[3.12] gh-107178: Add the C API tests for the Abstract Objects Layer (GH-107179) (#107728)

Cover all the Mapping Protocol, almost all the Sequence Protocol
(except PySequence_Fast) and a part of the Object Protocol.

Move existing tests to Lib/test/test_capi/test_abstract.py and
Modules/_testcapi/abstract.c.

Add also tests for PyDict C API..
(cherry picked from commit 16c9415fba4972743f1944ebc44946e475e68bc4)

13 files changed, 1955 insertions, 299 deletions

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 7c62b72..afd506f 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -1354,7 +1354,7 @@ class ByteArrayTest(BaseBytesTest, unittest.TestCase):
             except ValueError:
                 pass
             try:
-                setitem(b, 0, None)
+                setitem(b, 0, object())
                 self.fail("Didn't raise TypeError")
             except TypeError:
                 pass
diff --git a/Lib/test/test_capi/test_abstract.py b/Lib/test/test_capi/test_abstract.py
new file mode 100644
index 0000000..116edd8
--- /dev/null
+++ b/Lib/test/test_capi/test_abstract.py
@@ -0,0 +1,694 @@
+import unittest
+import sys
+from collections import OrderedDict
+from test import support
+from test.support import import_helper
+import _testcapi
+
+
+NULL = None
+
+class TestObject:
+    @property
+    def evil(self):
+        raise RuntimeError('do not get evil')
+    @evil.setter
+    def evil(self, value):
+        raise RuntimeError('do not set evil')
+    @evil.deleter
+    def evil(self):
+        raise RuntimeError('do not del evil')
+
+class ProxyGetItem:
+    def __init__(self, obj):
+        self.obj = obj
+    def __getitem__(self, key):
+        return self.obj[key]
+
+class ProxySetItem:
+    def __init__(self, obj):
+        self.obj = obj
+    def __setitem__(self, key, value):
+        self.obj[key] = value
+
+class ProxyDelItem:
+    def __init__(self, obj):
+        self.obj = obj
+    def __delitem__(self, key):
+        del self.obj[key]
+
+def gen():
+    yield 'a'
+    yield 'b'
+    yield 'c'
+
+
+class CAPITest(unittest.TestCase):
+
+    def test_object_getattr(self):
+        xgetattr = _testcapi.object_getattr
+        obj = TestObject()
+        obj.a = 11
+        setattr(obj, '\U0001f40d', 22)
+        self.assertEqual(xgetattr(obj, 'a'), 11)
+        self.assertRaises(AttributeError, xgetattr, obj, 'b')
+        self.assertEqual(xgetattr(obj, '\U0001f40d'), 22)
+
+        self.assertRaises(RuntimeError, xgetattr, obj, 'evil')
+        self.assertRaises(TypeError, xgetattr, obj, 1)
+        # CRASHES xgetattr(obj, NULL)
+        # CRASHES xgetattr(NULL, 'a')
+
+    def test_object_getattrstring(self):
+        getattrstring = _testcapi.object_getattrstring
+        obj = TestObject()
+        obj.a = 11
+        setattr(obj, '\U0001f40d', 22)
+        self.assertEqual(getattrstring(obj, b'a'), 11)
+        self.assertRaises(AttributeError, getattrstring, obj, b'b')
+        self.assertEqual(getattrstring(obj, '\U0001f40d'.encode()), 22)
+
+        self.assertRaises(RuntimeError, getattrstring, obj, b'evil')
+        self.assertRaises(UnicodeDecodeError, getattrstring, obj, b'\xff')
+        # CRASHES getattrstring(obj, NULL)
+        # CRASHES getattrstring(NULL, b'a')
+
+    def test_object_hasattr(self):
+        xhasattr = _testcapi.object_hasattr
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        self.assertTrue(xhasattr(obj, 'a'))
+        self.assertFalse(xhasattr(obj, 'b'))
+        self.assertTrue(xhasattr(obj, '\U0001f40d'))
+
+        self.assertFalse(xhasattr(obj, 'evil'))
+        self.assertFalse(xhasattr(obj, 1))
+        # CRASHES xhasattr(obj, NULL)
+        # CRASHES xhasattr(NULL, 'a')
+
+    def test_object_hasattrstring(self):
+        hasattrstring = _testcapi.object_hasattrstring
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        self.assertTrue(hasattrstring(obj, b'a'))
+        self.assertFalse(hasattrstring(obj, b'b'))
+        self.assertTrue(hasattrstring(obj, '\U0001f40d'.encode()))
+
+        self.assertFalse(hasattrstring(obj, b'evil'))
+        self.assertFalse(hasattrstring(obj, b'\xff'))
+        # CRASHES hasattrstring(obj, NULL)
+        # CRASHES hasattrstring(NULL, b'a')
+
+    def test_object_setattr(self):
+        xsetattr = _testcapi.object_setattr
+        obj = TestObject()
+        xsetattr(obj, 'a', 5)
+        self.assertEqual(obj.a, 5)
+        xsetattr(obj, '\U0001f40d', 8)
+        self.assertEqual(getattr(obj, '\U0001f40d'), 8)
+
+        # PyObject_SetAttr(obj, attr_name, NULL) removes the attribute
+        xsetattr(obj, 'a', NULL)
+        self.assertFalse(hasattr(obj, 'a'))
+        self.assertRaises(AttributeError, xsetattr, obj, 'b', NULL)
+        self.assertRaises(RuntimeError, xsetattr, obj, 'evil', NULL)
+
+        self.assertRaises(RuntimeError, xsetattr, obj, 'evil', 'good')
+        self.assertRaises(AttributeError, xsetattr, 42, 'a', 5)
+        self.assertRaises(TypeError, xsetattr, obj, 1, 5)
+        # CRASHES xsetattr(obj, NULL, 5)
+        # CRASHES xsetattr(NULL, 'a', 5)
+
+    def test_object_setattrstring(self):
+        setattrstring = _testcapi.object_setattrstring
+        obj = TestObject()
+        setattrstring(obj, b'a', 5)
+        self.assertEqual(obj.a, 5)
+        setattrstring(obj, '\U0001f40d'.encode(), 8)
+        self.assertEqual(getattr(obj, '\U0001f40d'), 8)
+
+        # PyObject_SetAttrString(obj, attr_name, NULL) removes the attribute
+        setattrstring(obj, b'a', NULL)
+        self.assertFalse(hasattr(obj, 'a'))
+        self.assertRaises(AttributeError, setattrstring, obj, b'b', NULL)
+        self.assertRaises(RuntimeError, setattrstring, obj, b'evil', NULL)
+
+        self.assertRaises(RuntimeError, setattrstring, obj, b'evil', 'good')
+        self.assertRaises(AttributeError, setattrstring, 42, b'a', 5)
+        self.assertRaises(TypeError, setattrstring, obj, 1, 5)
+        self.assertRaises(UnicodeDecodeError, setattrstring, obj, b'\xff', 5)
+        # CRASHES setattrstring(obj, NULL, 5)
+        # CRASHES setattrstring(NULL, b'a', 5)
+
+    def test_object_delattr(self):
+        xdelattr = _testcapi.object_delattr
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        xdelattr(obj, 'a')
+        self.assertFalse(hasattr(obj, 'a'))
+        self.assertRaises(AttributeError, xdelattr, obj, 'b')
+        xdelattr(obj, '\U0001f40d')
+        self.assertFalse(hasattr(obj, '\U0001f40d'))
+
+        self.assertRaises(AttributeError, xdelattr, 42, 'numerator')
+        self.assertRaises(RuntimeError, xdelattr, obj, 'evil')
+        self.assertRaises(TypeError, xdelattr, obj, 1)
+        # CRASHES xdelattr(obj, NULL)
+        # CRASHES xdelattr(NULL, 'a')
+
+    def test_object_delattrstring(self):
+        delattrstring = _testcapi.object_delattrstring
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        delattrstring(obj, b'a')
+        self.assertFalse(hasattr(obj, 'a'))
+        self.assertRaises(AttributeError, delattrstring, obj, b'b')
+        delattrstring(obj, '\U0001f40d'.encode())
+        self.assertFalse(hasattr(obj, '\U0001f40d'))
+
+        self.assertRaises(AttributeError, delattrstring, 42, b'numerator')
+        self.assertRaises(RuntimeError, delattrstring, obj, b'evil')
+        self.assertRaises(UnicodeDecodeError, delattrstring, obj, b'\xff')
+        # CRASHES delattrstring(obj, NULL)
+        # CRASHES delattrstring(NULL, b'a')
+
+
+    def test_mapping_check(self):
+        check = _testcapi.mapping_check
+        self.assertTrue(check({1: 2}))
+        self.assertTrue(check([1, 2]))
+        self.assertTrue(check((1, 2)))
+        self.assertTrue(check('abc'))
+        self.assertTrue(check(b'abc'))
+        self.assertFalse(check(42))
+        self.assertFalse(check(object()))
+        self.assertFalse(check(NULL))
+
+    def test_mapping_size(self):
+        for size in _testcapi.mapping_size, _testcapi.mapping_length:
+            self.assertEqual(size({1: 2}), 1)
+            self.assertEqual(size([1, 2]), 2)
+            self.assertEqual(size((1, 2)), 2)
+            self.assertEqual(size('abc'), 3)
+            self.assertEqual(size(b'abc'), 3)
+
+            self.assertRaises(TypeError, size, 42)
+            self.assertRaises(TypeError, size, object())
+            self.assertRaises(SystemError, size, NULL)
+
+    def test_object_getitem(self):
+        getitem = _testcapi.object_getitem
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertEqual(getitem(dct, 'a'), 1)
+        self.assertRaises(KeyError, getitem, dct, 'b')
+        self.assertEqual(getitem(dct, '\U0001f40d'), 2)
+
+        dct2 = ProxyGetItem(dct)
+        self.assertEqual(getitem(dct2, 'a'), 1)
+        self.assertRaises(KeyError, getitem, dct2, 'b')
