Add tests for type hint resolution

rest_framework_dataclasses/typing_utils.py

@@ -56,8 +56,10 @@ def get_resolved_type_hints(tp: type) -> typing.Dict[str, type]:
  Resolving the type hints means converting any stringified type hint into an actual type object. These can come from
  either forward references (PEP 484), or postponed evaluation (PEP 563).
  """
- # typing.get_type_hints() does the heavy lifting for us, except when using PEP 585 generic types that contain a
- # stringified type hint (see https://bugs.python.org/issue41370)
+ # typing.get_type_hints() does the heavy lifting for us, except:
+ # - when using PEP 585 generic types that contain a stringified type hint, on Python 3.9 and 3.10. See
+ # https://bugs.python.org/issue41370
+ # - when using PEP 695 type aliases
  def _resolve_type(context_type: type, resolve_type: typing.Union[str, type]) -> type:
  if isinstance(resolve_type, str):
  globalsns = sys.modules[context_type.__module__].__dict__

tests/test_typing_utils.py

@@ -1,3 +1,4 @@
+import types as types_module
 import typing
 import unittest
 import sys
@@ -11,6 +12,41 @@ def assertAnyTypeEquivalent(self, tp: type):
  # 3.7 and 3.8). It's essentially the same, and we strip the typevar before usage anyway.
  self.assertTrue(tp is typing.Any or (isinstance(tp, typing.TypeVar) and len(tp.__constraints__) == 0))
 
+ def test_resolve(self):
+ class Hinted:
+ a: str
+ b: 'str'
+
+ hints = typing_utils.get_resolved_type_hints(Hinted)
+ self.assertEqual(hints['a'], str)
+ self.assertEqual(hints['b'], str)
+
+ @unittest.skipIf(sys.version_info < (3, 9, 0), 'Python 3.9 required')
+ def test_resolve_pep585(self):
+ class Hinted:
+ a: list[str]
+ b: list['str']
+
+ hints = typing_utils.get_resolved_type_hints(Hinted)
+ self.assertEqual(hints['a'], types_module.GenericAlias(list, (str, )))
+ self.assertEqual(hints['b'], types_module.GenericAlias(list, (str, )))
+
+ @unittest.skipif(sys.version_info < (3, 12, 0), 'Python 3.12 required')
+ def test_resolve_pep695(self):
+ type Str = str
+ type StrList = list[str]
+ type GenericList = list[T]
+
+ class Hinted:
+ a: Str
+ b: StrList
+ c: GenericList
+
+ hints = typing_utils.get_resolved_type_hints(Hinted)
+ self.assertEqual(hints['a'], str)
+ self.assertEqual(hints['a'], list[str])
+ self.assertEqual(hints['a'], list[T])
+
  def test_iterable(self):
  self.assertTrue(typing_utils.is_iterable_type(typing.Iterable[str]))
  self.assertTrue(typing_utils.is_iterable_type(typing.Collection[str]))