gh-143959: Make _types optional for test_types

Author: youknowone

Lib/test/test_types.py

@@ -25,6 +25,10 @@
     import _datetime
 except ModuleNotFoundError:
     _datetime = None
+try:
+    import _types
+except ModuleNotFoundError:
+    _types = None
 
 c_types = import_fresh_module('types', fresh=['_types'])
 py_types = import_fresh_module('types', blocked=['_types'])
@@ -43,15 +47,10 @@ def clear_typing_caches():
 
 class TypesTests(unittest.TestCase):
 
-    def test_names(self):
+    def check_types_names(self, module_types, *, c_extension=False):
         c_only_names = {'CapsuleType'}
         ignored = {'new_class', 'resolve_bases', 'prepare_class',
                    'get_original_bases', 'DynamicClassAttribute', 'coroutine'}
-
-        for name in c_types.__all__:
-            if name not in c_only_names | ignored:
-                self.assertIs(getattr(c_types, name), getattr(py_types, name))
-
         all_names = ignored | {
             'AsyncGeneratorType', 'BuiltinFunctionType', 'BuiltinMethodType',
             'CapsuleType', 'CellType', 'ClassMethodDescriptorType', 'CodeType',
@@ -63,8 +62,24 @@ def test_names(self):
             'ModuleType', 'NoneType', 'NotImplementedType', 'SimpleNamespace',
             'TracebackType', 'UnionType', 'WrapperDescriptorType',
         }
-        self.assertEqual(all_names, set(c_types.__all__))
-        self.assertEqual(all_names - c_only_names, set(py_types.__all__))
+        expected = all_names if c_extension else all_names - c_only_names
+        self.assertEqual(expected, set(module_types.__all__))
+
+    @unittest.skipUnless(_types, "requires C _types module")
+    def test_c_types_names(self):
+        self.check_types_names(c_types, c_extension=True)
+
+    def test_py_types_names(self):
+        self.check_types_names(py_types, c_extension=False)
+
+    @unittest.skipUnless(_types, "requires C _types module")
+    def test_types_names_consistency(self):
+        c_only_names = {'CapsuleType'}
+        ignored = {'new_class', 'resolve_bases', 'prepare_class',
+                   'get_original_bases', 'DynamicClassAttribute', 'coroutine'}
+        for name in c_types.__all__:
+            if name not in c_only_names | ignored:
+                self.assertIs(getattr(c_types, name), getattr(py_types, name))
 
     def test_truth_values(self):
         if None: self.fail('None is true instead of false')