+
+        self.assertEqual(getitem(['a', 'b', 'c'], 1), 'b')
+
+        self.assertRaises(TypeError, getitem, 42, 'a')
+        self.assertRaises(TypeError, getitem, {}, [])  # unhashable
+        self.assertRaises(SystemError, getitem, {}, NULL)
+        self.assertRaises(IndexError, getitem, [], 1)
+        self.assertRaises(TypeError, getitem, [], 'a')
+        self.assertRaises(SystemError, getitem, NULL, 'a')
+
+    def test_mapping_getitemstring(self):
+        getitemstring = _testcapi.mapping_getitemstring
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertEqual(getitemstring(dct, b'a'), 1)
+        self.assertRaises(KeyError, getitemstring, dct, b'b')
+        self.assertEqual(getitemstring(dct, '\U0001f40d'.encode()), 2)
+
+        dct2 = ProxyGetItem(dct)
+        self.assertEqual(getitemstring(dct2, b'a'), 1)
+        self.assertRaises(KeyError, getitemstring, dct2, b'b')
+
+        self.assertRaises(TypeError, getitemstring, 42, b'a')
+        self.assertRaises(UnicodeDecodeError, getitemstring, {}, b'\xff')
+        self.assertRaises(SystemError, getitemstring, {}, NULL)
+        self.assertRaises(TypeError, getitemstring, [], b'a')
+        self.assertRaises(SystemError, getitemstring, NULL, b'a')
+
+    def test_mapping_haskey(self):
+        haskey = _testcapi.mapping_haskey
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertTrue(haskey(dct, 'a'))
+        self.assertFalse(haskey(dct, 'b'))
+        self.assertTrue(haskey(dct, '\U0001f40d'))
+
+        dct2 = ProxyGetItem(dct)
+        self.assertTrue(haskey(dct2, 'a'))
+        self.assertFalse(haskey(dct2, 'b'))
+
+        self.assertTrue(haskey(['a', 'b', 'c'], 1))
+
+        self.assertFalse(haskey(42, 'a'))
+        self.assertFalse(haskey({}, []))  # unhashable
+        self.assertFalse(haskey({}, NULL))
+        self.assertFalse(haskey([], 1))
+        self.assertFalse(haskey([], 'a'))
+        self.assertFalse(haskey(NULL, 'a'))
+
+    def test_mapping_haskeystring(self):
+        haskeystring = _testcapi.mapping_haskeystring
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertTrue(haskeystring(dct, b'a'))
+        self.assertFalse(haskeystring(dct, b'b'))
+        self.assertTrue(haskeystring(dct, '\U0001f40d'.encode()))
+
+        dct2 = ProxyGetItem(dct)
+        self.assertTrue(haskeystring(dct2, b'a'))
+        self.assertFalse(haskeystring(dct2, b'b'))
+
+        self.assertFalse(haskeystring(42, b'a'))
+        self.assertFalse(haskeystring({}, b'\xff'))
+        self.assertFalse(haskeystring({}, NULL))
+        self.assertFalse(haskeystring([], b'a'))
+        self.assertFalse(haskeystring(NULL, b'a'))
+
+    def test_object_setitem(self):
+        setitem = _testcapi.object_setitem
+        dct = {}
+        setitem(dct, 'a', 5)
+        self.assertEqual(dct, {'a': 5})
+        setitem(dct, '\U0001f40d', 8)
+        self.assertEqual(dct, {'a': 5, '\U0001f40d': 8})
+
+        dct = {}
+        dct2 = ProxySetItem(dct)
+        setitem(dct2, 'a', 5)
+        self.assertEqual(dct, {'a': 5})
+
+        lst = ['a', 'b', 'c']
+        setitem(lst, 1, 'x')
+        self.assertEqual(lst, ['a', 'x', 'c'])
+
+        self.assertRaises(TypeError, setitem, 42, 'a', 5)
+        self.assertRaises(TypeError, setitem, {}, [], 5)  # unhashable
+        self.assertRaises(SystemError, setitem, {}, NULL, 5)
+        self.assertRaises(SystemError, setitem, {}, 'a', NULL)
+        self.assertRaises(IndexError, setitem, [], 1, 5)
+        self.assertRaises(TypeError, setitem, [], 'a', 5)
+        self.assertRaises(TypeError, setitem, (), 1, 5)
+        self.assertRaises(SystemError, setitem, NULL, 'a', 5)
+
+    def test_mapping_setitemstring(self):
+        setitemstring = _testcapi.mapping_setitemstring
+        dct = {}
+        setitemstring(dct, b'a', 5)
+        self.assertEqual(dct, {'a': 5})
+        setitemstring(dct, '\U0001f40d'.encode(), 8)
+        self.assertEqual(dct, {'a': 5, '\U0001f40d': 8})
+
+        dct = {}
+        dct2 = ProxySetItem(dct)
+        setitemstring(dct2, b'a', 5)
+        self.assertEqual(dct, {'a': 5})
+
+        self.assertRaises(TypeError, setitemstring, 42, b'a', 5)
+        self.assertRaises(UnicodeDecodeError, setitemstring, {}, b'\xff', 5)
+        self.assertRaises(SystemError, setitemstring, {}, NULL, 5)
+        self.assertRaises(SystemError, setitemstring, {}, b'a', NULL)
+        self.assertRaises(TypeError, setitemstring, [], b'a', 5)
+        self.assertRaises(SystemError, setitemstring, NULL, b'a', 5)
+
+    def test_object_delitem(self):
+        for delitem in _testcapi.object_delitem, _testcapi.mapping_delitem:
+            dct = {'a': 1, 'c': 2, '\U0001f40d': 3}
+            delitem(dct, 'a')
+            self.assertEqual(dct, {'c': 2, '\U0001f40d': 3})
+            self.assertRaises(KeyError, delitem, dct, 'b')
+            delitem(dct, '\U0001f40d')
+            self.assertEqual(dct, {'c': 2})
+
+            dct = {'a': 1, 'c': 2}
+            dct2 = ProxyDelItem(dct)
+            delitem(dct2, 'a')
+            self.assertEqual(dct, {'c': 2})
+            self.assertRaises(KeyError, delitem, dct2, 'b')
+
+            lst = ['a', 'b', 'c']
+            delitem(lst, 1)
+            self.assertEqual(lst, ['a', 'c'])
+
+            self.assertRaises(TypeError, delitem, 42, 'a')
+            self.assertRaises(TypeError, delitem, {}, [])  # unhashable
+            self.assertRaises(SystemError, delitem, {}, NULL)
+            self.assertRaises(IndexError, delitem, [], 1)
+            self.assertRaises(TypeError, delitem, [], 'a')
+            self.assertRaises(SystemError, delitem, NULL, 'a')
+
+    def test_mapping_delitemstring(self):
+        delitemstring = _testcapi.mapping_delitemstring
+        dct = {'a': 1, 'c': 2, '\U0001f40d': 3}
+        delitemstring(dct, b'a')
+        self.assertEqual(dct, {'c': 2, '\U0001f40d': 3})
+        self.assertRaises(KeyError, delitemstring, dct, b'b')
+        delitemstring(dct, '\U0001f40d'.encode())
+        self.assertEqual(dct, {'c': 2})
+
+        dct = {'a': 1, 'c': 2}
+        dct2 = ProxyDelItem(dct)
+        delitemstring(dct2, b'a')
+        self.assertEqual(dct, {'c': 2})
+        self.assertRaises(KeyError, delitemstring, dct2, b'b')
+
+        self.assertRaises(TypeError, delitemstring, 42, b'a')
+        self.assertRaises(UnicodeDecodeError, delitemstring, {}, b'\xff')
+        self.assertRaises(SystemError, delitemstring, {}, NULL)
+        self.assertRaises(TypeError, delitemstring, [], b'a')
+        self.assertRaises(SystemError, delitemstring, NULL, b'a')
+
+    def test_mapping_keys_valuesitems(self):
+        class Mapping1(dict):
+            def keys(self):
+                return list(super().keys())
+            def values(self):
+                return list(super().values())
+            def items(self):
+                return list(super().items())
+        class Mapping2(dict):
+            def keys(self):
+                return tuple(super().keys())
+            def values(self):
+                return tuple(super().values())
+            def items(self):
+                return tuple(super().items())
+        dict_obj = {'foo': 1, 'bar': 2, 'spam': 3}
+
+        for mapping in [{}, OrderedDict(), Mapping1(), Mapping2(),
+                        dict_obj, OrderedDict(dict_obj),
+                        Mapping1(dict_obj), Mapping2(dict_obj)]:
+            self.assertListEqual(_testcapi.mapping_keys(mapping),
+                                 list(mapping.keys()))
+            self.assertListEqual(_testcapi.mapping_values(mapping),
+                                 list(mapping.values()))
+            self.assertListEqual(_testcapi.mapping_items(mapping),
+                                 list(mapping.items()))
+
+    def test_mapping_keys_valuesitems_bad_arg(self):
+        self.assertRaises(AttributeError, _testcapi.mapping_keys, object())
+        self.assertRaises(AttributeError, _testcapi.mapping_values, object())
+        self.assertRaises(AttributeError, _testcapi.mapping_items, object())
+        self.assertRaises(AttributeError, _testcapi.mapping_keys, [])
+        self.assertRaises(AttributeError, _testcapi.mapping_values, [])
+        self.assertRaises(AttributeError, _testcapi.mapping_items, [])
+        self.assertRaises(SystemError, _testcapi.mapping_keys, NULL)
+        self.assertRaises(SystemError, _testcapi.mapping_values, NULL)
+        self.assertRaises(SystemError, _testcapi.mapping_items, NULL)
+
+        class BadMapping:
+            def keys(self):
+                return None
+            def values(self):
+                return None
+            def items(self):
+                return None
+        bad_mapping = BadMapping()
