1 files changed, 22 insertions, 18 deletions

diff --git a/Lib/test/_test_embed_structseq.py b/Lib/test/_test_embed_structseq.py
index 868f9f8..834daa4 100644
--- a/Lib/test/_test_embed_structseq.py
+++ b/Lib/test/_test_embed_structseq.py
@@ -1,27 +1,31 @@
 import sys
 import types
-import unittest
 
+# Note: This test file can't import `unittest` since the runtime can't
+# currently guarantee that it will not leak memory. Doing so will mark
+# the test as passing but with reference leaks. This can safely import
+# the `unittest` library once there's a strict guarantee of no leaks
+# during runtime shutdown.
 
 # bpo-46417: Test that structseq types used by the sys module are still
 # valid when Py_Finalize()/Py_Initialize() are called multiple times.
-class TestStructSeq(unittest.TestCase):
+class TestStructSeq:
     # test PyTypeObject members
-    def check_structseq(self, obj_type):
+    def _check_structseq(self, obj_type):
         # ob_refcnt
-        self.assertGreaterEqual(sys.getrefcount(obj_type), 1)
+        assert sys.getrefcount(obj_type) > 1
         # tp_base
-        self.assertTrue(issubclass(obj_type, tuple))
+        assert issubclass(obj_type, tuple)
         # tp_bases
-        self.assertEqual(obj_type.__bases__, (tuple,))
+        assert obj_type.__bases__ == (tuple,)
         # tp_dict
-        self.assertIsInstance(obj_type.__dict__, types.MappingProxyType)
+        assert isinstance(obj_type.__dict__, types.MappingProxyType)
         # tp_mro
-        self.assertEqual(obj_type.__mro__, (obj_type, tuple, object))
+        assert obj_type.__mro__ == (obj_type, tuple, object)
         # tp_name
-        self.assertIsInstance(type.__name__, str)
+        assert isinstance(type.__name__, str)
         # tp_subclasses
-        self.assertEqual(obj_type.__subclasses__(), [])
+        assert obj_type.__subclasses__() == []
 
     def test_sys_attrs(self):
         for attr_name in (
@@ -32,23 +36,23 @@ class TestStructSeq(unittest.TestCase):
             'thread_info',    # ThreadInfoType
             'version_info',   # VersionInfoType
         ):
-            with self.subTest(attr=attr_name):
-                attr = getattr(sys, attr_name)
-                self.check_structseq(type(attr))
+            attr = getattr(sys, attr_name)
+            self._check_structseq(type(attr))
 
     def test_sys_funcs(self):
         func_names = ['get_asyncgen_hooks']  # AsyncGenHooksType
         if hasattr(sys, 'getwindowsversion'):
             func_names.append('getwindowsversion')  # WindowsVersionType
         for func_name in func_names:
-            with self.subTest(func=func_name):
-                func = getattr(sys, func_name)
-                obj = func()
-                self.check_structseq(type(obj))
+            func = getattr(sys, func_name)
+            obj = func()
+            self._check_structseq(type(obj))
 
 
 try:
-    unittest.main()
+    tests = TestStructSeq()
+    tests.test_sys_attrs()
+    tests.test_sys_funcs()
 except SystemExit as exc:
     if exc.args[0] != 0:
         raise