Fix issue with ClassVar parsing (#3403)

* Fix issue with ClassVar parsing

* Fix lint error

* Simplify test

* Fix condition and test

changes/3401-uriyyo.md

@@ -0,0 +1 @@
+Fix issue when pydantic fail to parse `typing.ClassVar` string type annotation.

pydantic/typing.py

@@ -332,7 +332,9 @@ def resolve_annotations(raw_annotations: Dict[str, Type[Any]], module_name: Opti
     annotations = {}
     for name, value in raw_annotations.items():
         if isinstance(value, str):
-            if sys.version_info >= (3, 7):
+            if (3, 10) > sys.version_info >= (3, 9, 8) or sys.version_info >= (3, 10, 1):
+                value = ForwardRef(value, is_argument=False, is_class=True)
+            elif sys.version_info >= (3, 7):
                 value = ForwardRef(value, is_argument=False)
             else:
                 value = ForwardRef(value)

tests/test_forward_ref.py

@@ -519,3 +519,20 @@ def test_nested_forward_ref():
     NestedTuple.update_forward_refs()
     obj = NestedTuple.parse_obj({'x': ('1', {'x': ('2', {'x': ('3', None)})})})
     assert obj.dict() == {'x': (1, {'x': (2, {'x': (3, None)})})}
+
+
+@skip_pre_37
+def test_class_var_as_string(create_module):
+    module = create_module(
+        # language=Python
+        """
+from __future__ import annotations
+from typing import ClassVar
+from pydantic import BaseModel
+
+class Model(BaseModel):
+    a: ClassVar[int]
+"""
+    )
+
+    assert module.Model.__class_vars__ == {'a'}