+        self.assertRaises(TypeError, _testcapi.mapping_keys, bad_mapping)
+        self.assertRaises(TypeError, _testcapi.mapping_values, bad_mapping)
+        self.assertRaises(TypeError, _testcapi.mapping_items, bad_mapping)
+
+    def test_sequence_check(self):
+        check = _testcapi.sequence_check
+        self.assertFalse(check({1: 2}))
+        self.assertTrue(check([1, 2]))
+        self.assertTrue(check((1, 2)))
+        self.assertTrue(check('abc'))
+        self.assertTrue(check(b'abc'))
+        self.assertFalse(check(42))
+        self.assertFalse(check(object()))
+        # CRASHES check(NULL)
+
+    def test_sequence_size(self):
+        for size in _testcapi.sequence_size, _testcapi.sequence_length:
+            self.assertEqual(size([1, 2]), 2)
+            self.assertEqual(size((1, 2)), 2)
+            self.assertEqual(size('abc'), 3)
+            self.assertEqual(size(b'abc'), 3)
+
+            self.assertRaises(TypeError, size, {})
+            self.assertRaises(TypeError, size, 42)
+            self.assertRaises(TypeError, size, object())
+            self.assertRaises(SystemError, size, NULL)
+
+    def test_sequence_getitem(self):
+        getitem = _testcapi.sequence_getitem
+        lst = ['a', 'b', 'c']
+        self.assertEqual(getitem(lst, 1), 'b')
+        self.assertEqual(getitem(lst, -1), 'c')
+        self.assertRaises(IndexError, getitem, lst, 3)
+
+        self.assertRaises(TypeError, getitem, 42, 1)
+        self.assertRaises(TypeError, getitem, {}, 1)
+        self.assertRaises(SystemError, getitem, NULL, 1)
+
+    def test_sequence_concat(self):
+        concat = _testcapi.sequence_concat
+        self.assertEqual(concat(['a', 'b'], [1, 2]), ['a', 'b', 1, 2])
+        self.assertEqual(concat(('a', 'b'), (1, 2)), ('a', 'b', 1, 2))
+
+        self.assertRaises(TypeError, concat, [], ())
+        self.assertRaises(TypeError, concat, (), [])
+        self.assertRaises(TypeError, concat, [], 42)
+        self.assertRaises(TypeError, concat, 42, [])
+        self.assertRaises(TypeError, concat, 42, 43)
+        self.assertRaises(SystemError, concat, [], NULL)
+        self.assertRaises(SystemError, concat, NULL, [])
+
+    def test_sequence_repeat(self):
+        repeat = _testcapi.sequence_repeat
+        self.assertEqual(repeat(['a', 'b'], 2), ['a', 'b', 'a', 'b'])
+        self.assertEqual(repeat(('a', 'b'), 2), ('a', 'b', 'a', 'b'))
+        self.assertEqual(repeat(['a', 'b'], 0), [])
+        self.assertEqual(repeat(['a', 'b'], -1), [])
+
+        self.assertRaises(TypeError, repeat, set(), 2)
+        self.assertRaises(TypeError, repeat, 42, 2)
+        self.assertRaises(SystemError, repeat, NULL, 2)
+
+    def test_sequence_inplaceconcat(self):
+        inplaceconcat = _testcapi.sequence_inplaceconcat
+        lst = ['a', 'b']
+        res = inplaceconcat(lst, [1, 2])
+        self.assertEqual(res, ['a', 'b', 1, 2])
+        self.assertIs(res, lst)
+        lst = ['a', 'b']
+        res = inplaceconcat(lst, (1, 2))
+        self.assertEqual(res, ['a', 'b', 1, 2])
+        self.assertIs(res, lst)
+        self.assertEqual(inplaceconcat(('a', 'b'), (1, 2)), ('a', 'b', 1, 2))
+
+        self.assertRaises(TypeError, inplaceconcat, (), [])
+        self.assertRaises(TypeError, inplaceconcat, [], 42)
+        self.assertRaises(TypeError, inplaceconcat, 42, [])
+        self.assertRaises(TypeError, inplaceconcat, 42, 43)
+        self.assertRaises(SystemError, inplaceconcat, [], NULL)
+        self.assertRaises(SystemError, inplaceconcat, NULL, [])
+
+    def test_sequence_inplacerepeat(self):
+        inplacerepeat = _testcapi.sequence_inplacerepeat
+        lst = ['a', 'b']
+        res = inplacerepeat(lst, 2)
+        self.assertEqual(res, ['a', 'b', 'a', 'b'])
+        self.assertIs(res, lst)
+        self.assertEqual(inplacerepeat(('a', 'b'), 2), ('a', 'b', 'a', 'b'))
+        self.assertEqual(inplacerepeat(['a', 'b'], 0), [])
+        self.assertEqual(inplacerepeat(['a', 'b'], -1), [])
+
+        self.assertRaises(TypeError, inplacerepeat, set(), 2)
+        self.assertRaises(TypeError, inplacerepeat, 42, 2)
+        self.assertRaises(SystemError, inplacerepeat, NULL, 2)
+
+    def test_sequence_setitem(self):
+        setitem = _testcapi.sequence_setitem
+        lst = ['a', 'b', 'c']
+        setitem(lst, 1, 'x')
+        self.assertEqual(lst, ['a', 'x', 'c'])
+        setitem(lst, -1, 'y')
+        self.assertEqual(lst, ['a', 'x', 'y'])
+
+        setitem(lst, 0, NULL)
+        self.assertEqual(lst, ['x', 'y'])
+        self.assertRaises(IndexError, setitem, lst, 3, 'x')
+
+        self.assertRaises(TypeError, setitem, 42, 1, 'x')
+        self.assertRaises(TypeError, setitem, {}, 1, 'x')
+        self.assertRaises(SystemError, setitem, NULL, 1, 'x')
+
+    def test_sequence_delitem(self):
+        delitem = _testcapi.sequence_delitem
+        lst = ['a', 'b', 'c']
+        delitem(lst, 1)
+        self.assertEqual(lst, ['a', 'c'])
+        delitem(lst, -1)
+        self.assertEqual(lst, ['a'])
+        self.assertRaises(IndexError, delitem, lst, 3)
+
+        self.assertRaises(TypeError, delitem, 42, 1)
+        self.assertRaises(TypeError, delitem, {}, 1)
+        self.assertRaises(SystemError, delitem, NULL, 1)
+
+    def test_sequence_setslice(self):
+        setslice = _testcapi.sequence_setslice
+
+        # Correct case:
+        data = [1, 2, 3, 4, 5]
+        data_copy = data.copy()
+
+        setslice(data, 1, 3, [8, 9])
+        data_copy[1:3] = [8, 9]
+        self.assertEqual(data, data_copy)
+        self.assertEqual(data, [1, 8, 9, 4, 5])
+
+        # Custom class:
+        class Custom:
+            def __setitem__(self, index, value):
+                self.index = index
+                self.value = value
+
+        c = Custom()
+        setslice(c, 0, 5, 'abc')
+        self.assertEqual(c.index, slice(0, 5))
+        self.assertEqual(c.value, 'abc')
+
+        # Immutable sequences must raise:
+        bad_seq1 = (1, 2, 3, 4)
+        self.assertRaises(TypeError, setslice, bad_seq1, 1, 3, (8, 9))
+        self.assertEqual(bad_seq1, (1, 2, 3, 4))
+
+        bad_seq2 = 'abcd'
+        self.assertRaises(TypeError, setslice, bad_seq2, 1, 3, 'xy')
+        self.assertEqual(bad_seq2, 'abcd')
+
+        # Not a sequence:
+        self.assertRaises(TypeError, setslice, object(), 1, 3, 'xy')
+        self.assertRaises(SystemError, setslice, NULL, 1, 3, 'xy')
+
+        data_copy = data.copy()
+        setslice(data_copy, 1, 3, NULL)
+        self.assertEqual(data_copy, [1, 4, 5])
+
+    def test_sequence_delslice(self):
+        delslice = _testcapi.sequence_delslice
+
+        # Correct case:
+        data = [1, 2, 3, 4, 5]
+        data_copy = data.copy()
+
+        delslice(data, 1, 3)
+        del data_copy[1:3]
+        self.assertEqual(data, data_copy)
+        self.assertEqual(data, [1, 4, 5])
+
+        # Custom class:
+        class Custom:
+            def __delitem__(self, index):
+                self.index = index
+
+        c = Custom()
+        delslice(c, 0, 5)
+        self.assertEqual(c.index, slice(0, 5))
+
+        # Immutable sequences must raise:
+        bad_seq1 = (1, 2, 3, 4)
+        self.assertRaises(TypeError, delslice, bad_seq1, 1, 3)
+        self.assertEqual(bad_seq1, (1, 2, 3, 4))
+
+        bad_seq2 = 'abcd'
+        self.assertRaises(TypeError, delslice, bad_seq2, 1, 3)
+        self.assertEqual(bad_seq2, 'abcd')
+
+        # Not a sequence:
+        self.assertRaises(TypeError, delslice, object(), 1, 3)
+        self.assertRaises(SystemError, delslice, NULL, 1, 3)
+
+        mapping = {1: 'a', 2: 'b', 3: 'c'}
+        self.assertRaises(KeyError, delslice, mapping, 1, 3)
+        self.assertEqual(mapping, {1: 'a', 2: 'b', 3: 'c'})
+
+    def test_sequence_count(self):
+        count = _testcapi.sequence_count
+
+        lst = ['a', 'b', 'a']
+        self.assertEqual(count(lst, 'a'), 2)
+        self.assertEqual(count(lst, 'c'), 0)
+        self.assertEqual(count(iter(lst), 'a'), 2)
+        self.assertEqual(count(iter(lst), 'c'), 0)
+        self.assertEqual(count({'a': 2}, 'a'), 1)
+
+        self.assertRaises(TypeError, count, 42, 'a')
+        self.assertRaises(SystemError, count, [], NULL)
+        self.assertRaises(SystemError, count, [1], NULL)
+        self.assertRaises(SystemError, count, NULL, 'a')
+
+    def test_sequence_contains(self):
+        contains = _testcapi.sequence_contains
+
+        lst = ['a', 'b', 'a']
+        self.assertEqual(contains(lst, 'a'), 1)
+        self.assertEqual(contains(lst, 'c'), 0)
+        self.assertEqual(contains(iter(lst), 'a'), 1)
+        self.assertEqual(contains(iter(lst), 'c'), 0)
+        self.assertEqual(contains({'a': 2}, 'a'), 1)
+
+        # XXX Only for empty sequences. Should be SystemError?
