Add test for re-evaluation of ForwardRef objects

Author: dr-carlos

Lib/test/test_annotationlib.py

@@ -1,30 +1,25 @@
 """Tests for the annotations module."""
 
-import textwrap
-import annotationlib
 import builtins
 import collections
 import functools
 import itertools
 import pickle
-from string.templatelib import Template
+import textwrap
 import typing
 import unittest
-from annotationlib import (
-    Format,
-    ForwardRef,
-    get_annotations,
-    annotations_to_string,
-    type_repr,
-)
-from typing import Unpack, get_type_hints, List, Union
-
+from string.templatelib import Template
 from test import support
 from test.support import import_helper
-from test.test_inspect import inspect_stock_annotations
-from test.test_inspect import inspect_stringized_annotations
-from test.test_inspect import inspect_stringized_annotations_2
-from test.test_inspect import inspect_stringized_annotations_pep695
+from test.test_inspect import (inspect_stock_annotations,
+                               inspect_stringized_annotations,
+                               inspect_stringized_annotations_2,
+                               inspect_stringized_annotations_pep695)
+from typing import List, Union, Unpack, get_type_hints
+
+import annotationlib
+from annotationlib import (Format, ForwardRef, annotations_to_string,
+                           get_annotations, type_repr)
 
 
 def times_three(fn):
@@ -1683,6 +1678,28 @@ def test_fwdref_invalid_syntax(self):
         with self.assertRaises(SyntaxError):
             fr.evaluate()
 
+    def test_re_evaluate(self):
+        class C:
+            x: alias
+
+        evaluated = get_annotations(C, format=Format.FORWARDREF)["x"].evaluate(format=Format.FORWARDREF)
+        alias = int
+        self.assertIs(evaluated.evaluate(), int)
+
+        del alias
+        evaluated = get_annotations(C, format=Format.FORWARDREF)["x"].evaluate(format=Format.FORWARDREF)
+        with self.assertRaises(NameError):
+            evaluated.evaluate()
+
+        class C:
+            x: alias2
+
+        evaluated = get_annotations(C, format=Format.FORWARDREF)["x"].evaluate(format=Format.FORWARDREF)
+        global alias2
+        alias2 = str
+        self.assertIs(evaluated.evaluate(), str)
+
+
 
 class TestAnnotationLib(unittest.TestCase):
     def test__all__(self):