bpo-34776: Fix dataclasses to support __future__ "annotations" mode (#9518)

Lib/test/test_dataclasses.py

@@ -10,6 +10,7 @@ import builtins
 import unittest
 from unittest.mock import Mock
 from typing import ClassVar, Any, List, Union, Tuple, Dict, Generic, TypeVar, Optional
+from typing import get_type_hints
 from collections import deque, OrderedDict, namedtuple
 from functools import total_ordering
 
@@ -2926,6 +2927,17 @@ class TestStringAnnotations(unittest.TestCase):
                     # won't exist on the instance.
                     self.assertNotIn('not_iv4', c.__dict__)
 
+    def test_text_annotations(self):
+        from test import dataclass_textanno
+
+        self.assertEqual(
+            get_type_hints(dataclass_textanno.Bar),
+            {'foo': dataclass_textanno.Foo})
+        self.assertEqual(
+            get_type_hints(dataclass_textanno.Bar.__init__),
+            {'foo': dataclass_textanno.Foo,
+             'return': type(None)})
+
 
 class TestMakeDataclass(unittest.TestCase):
     def test_simple(self):