+        self.assertEqual(contains([], NULL), 0)
+
+        self.assertRaises(TypeError, contains, 42, 'a')
+        self.assertRaises(SystemError, contains, [1], NULL)
+        # CRASHES contains({}, NULL)
+        # CRASHES contains(set(), NULL)
+        # CRASHES contains(NULL, 'a')
+
+    def test_sequence_index(self):
+        index = _testcapi.sequence_index
+
+        lst = ['a', 'b', 'a']
+        self.assertEqual(index(lst, 'a'), 0)
+        self.assertEqual(index(lst, 'b'), 1)
+        self.assertRaises(ValueError, index, lst, 'c')
+        self.assertEqual(index(iter(lst), 'a'), 0)
+        self.assertEqual(index(iter(lst), 'b'), 1)
+        self.assertRaises(ValueError, index, iter(lst), 'c')
+        dct = {'a': 2, 'b': 3}
+        self.assertEqual(index(dct, 'a'), 0)
+        self.assertEqual(index(dct, 'b'), 1)
+        self.assertRaises(ValueError, index, dct, 'c')
+
+        self.assertRaises(TypeError, index, 42, 'a')
+        self.assertRaises(SystemError, index, [], NULL)
+        self.assertRaises(SystemError, index, [1], NULL)
+        self.assertRaises(SystemError, index, NULL, 'a')
+
+    def test_sequence_list(self):
+        xlist = _testcapi.sequence_list
+        self.assertEqual(xlist(['a', 'b', 'c']), ['a', 'b', 'c'])
+        self.assertEqual(xlist(('a', 'b', 'c')), ['a', 'b', 'c'])
+        self.assertEqual(xlist(iter(['a', 'b', 'c'])), ['a', 'b', 'c'])
+        self.assertEqual(xlist(gen()), ['a', 'b', 'c'])
+
+        self.assertRaises(TypeError, xlist, 42)
+        self.assertRaises(SystemError, xlist, NULL)
+
+    def test_sequence_tuple(self):
+        xtuple = _testcapi.sequence_tuple
+        self.assertEqual(xtuple(['a', 'b', 'c']), ('a', 'b', 'c'))
+        self.assertEqual(xtuple(('a', 'b', 'c')), ('a', 'b', 'c'))
+        self.assertEqual(xtuple(iter(['a', 'b', 'c'])), ('a', 'b', 'c'))
+        self.assertEqual(xtuple(gen()), ('a', 'b', 'c'))
+
+        self.assertRaises(TypeError, xtuple, 42)
+        self.assertRaises(SystemError, xtuple, NULL)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_capi/test_dict.py b/Lib/test/test_capi/test_dict.py
new file mode 100644
index 0000000..0717708
--- /dev/null
+++ b/Lib/test/test_capi/test_dict.py
@@ -0,0 +1,378 @@
+import unittest
+import sys
+from collections import OrderedDict, UserDict
+from types import MappingProxyType
+from test import support
+from test.support import import_helper
+import _testcapi
+
+
+NULL = None
+
+class DictSubclass(dict):
+    def __getitem__(self, key):
+        raise RuntimeError('do not get evil')
+    def __setitem__(self, key, value):
+        raise RuntimeError('do not set evil')
+    def __delitem__(self, key):
+        raise RuntimeError('do not del evil')
+
+def gen():
+    yield 'a'
+    yield 'b'
+    yield 'c'
+
+
+class CAPITest(unittest.TestCase):
+
+    def test_dict_check(self):
+        check = _testcapi.dict_check
+        self.assertTrue(check({1: 2}))
+        self.assertTrue(check(OrderedDict({1: 2})))
+        self.assertFalse(check(UserDict({1: 2})))
+        self.assertFalse(check([1, 2]))
+        self.assertFalse(check(object()))
+        #self.assertFalse(check(NULL))
+
+    def test_dict_checkexact(self):
+        check = _testcapi.dict_checkexact
+        self.assertTrue(check({1: 2}))
+        self.assertFalse(check(OrderedDict({1: 2})))
+        self.assertFalse(check(UserDict({1: 2})))
+        self.assertFalse(check([1, 2]))
+        self.assertFalse(check(object()))
+        #self.assertFalse(check(NULL))
+
+    def test_dict_new(self):
+        dict_new = _testcapi.dict_new
+        dct = dict_new()
+        self.assertEqual(dct, {})
+        self.assertIs(type(dct), dict)
+        dct2 = dict_new()
+        self.assertIsNot(dct2, dct)
+
+    def test_dictproxy_new(self):
+        dictproxy_new = _testcapi.dictproxy_new
+        for dct in {1: 2}, OrderedDict({1: 2}), UserDict({1: 2}):
+            proxy = dictproxy_new(dct)
+            self.assertIs(type(proxy), MappingProxyType)
+            self.assertEqual(proxy, dct)
+            with self.assertRaises(TypeError):
+                proxy[1] = 3
+            self.assertEqual(proxy[1], 2)
+            dct[1] = 4
+            self.assertEqual(proxy[1], 4)
+
+        self.assertRaises(TypeError, dictproxy_new, [])
+        self.assertRaises(TypeError, dictproxy_new, 42)
+        # CRASHES dictproxy_new(NULL)
+
+    def test_dict_copy(self):
+        copy = _testcapi.dict_copy
+        for dct in {1: 2}, OrderedDict({1: 2}):
+            dct_copy = copy(dct)
+            self.assertIs(type(dct_copy), dict)
+            self.assertEqual(dct_copy, dct)
+
+        self.assertRaises(SystemError, copy, UserDict())
+        self.assertRaises(SystemError, copy, [])
+        self.assertRaises(SystemError, copy, 42)
+        self.assertRaises(SystemError, copy, NULL)
+
+    def test_dict_clear(self):
+        clear = _testcapi.dict_clear
+        dct = {1: 2}
+        clear(dct)
+        self.assertEqual(dct, {})
+
+        # NOTE: It is not safe to call it with OrderedDict.
+
+        # Has no effect for non-dicts.
+        dct = UserDict({1: 2})
+        clear(dct)
+        self.assertEqual(dct, {1: 2})
+        lst = [1, 2]
+        clear(lst)
+        self.assertEqual(lst, [1, 2])
+        clear(object())
+
+        # CRASHES? clear(NULL)
+
+    def test_dict_size(self):
+        size = _testcapi.dict_size
+        self.assertEqual(size({1: 2}), 1)
+        self.assertEqual(size(OrderedDict({1: 2})), 1)
+
+        self.assertRaises(SystemError, size, UserDict())
+        self.assertRaises(SystemError, size, [])
+        self.assertRaises(SystemError, size, 42)
+        self.assertRaises(SystemError, size, object())
+        self.assertRaises(SystemError, size, NULL)
+
+    def test_dict_getitem(self):
+        getitem = _testcapi.dict_getitem
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertEqual(getitem(dct, 'a'), 1)
+        self.assertIs(getitem(dct, 'b'), KeyError)
+        self.assertEqual(getitem(dct, '\U0001f40d'), 2)
+
+        dct2 = DictSubclass(dct)
+        self.assertEqual(getitem(dct2, 'a'), 1)
+        self.assertIs(getitem(dct2, 'b'), KeyError)
+
+        self.assertIs(getitem({}, []), KeyError)  # unhashable
+        self.assertIs(getitem(42, 'a'), KeyError)
+        self.assertIs(getitem([1], 0), KeyError)
+        # CRASHES getitem({}, NULL)
+        # CRASHES getitem(NULL, 'a')
+
+    def test_dict_getitemstring(self):
+        getitemstring = _testcapi.dict_getitemstring
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertEqual(getitemstring(dct, b'a'), 1)
+        self.assertIs(getitemstring(dct, b'b'), KeyError)
+        self.assertEqual(getitemstring(dct, '\U0001f40d'.encode()), 2)
+
+        dct2 = DictSubclass(dct)
+        self.assertEqual(getitemstring(dct2, b'a'), 1)
+        self.assertIs(getitemstring(dct2, b'b'), KeyError)
+
+        self.assertIs(getitemstring({}, b'\xff'), KeyError)
+        self.assertIs(getitemstring(42, b'a'), KeyError)
+        self.assertIs(getitemstring([], b'a'), KeyError)
+        # CRASHES getitemstring({}, NULL)
+        # CRASHES getitemstring(NULL, b'a')
+
+    def test_dict_getitemwitherror(self):
+        getitem = _testcapi.dict_getitemwitherror
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertEqual(getitem(dct, 'a'), 1)
+        self.assertIs(getitem(dct, 'b'), KeyError)
+        self.assertEqual(getitem(dct, '\U0001f40d'), 2)
+
+        dct2 = DictSubclass(dct)
+        self.assertEqual(getitem(dct2, 'a'), 1)
+        self.assertIs(getitem(dct2, 'b'), KeyError)
+
+        self.assertRaises(SystemError, getitem, 42, 'a')
+        self.assertRaises(TypeError, getitem, {}, [])  # unhashable
+        self.assertRaises(SystemError, getitem, [], 1)
+        self.assertRaises(SystemError, getitem, [], 'a')
+        # CRASHES getitem({}, NULL)
+        # CRASHES getitem(NULL, 'a')
+
+    def test_dict_contains(self):
+        contains = _testcapi.dict_contains
