == {'a'}
+    assert module.Model.__class_vars__ == {'a', '_b'}
+    assert module.Model.__private_attributes__ == {}
 
 
 def test_json_encoder_str(create_module):