gh-137463: Update validate_abstract_methods in test_collections.py (#137464)

guilhermeleobas · guilhermeleobas · commit 6c08adbc8edf · 2025-08-07T10:56:03.000-03:00
Update `validate_abstract_methods` in `test_collections.py` The test for missing abstract methods in `validate_abstract_methods` incorrectly attempted to instantiate the generated class `C` with an argument (`C(name)`), which always raises a `TypeError: C() takes no arguments`. Although the test originally passes, it passes for the wrong reason. This change makes the test correctly validate the enforcement of abstract methods in ABCs. (cherry picked from commit 5be8723)
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
@@ -736,7 +736,7 @@ def validate_abstract_methods(self, abc, *names):
             stubs = methodstubs.copy()
             del stubs[name]
             C = type('C', (abc,), stubs)
-            self.assertRaises(TypeError, C, name)
+            self.assertRaises(TypeError, C)
 
     def validate_isinstance(self, abc, name):
         stub = lambda s, *args: 0
@@ -963,7 +963,7 @@ class AnextOnly:
             async def __anext__(self):
                 raise StopAsyncIteration
         self.assertNotIsInstance(AnextOnly(), AsyncIterator)
-        self.validate_abstract_methods(AsyncIterator, '__anext__', '__aiter__')
+        self.validate_abstract_methods(AsyncIterator, '__anext__')
 
     def test_Iterable(self):
         # Check some non-iterables
@@ -1159,8 +1159,8 @@ def test_Iterator(self):
                    ]
         for x in samples:
             self.assertIsInstance(x, Iterator)
-            self.assertTrue(issubclass(type(x), Iterator), repr(type(x)))
-        self.validate_abstract_methods(Iterator, '__next__', '__iter__')
+            self.assertIsSubclass(type(x), Iterator)
+        self.validate_abstract_methods(Iterator, '__next__')
 
         # Issue 10565
         class NextOnly:
@@ -1843,9 +1843,8 @@ def test_Set_hash_matches_frozenset(self):
     def test_Mapping(self):
         for sample in [dict]:
             self.assertIsInstance(sample(), Mapping)
-            self.assertTrue(issubclass(sample, Mapping))
-        self.validate_abstract_methods(Mapping, '__contains__', '__iter__', '__len__',
-            '__getitem__')
+            self.assertIsSubclass(sample, Mapping)
+        self.validate_abstract_methods(Mapping, '__iter__', '__len__', '__getitem__')
         class MyMapping(Mapping):
             def __len__(self):
                 return 0
@@ -1859,8 +1858,8 @@ def __iter__(self):
     def test_MutableMapping(self):
         for sample in [dict]:
             self.assertIsInstance(sample(), MutableMapping)
-            self.assertTrue(issubclass(sample, MutableMapping))
-        self.validate_abstract_methods(MutableMapping, '__contains__', '__iter__', '__len__',
+            self.assertIsSubclass(sample, MutableMapping)
+        self.validate_abstract_methods(MutableMapping, '__iter__', '__len__',
             '__getitem__', '__setitem__', '__delitem__')
 
     def test_MutableMapping_subclass(self):
@@ -1897,10 +1896,9 @@ def test_Sequence(self):
         self.assertIsInstance(range(10), Sequence)
         self.assertTrue(issubclass(range, Sequence))
         self.assertIsInstance(memoryview(b""), Sequence)
-        self.assertTrue(issubclass(memoryview, Sequence))
-        self.assertTrue(issubclass(str, Sequence))
-        self.validate_abstract_methods(Sequence, '__contains__', '__iter__', '__len__',
-            '__getitem__')
+        self.assertIsSubclass(memoryview, Sequence)
+        self.assertIsSubclass(str, Sequence)
+        self.validate_abstract_methods(Sequence, '__len__', '__getitem__')
 
     def test_Sequence_mixins(self):
         class SequenceSubclass(Sequence):
@@ -1974,11 +1972,11 @@ def test_MutableSequence(self):
             self.assertFalse(issubclass(sample, MutableSequence))
         for sample in [list, bytearray, deque]:
             self.assertIsInstance(sample(), MutableSequence)
-            self.assertTrue(issubclass(sample, MutableSequence))
-        self.assertTrue(issubclass(array.array, MutableSequence))
-        self.assertFalse(issubclass(str, MutableSequence))
-        self.validate_abstract_methods(MutableSequence, '__contains__', '__iter__',
-            '__len__', '__getitem__', '__setitem__', '__delitem__', 'insert')
+            self.assertIsSubclass(sample, MutableSequence)
+        self.assertIsSubclass(array.array, MutableSequence)
+        self.assertNotIsSubclass(str, MutableSequence)
+        self.validate_abstract_methods(MutableSequence, '__len__', '__getitem__',
+                                       '__setitem__', '__delitem__', 'insert')
 
     def test_MutableSequence_mixins(self):
         # Test the mixins of MutableSequence by creating a minimal concrete