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertTrue(contains(dct, 'a'))
+        self.assertFalse(contains(dct, 'b'))
+        self.assertTrue(contains(dct, '\U0001f40d'))
+
+        dct2 = DictSubclass(dct)
+        self.assertTrue(contains(dct2, 'a'))
+        self.assertFalse(contains(dct2, 'b'))
+
+        self.assertRaises(TypeError, contains, {}, [])  # unhashable
+        # CRASHES contains({}, NULL)
+        # CRASHES contains(UserDict(), 'a')
+        # CRASHES contains(42, 'a')
+        # CRASHES contains(NULL, 'a')
+
+    def test_dict_setitem(self):
+        setitem = _testcapi.dict_setitem
+        dct = {}
+        setitem(dct, 'a', 5)
+        self.assertEqual(dct, {'a': 5})
+        setitem(dct, '\U0001f40d', 8)
+        self.assertEqual(dct, {'a': 5, '\U0001f40d': 8})
+
+        dct2 = DictSubclass()
+        setitem(dct2, 'a', 5)
+        self.assertEqual(dct2, {'a': 5})
+
+        self.assertRaises(TypeError, setitem, {}, [], 5)  # unhashable
+        self.assertRaises(SystemError, setitem, UserDict(), 'a', 5)
+        self.assertRaises(SystemError, setitem, [1], 0, 5)
+        self.assertRaises(SystemError, setitem, 42, 'a', 5)
+        # CRASHES setitem({}, NULL, 5)
+        # CRASHES setitem({}, 'a', NULL)
+        # CRASHES setitem(NULL, 'a', 5)
+
+    def test_dict_setitemstring(self):
+        setitemstring = _testcapi.dict_setitemstring
+        dct = {}
+        setitemstring(dct, b'a', 5)
+        self.assertEqual(dct, {'a': 5})
+        setitemstring(dct, '\U0001f40d'.encode(), 8)
+        self.assertEqual(dct, {'a': 5, '\U0001f40d': 8})
+
+        dct2 = DictSubclass()
+        setitemstring(dct2, b'a', 5)
+        self.assertEqual(dct2, {'a': 5})
+
+        self.assertRaises(UnicodeDecodeError, setitemstring, {}, b'\xff', 5)
+        self.assertRaises(SystemError, setitemstring, UserDict(), b'a', 5)
+        self.assertRaises(SystemError, setitemstring, 42, b'a', 5)
+        # CRASHES setitemstring({}, NULL, 5)
+        # CRASHES setitemstring({}, b'a', NULL)
+        # CRASHES setitemstring(NULL, b'a', 5)
+
+    def test_dict_delitem(self):
+        delitem = _testcapi.dict_delitem
+        dct = {'a': 1, 'c': 2, '\U0001f40d': 3}
+        delitem(dct, 'a')
+        self.assertEqual(dct, {'c': 2, '\U0001f40d': 3})
+        self.assertRaises(KeyError, delitem, dct, 'b')
+        delitem(dct, '\U0001f40d')
+        self.assertEqual(dct, {'c': 2})
+
+        dct2 = DictSubclass({'a': 1, 'c': 2})
+        delitem(dct2, 'a')
+        self.assertEqual(dct2, {'c': 2})
+        self.assertRaises(KeyError, delitem, dct2, 'b')
+
+        self.assertRaises(TypeError, delitem, {}, [])  # unhashable
+        self.assertRaises(SystemError, delitem, UserDict({'a': 1}), 'a')
+        self.assertRaises(SystemError, delitem, [1], 0)
+        self.assertRaises(SystemError, delitem, 42, 'a')
+        # CRASHES delitem({}, NULL)
+        # CRASHES delitem(NULL, 'a')
+
+    def test_dict_delitemstring(self):
+        delitemstring = _testcapi.dict_delitemstring
+        dct = {'a': 1, 'c': 2, '\U0001f40d': 3}
+        delitemstring(dct, b'a')
+        self.assertEqual(dct, {'c': 2, '\U0001f40d': 3})
+        self.assertRaises(KeyError, delitemstring, dct, b'b')
+        delitemstring(dct, '\U0001f40d'.encode())
+        self.assertEqual(dct, {'c': 2})
+
+        dct2 = DictSubclass({'a': 1, 'c': 2})
+        delitemstring(dct2, b'a')
+        self.assertEqual(dct2, {'c': 2})
+        self.assertRaises(KeyError, delitemstring, dct2, b'b')
+
+        self.assertRaises(UnicodeDecodeError, delitemstring, {}, b'\xff')
+        self.assertRaises(SystemError, delitemstring, UserDict({'a': 1}), b'a')
+        self.assertRaises(SystemError, delitemstring, 42, b'a')
+        # CRASHES delitemstring({}, NULL)
+        # CRASHES delitemstring(NULL, b'a')
+
+    def test_dict_setdefault(self):
+        setdefault = _testcapi.dict_setdefault
+        dct = {}
+        self.assertEqual(setdefault(dct, 'a', 5), 5)
+        self.assertEqual(dct, {'a': 5})
+        self.assertEqual(setdefault(dct, 'a', 8), 5)
+        self.assertEqual(dct, {'a': 5})
+
+        dct2 = DictSubclass()
+        self.assertEqual(setdefault(dct2, 'a', 5), 5)
+        self.assertEqual(dct2, {'a': 5})
+        self.assertEqual(setdefault(dct2, 'a', 8), 5)
+        self.assertEqual(dct2, {'a': 5})
+
+        self.assertRaises(TypeError, setdefault, {}, [], 5)  # unhashable
+        self.assertRaises(SystemError, setdefault, UserDict(), 'a', 5)
+        self.assertRaises(SystemError, setdefault, [1], 0, 5)
+        self.assertRaises(SystemError, setdefault, 42, 'a', 5)
+        # CRASHES setdefault({}, NULL, 5)
+        # CRASHES setdefault({}, 'a', NULL)
+        # CRASHES setdefault(NULL, 'a', 5)
+
+    def test_mapping_keys_valuesitems(self):
+        class BadMapping(dict):
+            def keys(self):
+                return None
+            def values(self):
+                return None
+            def items(self):
+                return None
+        dict_obj = {'foo': 1, 'bar': 2, 'spam': 3}
+        for mapping in [dict_obj, DictSubclass(dict_obj), BadMapping(dict_obj)]:
+            self.assertListEqual(_testcapi.dict_keys(mapping),
+                                 list(dict_obj.keys()))
+            self.assertListEqual(_testcapi.dict_values(mapping),
+                                 list(dict_obj.values()))
+            self.assertListEqual(_testcapi.dict_items(mapping),
+                                 list(dict_obj.items()))
+
+    def test_dict_keys_valuesitems_bad_arg(self):
+        for mapping in UserDict(), [], object():
+            self.assertRaises(SystemError, _testcapi.dict_keys, mapping)
+            self.assertRaises(SystemError, _testcapi.dict_values, mapping)
+            self.assertRaises(SystemError, _testcapi.dict_items, mapping)
+
+    def test_dict_next(self):
+        dict_next = _testcapi.dict_next
+        self.assertIsNone(dict_next({}, 0))
+        dct = {'a': 1, 'b': 2, 'c': 3}
+        pos = 0
+        pairs = []
+        while True:
+            res = dict_next(dct, pos)
+            if res is None:
+                break
+            rc, pos, key, value = res
+            self.assertEqual(rc, 1)
+            pairs.append((key, value))
+        self.assertEqual(pairs, list(dct.items()))
+
+        # CRASHES dict_next(NULL, 0)
+
+    def test_dict_update(self):
+        update = _testcapi.dict_update
+        for cls1 in dict, DictSubclass:
+            for cls2 in dict, DictSubclass, UserDict:
+                dct = cls1({'a': 1, 'b': 2})
+                update(dct, cls2({'b': 3, 'c': 4}))
+                self.assertEqual(dct, {'a': 1, 'b': 3, 'c': 4})
+
+        self.assertRaises(AttributeError, update, {}, [])
+        self.assertRaises(AttributeError, update, {}, 42)
+        self.assertRaises(SystemError, update, UserDict(), {})
+        self.assertRaises(SystemError, update, 42, {})
+        self.assertRaises(SystemError, update, {}, NULL)
+        self.assertRaises(SystemError, update, NULL, {})
+
+    def test_dict_merge(self):
+        merge = _testcapi.dict_merge
+        for cls1 in dict, DictSubclass:
+            for cls2 in dict, DictSubclass, UserDict:
+                dct = cls1({'a': 1, 'b': 2})
+                merge(dct, cls2({'b': 3, 'c': 4}), 0)
+                self.assertEqual(dct, {'a': 1, 'b': 2, 'c': 4})
+                dct = cls1({'a': 1, 'b': 2})
+                merge(dct, cls2({'b': 3, 'c': 4}), 1)
+                self.assertEqual(dct, {'a': 1, 'b': 3, 'c': 4})
+
+        self.assertRaises(AttributeError, merge, {}, [], 0)
+        self.assertRaises(AttributeError, merge, {}, 42, 0)
+        self.assertRaises(SystemError, merge, UserDict(), {}, 0)
+        self.assertRaises(SystemError, merge, 42, {}, 0)
+        self.assertRaises(SystemError, merge, {}, NULL, 0)
+        self.assertRaises(SystemError, merge, NULL, {}, 0)
+
+    def test_dict_mergefromseq2(self):
+        mergefromseq2 = _testcapi.dict_mergefromseq2
+        for cls1 in dict, DictSubclass:
+            for cls2 in list, iter:
+                dct = cls1({'a': 1, 'b': 2})
+                mergefromseq2(dct, cls2([('b', 3), ('c', 4)]), 0)
+                self.assertEqual(dct, {'a': 1, 'b': 2, 'c': 4})
+                dct = cls1({'a': 1, 'b': 2})
+                mergefromseq2(dct, cls2([('b', 3), ('c', 4)]), 1)
+                self.assertEqual(dct, {'a': 1, 'b': 3, 'c': 4})
+
+        self.assertRaises(ValueError, mergefromseq2, {}, [(1,)], 0)
+        self.assertRaises(ValueError, mergefromseq2, {}, [(1, 2, 3)], 0)
+        self.assertRaises(TypeError, mergefromseq2, {}, [1], 0)
+        self.assertRaises(TypeError, mergefromseq2, {}, 42, 0)
+        # CRASHES mergefromseq2(UserDict(), [], 0)
+        # CRASHES mergefromseq2(42, [], 0)
+        # CRASHES mergefromseq2({}, NULL, 0)
+        # CRASHES mergefromseq2(NULL, {}, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py
index 3d49497..2a71ac5 100644
--- a/Lib/test/test_capi/test_misc.py
+++ b/Lib/test/test_capi/test_misc.py
@@ -301,137 +301,6 @@ class CAPITest(unittest.TestCase):
     def test_buildvalue_N(self):
         _testcapi.test_buildvalue_N()
 
-    def test_mapping_keys_values_items(self):
-        class Mapping1(dict):
-            def keys(self):
-                return list(super().keys())
-            def values(self):
-                return list(super().values())
-            def items(self):
-                return list(super().items())
-        class Mapping2(dict):
-            def keys(self):
-                return tuple(super().keys())
-            def values(self):
-                return tuple(super().values())
-            def items(self):
-                return tuple(super().items())
-        dict_obj = {'foo': 1, 'bar': 2, 'spam': 3}
-
-        for mapping in [{}, OrderedDict(), Mapping1(), Mapping2(),
-                        dict_obj, OrderedDict(dict_obj),
-                        Mapping1(dict_obj), Mapping2(dict_obj)]:
-            self.assertListEqual(_testcapi.get_mapping_keys(mapping),
-                                 list(mapping.keys()))
-            self.assertListEqual(_testcapi.get_mapping_values(mapping),
-                                 list(mapping.values()))
-            self.assertListEqual(_testcapi.get_mapping_items(mapping),
-                                 list(mapping.items()))
-
-    def test_mapping_keys_values_items_bad_arg(self):
-        self.assertRaises(AttributeError, _testcapi.get_mapping_keys, None)
-        self.assertRaises(AttributeError, _testcapi.get_mapping_values, None)
-        self.assertRaises(AttributeError, _testcapi.get_mapping_items, None)
-
-        class BadMapping:
-            def keys(self):
-                return None
-            def values(self):
-                return None
-            def items(self):
-                return None
-        bad_mapping = BadMapping()
-        self.assertRaises(TypeError, _testcapi.get_mapping_keys, bad_mapping)
-        self.assertRaises(TypeError, _testcapi.get_mapping_values, bad_mapping)
-        self.assertRaises(TypeError, _testcapi.get_mapping_items, bad_mapping)
-
-    def test_mapping_has_key(self):
-        dct = {'a': 1}
-        self.assertTrue(_testcapi.mapping_has_key(dct, 'a'))
-        self.assertFalse(_testcapi.mapping_has_key(dct, 'b'))
-
-        class SubDict(dict):
-            pass
-
-        dct2 = SubDict({'a': 1})
-        self.assertTrue(_testcapi.mapping_has_key(dct2, 'a'))
-        self.assertFalse(_testcapi.mapping_has_key(dct2, 'b'))
-
-    def test_sequence_set_slice(self):
-        # Correct case:
-        data = [1, 2, 3, 4, 5]
-        data_copy = data.copy()
-
-        _testcapi.sequence_set_slice(data, 1, 3, [8, 9])
-        data_copy[1:3] = [8, 9]
-        self.assertEqual(data, data_copy)
-        self.assertEqual(data, [1, 8, 9, 4, 5])
-
-        # Custom class:
-        class Custom:
-            def __setitem__(self, index, value):
-                self.index = index
-                self.value = value
-
-        c = Custom()
-        _testcapi.sequence_set_slice(c, 0, 5, 'abc')
-        self.assertEqual(c.index, slice(0, 5))
-        self.assertEqual(c.value, 'abc')
-
-        # Immutable sequences must raise:
-        bad_seq1 = (1, 2, 3, 4)
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_set_slice(bad_seq1, 1, 3, (8, 9))
-        self.assertEqual(bad_seq1, (1, 2, 3, 4))
-
-        bad_seq2 = 'abcd'
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_set_slice(bad_seq2, 1, 3, 'xy')
-        self.assertEqual(bad_seq2, 'abcd')
-
-        # Not a sequence:
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_set_slice(None, 1, 3, 'xy')
-
-    def test_sequence_del_slice(self):
-        # Correct case:
-        data = [1, 2, 3, 4, 5]
-        data_copy = data.copy()
-
-        _testcapi.sequence_del_slice(data, 1, 3)
-        del data_copy[1:3]
-        self.assertEqual(data, data_copy)
-        self.assertEqual(data, [1, 4, 5])
-
-        # Custom class:
-        class Custom:
-            def __delitem__(self, index):
-                self.index = index
-
-        c = Custom()
-        _testcapi.sequence_del_slice(c, 0, 5)
-        self.assertEqual(c.index, slice(0, 5))
-
-        # Immutable sequences must raise:
-        bad_seq1 = (1, 2, 3, 4)
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_del_slice(bad_seq1, 1, 3)
-        self.assertEqual(bad_seq1, (1, 2, 3, 4))
-
-        bad_seq2 = 'abcd'
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_del_slice(bad_seq2, 1, 3)
-        self.assertEqual(bad_seq2, 'abcd')
-
-        # Not a sequence:
-        with self.assertRaises(TypeError):
-            _testcapi.sequence_del_slice(None, 1, 3)
-
-        mapping = {1: 'a', 2: 'b', 3: 'c'}
-        with self.assertRaises(KeyError):
-            _testcapi.sequence_del_slice(mapping, 1, 3)
-        self.assertEqual(mapping, {1: 'a', 2: 'b', 3: 'c'})
-
     @unittest.skipUnless(hasattr(_testcapi, 'negative_refcount'),
                          'need _testcapi.negative_refcount')
     def test_negative_refcount(self):
diff --git a/Lib/test/test_class.py b/Lib/test/test_class.py
index d7a48e5..7a15976 100644
--- a/Lib/test/test_class.py
+++ b/Lib/test/test_class.py
@@ -455,8 +455,8 @@ class ClassTests(unittest.TestCase):
                 self.attr = 1
 
         a = A()
-        self.assertEqual(_testcapi.hasattr_string(a, "attr"), True)
-        self.assertEqual(_testcapi.hasattr_string(a, "noattr"), False)
+        self.assertEqual(_testcapi.object_hasattrstring(a, b"attr"), 1)
+        self.assertEqual(_testcapi.object_hasattrstring(a, b"noattr"), 0)
         self.assertIsNone(sys.exception())
 
     def testDel(self):
diff --git a/Misc/NEWS.d/next/Tests/2023-07-24-16-56-59.gh-issue-107178.Gq1usE.rst b/Misc/NEWS.d/next/Tests/2023-07-24-16-56-59.gh-issue-107178.Gq1usE.rst
new file mode 100644
index 0000000..dd6becf
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2023-07-24-16-56-59.gh-issue-107178.Gq1usE.rst
@@ -0,0 +1,2 @@
+Add the C API test for functions in the Mapping Protocol, the Sequence
+Protocol and some functions in the Object Protocol.
diff --git a/Modules/Setup.stdlib.in b/Modules/Setup.stdlib.in
index 0fc7955..3e01e25 100644
--- a/Modules/Setup.stdlib.in
+++ b/Modules/Setup.stdlib.in
@@ -168,7 +168,7 @@
 @MODULE__XXTESTFUZZ_TRUE@_xxtestfuzz _xxtestfuzz/_xxtestfuzz.c _xxtestfuzz/fuzzer.c
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
 @MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c
-@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/unicode.c _testcapi/getargs.c _testcapi/pytime.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyos.c _testcapi/immortal.c _testcapi/heaptype_relative.c _testcapi/gc.c
+@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/getargs.c _testcapi/pytime.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyos.c _testcapi/immortal.c _testcapi/heaptype_relative.c _testcapi/gc.c
 @MODULE__TESTCLINIC_TRUE@_testclinic _testclinic.c
 
 # Some testing modules MUST be built as shared libraries.
diff --git a/Modules/_testcapi/abstract.c b/Modules/_testcapi/abstract.c
new file mode 100644
index 0000000..9715efb
--- /dev/null
+++ b/Modules/_testcapi/abstract.c
@@ -0,0 +1,535 @@
+#include <stddef.h>               // ptrdiff_t
+
+#define PY_SSIZE_T_CLEAN
+#include "parts.h"
+
+#define NULLABLE(x) do { if (x == Py_None) x = NULL; } while (0);
+
+#define RETURN_INT(value) do {          \
+        int _ret = (value);             \
+        if (_ret == -1) {               \
+            return NULL;                \
+        }                               \
+        return PyLong_FromLong(_ret);   \
+    } while (0)
+
+#define RETURN_SIZE(value) do {             \
+        Py_ssize_t _ret = (value);          \
+        if (_ret == -1) {                   \
+            return NULL;                    \
+        }                                   \
+        return PyLong_FromSsize_t(_ret);    \
+    } while (0)
+
+
+static PyObject *
+object_getattr(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *attr_name;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &attr_name)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(attr_name);
+    return PyObject_GetAttr(obj, attr_name);
+}
+
+static PyObject *
+object_getattrstring(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    const char *attr_name;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &obj, &attr_name, &size)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    return PyObject_GetAttrString(obj, attr_name);
+}
+
+static PyObject *
+object_hasattr(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *attr_name;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &attr_name)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(attr_name);
+    return PyLong_FromLong(PyObject_HasAttr(obj, attr_name));
+}
+
+static PyObject *
+object_hasattrstring(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    const char *attr_name;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &obj, &attr_name, &size)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    return PyLong_FromLong(PyObject_HasAttrString(obj, attr_name));
+}
+
+static PyObject *
+object_setattr(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *attr_name, *value;
+    if (!PyArg_ParseTuple(args, "OOO", &obj, &attr_name, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(attr_name);
+    NULLABLE(value);
+    RETURN_INT(PyObject_SetAttr(obj, attr_name, value));
+}
+
+static PyObject *
+object_setattrstring(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *value;
+    const char *attr_name;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#O", &obj, &attr_name, &size, &value)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(value);
+    RETURN_INT(PyObject_SetAttrString(obj, attr_name, value));
+}
+
+static PyObject *
+object_delattr(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *attr_name;
+if (!PyArg_ParseTuple(args, "OO", &obj, &attr_name)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(attr_name);
+    RETURN_INT(PyObject_DelAttr(obj, attr_name));
+}
+
+static PyObject *
+object_delattrstring(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    const char *attr_name;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &obj, &attr_name, &size)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    RETURN_INT(PyObject_DelAttrString(obj, attr_name));
+}
+
+
+static PyObject *
+mapping_check(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyMapping_Check(obj));
+}
+
+static PyObject *
+mapping_size(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PyMapping_Size(obj));
+}
+
+static PyObject *
+mapping_length(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PyMapping_Length(obj));
+}
+
+static PyObject *
+object_getitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    return PyObject_GetItem(mapping, key);
+}
+
+static PyObject *
+mapping_getitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    return PyMapping_GetItemString(mapping, key);
+}
+
+static PyObject *
+mapping_haskey(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    return PyLong_FromLong(PyMapping_HasKey(mapping, key));
+}
+
+static PyObject *
+mapping_haskeystring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    return PyLong_FromLong(PyMapping_HasKeyString(mapping, key));
+}
+
+static PyObject *
+object_setitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key, *value;
+    if (!PyArg_ParseTuple(args, "OOO", &mapping, &key, &value)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    NULLABLE(value);
+    RETURN_INT(PyObject_SetItem(mapping, key, value));
+}
+
+static PyObject *
+mapping_setitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *value;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#O", &mapping, &key, &size, &value)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(value);
+    RETURN_INT(PyMapping_SetItemString(mapping, key, value));
+}
+
+static PyObject *
+object_delitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    RETURN_INT(PyObject_DelItem(mapping, key));
+}
+
+static PyObject *
+mapping_delitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    RETURN_INT(PyMapping_DelItem(mapping, key));
+}
+
+static PyObject *
+mapping_delitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    RETURN_INT(PyMapping_DelItemString(mapping, key));
+}
+
+static PyObject *
+mapping_keys(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyMapping_Keys(obj);
+}
+
+static PyObject *
+mapping_values(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyMapping_Values(obj);
+}
+
+static PyObject *
+mapping_items(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyMapping_Items(obj);
+}
+
+
+static PyObject *
+sequence_check(PyObject* self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PySequence_Check(obj));
+}
+
+static PyObject *
+sequence_size(PyObject* self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PySequence_Size(obj));
+}
+
+static PyObject *
+sequence_length(PyObject* self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PySequence_Length(obj));
+}
+
+static PyObject *
+sequence_concat(PyObject *self, PyObject *args)
+{
+    PyObject *seq1, *seq2;
+    if (!PyArg_ParseTuple(args, "OO", &seq1, &seq2)) {
+        return NULL;
+    }
+    NULLABLE(seq1);
+    NULLABLE(seq2);
+
+    return PySequence_Concat(seq1, seq2);
+}
+
+static PyObject *
+sequence_repeat(PyObject *self, PyObject *args)
+{
+    PyObject *seq;
+    Py_ssize_t count;
+    if (!PyArg_ParseTuple(args, "On", &seq, &count)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+
+    return PySequence_Repeat(seq, count);
+}
+
+static PyObject *
+sequence_inplaceconcat(PyObject *self, PyObject *args)
+{
+    PyObject *seq1, *seq2;
+    if (!PyArg_ParseTuple(args, "OO", &seq1, &seq2)) {
+        return NULL;
+    }
+    NULLABLE(seq1);
+    NULLABLE(seq2);
+
+    return PySequence_InPlaceConcat(seq1, seq2);
+}
+
+static PyObject *
+sequence_inplacerepeat(PyObject *self, PyObject *args)
+{
+    PyObject *seq;
+    Py_ssize_t count;
+    if (!PyArg_ParseTuple(args, "On", &seq, &count)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+
+    return PySequence_InPlaceRepeat(seq, count);
+}
+
+static PyObject *
+sequence_getitem(PyObject *self, PyObject *args)
+{
+    PyObject *seq;
+    Py_ssize_t i;
+    if (!PyArg_ParseTuple(args, "On", &seq, &i)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+
+    return PySequence_GetItem(seq, i);
+}
+
+static PyObject *
+sequence_setitem(PyObject *self, PyObject *args)
+{
+    Py_ssize_t i;
+    PyObject *seq, *val;
+    if (!PyArg_ParseTuple(args, "OnO", &seq, &i, &val)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+    NULLABLE(val);
+
+    RETURN_INT(PySequence_SetItem(seq, i, val));
+}
+
+
+static PyObject *
+sequence_delitem(PyObject *self, PyObject *args)
+{
+    Py_ssize_t i;
+    PyObject *seq;
+    if (!PyArg_ParseTuple(args, "On", &seq, &i)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+
+    RETURN_INT(PySequence_DelItem(seq, i));
+}
+
+static PyObject *
+sequence_setslice(PyObject* self, PyObject *args)
+{
+    PyObject *sequence, *obj;
+    Py_ssize_t i1, i2;
+    if (!PyArg_ParseTuple(args, "OnnO", &sequence, &i1, &i2, &obj)) {
+        return NULL;
+    }
+    NULLABLE(sequence);
+    NULLABLE(obj);
+
+    RETURN_INT(PySequence_SetSlice(sequence, i1, i2, obj));
+}
+
+static PyObject *
+sequence_delslice(PyObject *self, PyObject *args)
+{
+    PyObject *sequence;
+    Py_ssize_t i1, i2;
+    if (!PyArg_ParseTuple(args, "Onn", &sequence, &i1, &i2)) {
+        return NULL;
+    }
+    NULLABLE(sequence);
+
+    RETURN_INT(PySequence_DelSlice(sequence, i1, i2));
+}
+
+static PyObject *
+sequence_count(PyObject *self, PyObject *args)
+{
+    PyObject *seq, *value;
+    if (!PyArg_ParseTuple(args, "OO", &seq, &value)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+    NULLABLE(value);
+
+    RETURN_SIZE(PySequence_Count(seq, value));
+}
+
+static PyObject *
+sequence_contains(PyObject *self, PyObject *args)
+{
+    PyObject *seq, *value;
+    if (!PyArg_ParseTuple(args, "OO", &seq, &value)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+    NULLABLE(value);
+
+    RETURN_INT(PySequence_Contains(seq, value));
+}
+
+static PyObject *
+sequence_index(PyObject *self, PyObject *args)
+{
+    PyObject *seq, *value;
+    if (!PyArg_ParseTuple(args, "OO", &seq, &value)) {
+        return NULL;
+    }
+    NULLABLE(seq);
+    NULLABLE(value);
+
+    RETURN_SIZE(PySequence_Index(seq, value));
+}
+
+static PyObject *
+sequence_list(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PySequence_List(obj);
+}
+
+static PyObject *
+sequence_tuple(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PySequence_Tuple(obj);
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"object_getattr", object_getattr, METH_VARARGS},
+    {"object_getattrstring", object_getattrstring, METH_VARARGS},
+    {"object_hasattr", object_hasattr, METH_VARARGS},
+    {"object_hasattrstring", object_hasattrstring, METH_VARARGS},
+    {"object_setattr", object_setattr, METH_VARARGS},
+    {"object_setattrstring", object_setattrstring, METH_VARARGS},
+    {"object_delattr", object_delattr, METH_VARARGS},
+    {"object_delattrstring", object_delattrstring, METH_VARARGS},
+
+    {"mapping_check", mapping_check, METH_O},
+    {"mapping_size", mapping_size, METH_O},
+    {"mapping_length", mapping_length, METH_O},
+    {"object_getitem", object_getitem, METH_VARARGS},
+    {"mapping_getitemstring", mapping_getitemstring, METH_VARARGS},
+    {"mapping_haskey", mapping_haskey, METH_VARARGS},
+    {"mapping_haskeystring", mapping_haskeystring, METH_VARARGS},
+    {"object_setitem", object_setitem, METH_VARARGS},
+    {"mapping_setitemstring", mapping_setitemstring, METH_VARARGS},
+    {"object_delitem", object_delitem, METH_VARARGS},
+    {"mapping_delitem", mapping_delitem, METH_VARARGS},
+    {"mapping_delitemstring", mapping_delitemstring, METH_VARARGS},
+    {"mapping_keys", mapping_keys, METH_O},
+    {"mapping_values", mapping_values, METH_O},
+    {"mapping_items", mapping_items, METH_O},
+
+    {"sequence_check", sequence_check, METH_O},
+    {"sequence_size", sequence_size, METH_O},
+    {"sequence_length", sequence_length, METH_O},
+    {"sequence_concat", sequence_concat, METH_VARARGS},
+    {"sequence_repeat", sequence_repeat, METH_VARARGS},
+    {"sequence_inplaceconcat", sequence_inplaceconcat, METH_VARARGS},
+    {"sequence_inplacerepeat", sequence_inplacerepeat, METH_VARARGS},
+    {"sequence_getitem", sequence_getitem, METH_VARARGS},
+    {"sequence_setitem", sequence_setitem, METH_VARARGS},
+    {"sequence_delitem", sequence_delitem, METH_VARARGS},
+    {"sequence_setslice", sequence_setslice, METH_VARARGS},
+    {"sequence_delslice", sequence_delslice, METH_VARARGS},
+    {"sequence_count", sequence_count, METH_VARARGS},
+    {"sequence_contains", sequence_contains, METH_VARARGS},
+    {"sequence_index", sequence_index, METH_VARARGS},
+    {"sequence_list", sequence_list, METH_O},
+    {"sequence_tuple", sequence_tuple, METH_O},
+
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Abstract(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/Modules/_testcapi/dict.c b/Modules/_testcapi/dict.c
new file mode 100644
index 0000000..c0f26e7
--- /dev/null
+++ b/Modules/_testcapi/dict.c
@@ -0,0 +1,323 @@
+#include <stddef.h>               // ptrdiff_t
+
+#define PY_SSIZE_T_CLEAN
+#include "parts.h"
+
+#define NULLABLE(x) do { if (x == Py_None) x = NULL; } while (0);
+
+#define RETURN_INT(value) do {          \
+        int _ret = (value);             \
+        if (_ret == -1) {               \
+            return NULL;                \
+        }                               \
+        return PyLong_FromLong(_ret);   \
+    } while (0)
+
+#define RETURN_SIZE(value) do {             \
+        Py_ssize_t _ret = (value);          \
+        if (_ret == -1) {                   \
+            return NULL;                    \
+        }                                   \
+        return PyLong_FromSsize_t(_ret);    \
+    } while (0)
+
+
+static PyObject *
+dict_check(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyDict_Check(obj));
+}
+
+static PyObject *
+dict_checkexact(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyLong_FromLong(PyDict_CheckExact(obj));
+}
+
+static PyObject *
+dict_new(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    return PyDict_New();
+}
+
+static PyObject *
+dictproxy_new(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyDictProxy_New(obj);
+}
+
+static PyObject *
+dict_clear(PyObject *self, PyObject *obj)
+{
+    PyDict_Clear(obj);
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+dict_copy(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyDict_Copy(obj);
+}
+
+static PyObject *
+dict_contains(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *key;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &key)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(key);
+    RETURN_INT(PyDict_Contains(obj, key));
+}
+
+static PyObject *
+dict_size(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    RETURN_SIZE(PyDict_Size(obj));
+}
+
+static PyObject *
+dict_getitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    PyObject *value = PyDict_GetItem(mapping, key);
+    if (value == NULL) {
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
+        return Py_NewRef(PyExc_KeyError);
+    }
+    return Py_NewRef(value);
+}
+
+static PyObject *
+dict_getitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    PyObject *value = PyDict_GetItemString(mapping, key);
+    if (value == NULL) {
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
+        return Py_NewRef(PyExc_KeyError);
+    }
+    return Py_NewRef(value);
+}
+
+static PyObject *
+dict_getitemwitherror(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    PyObject *value = PyDict_GetItemWithError(mapping, key);
+    if (value == NULL) {
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
+        return Py_NewRef(PyExc_KeyError);
+    }
+    return Py_NewRef(value);
+}
+
+static PyObject *
+dict_setitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key, *value;
+    if (!PyArg_ParseTuple(args, "OOO", &mapping, &key, &value)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    NULLABLE(value);
+    RETURN_INT(PyDict_SetItem(mapping, key, value));
+}
+
+static PyObject *
+dict_setitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *value;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#O", &mapping, &key, &size, &value)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(value);
+    RETURN_INT(PyDict_SetItemString(mapping, key, value));
+}
+
+static PyObject *
+dict_setdefault(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key, *defaultobj;
+    if (!PyArg_ParseTuple(args, "OOO", &mapping, &key, &defaultobj)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    NULLABLE(defaultobj);
+    return PyDict_SetDefault(mapping, key, defaultobj);
+}
+
+static PyObject *
+dict_delitem(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    RETURN_INT(PyDict_DelItem(mapping, key));
+}
+
+static PyObject *
+dict_delitemstring(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    RETURN_INT(PyDict_DelItemString(mapping, key));
+}
+
+static PyObject *
+dict_keys(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyDict_Keys(obj);
+}
+
+static PyObject *
+dict_values(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyDict_Values(obj);
+}
+
+static PyObject *
+dict_items(PyObject *self, PyObject *obj)
+{
+    NULLABLE(obj);
+    return PyDict_Items(obj);
+}
+
+static PyObject *
+dict_next(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key, *value;
+    Py_ssize_t pos;
+    if (!PyArg_ParseTuple(args, "On", &mapping, &pos)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    int rc = PyDict_Next(mapping, &pos, &key, &value);
+    if (rc != 0) {
+        return Py_BuildValue("inOO", rc, pos, key, value);
+    }
+    if (PyErr_Occurred()) {
+        return NULL;
+    }
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+dict_merge(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *mapping2;
+    int override;
+    if (!PyArg_ParseTuple(args, "OOi", &mapping, &mapping2, &override)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(mapping2);
+    RETURN_INT(PyDict_Merge(mapping, mapping2, override));
+}
+
+static PyObject *
+dict_update(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *mapping2;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &mapping2)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(mapping2);
+    RETURN_INT(PyDict_Update(mapping, mapping2));
+}
+
+static PyObject *
+dict_mergefromseq2(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *seq;
+    int override;
+    if (!PyArg_ParseTuple(args, "OOi", &mapping, &seq, &override)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(seq);
+    RETURN_INT(PyDict_MergeFromSeq2(mapping, seq, override));
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"dict_check", dict_check, METH_O},
+    {"dict_checkexact", dict_checkexact, METH_O},
+    {"dict_new", dict_new, METH_NOARGS},
+    {"dictproxy_new", dictproxy_new, METH_O},
+    {"dict_clear", dict_clear, METH_O},
+    {"dict_copy", dict_copy, METH_O},
+    {"dict_size", dict_size, METH_O},
+    {"dict_getitem", dict_getitem, METH_VARARGS},
+    {"dict_getitemwitherror", dict_getitemwitherror, METH_VARARGS},
+    {"dict_getitemstring", dict_getitemstring, METH_VARARGS},
+    {"dict_contains", dict_contains, METH_VARARGS},
+    {"dict_setitem", dict_setitem, METH_VARARGS},
+    {"dict_setitemstring", dict_setitemstring, METH_VARARGS},
+    {"dict_delitem", dict_delitem, METH_VARARGS},
+    {"dict_delitemstring", dict_delitemstring, METH_VARARGS},
+    {"dict_setdefault", dict_setdefault, METH_VARARGS},
+    {"dict_keys", dict_keys, METH_O},
+    {"dict_values", dict_values, METH_O},
+    {"dict_items", dict_items, METH_O},
+    {"dict_next", dict_next, METH_VARARGS},
+    {"dict_merge", dict_merge, METH_VARARGS},
+    {"dict_update", dict_update, METH_VARARGS},
+    {"dict_mergefromseq2", dict_mergefromseq2, METH_VARARGS},
+
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Dict(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/Modules/_testcapi/parts.h b/Modules/_testcapi/parts.h
index d1991ac..f37be9b 100644
--- a/Modules/_testcapi/parts.h
+++ b/Modules/_testcapi/parts.h
@@ -26,6 +26,7 @@
 
 int _PyTestCapi_Init_Vectorcall(PyObject *module);
 int _PyTestCapi_Init_Heaptype(PyObject *module);
+int _PyTestCapi_Init_Abstract(PyObject *module);
 int _PyTestCapi_Init_Unicode(PyObject *module);
 int _PyTestCapi_Init_GetArgs(PyObject *module);
 int _PyTestCapi_Init_PyTime(PyObject *module);
@@ -35,6 +36,7 @@ int _PyTestCapi_Init_Mem(PyObject *module);
 int _PyTestCapi_Init_Watchers(PyObject *module);
 int _PyTestCapi_Init_Long(PyObject *module);
 int _PyTestCapi_Init_Float(PyObject *module);
+int _PyTestCapi_Init_Dict(PyObject *module);
 int _PyTestCapi_Init_Structmember(PyObject *module);
 int _PyTestCapi_Init_Exceptions(PyObject *module);
 int _PyTestCapi_Init_Code(PyObject *module);
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 098d2cf..ee6f02d 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1988,7 +1988,7 @@ return_result_with_error(PyObject *self, PyObject *args)
     Py_RETURN_NONE;
 }
 
-static PyObject*
+static PyObject *
 getitem_with_error(PyObject *self, PyObject *args)
 {
     PyObject *map, *key;
@@ -2066,90 +2066,6 @@ py_w_stopcode(PyObject *self, PyObject *args)
 
 
 static PyObject *
-get_mapping_keys(PyObject* self, PyObject *obj)
-{
-    return PyMapping_Keys(obj);
-}
-
-static PyObject *
-get_mapping_values(PyObject* self, PyObject *obj)
-{
-    return PyMapping_Values(obj);
-}
-
-static PyObject *
-get_mapping_items(PyObject* self, PyObject *obj)
-{
-    return PyMapping_Items(obj);
-}
-
-static PyObject *
-test_mapping_has_key_string(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    PyObject *context = PyDict_New();
-    PyObject *val = PyLong_FromLong(1);
-
-    // Since this uses `const char*` it is easier to test this in C:
-    PyDict_SetItemString(context, "a", val);
-    if (!PyMapping_HasKeyString(context, "a")) {
-        PyErr_SetString(PyExc_RuntimeError,
-                        "Existing mapping key does not exist");
-        return NULL;
-    }
-    if (PyMapping_HasKeyString(context, "b")) {
-        PyErr_SetString(PyExc_RuntimeError,
-                        "Missing mapping key exists");
-        return NULL;
-    }
-
-    Py_DECREF(val);
-    Py_DECREF(context);
-    Py_RETURN_NONE;
-}
-
-static PyObject *
-mapping_has_key(PyObject* self, PyObject *args)
-{
-    PyObject *context, *key;
-    if (!PyArg_ParseTuple(args, "OO", &context, &key)) {
-        return NULL;
-    }
-    return PyLong_FromLong(PyMapping_HasKey(context, key));
-}
-
-static PyObject *
-sequence_set_slice(PyObject* self, PyObject *args)
-{
-    PyObject *sequence, *obj;
-    Py_ssize_t i1, i2;
-    if (!PyArg_ParseTuple(args, "OnnO", &sequence, &i1, &i2, &obj)) {
-        return NULL;
-    }
-
-    int res = PySequence_SetSlice(sequence, i1, i2, obj);
-    if (res == -1) {
-        return NULL;
-    }
-    Py_RETURN_NONE;
-}
-
-static PyObject *
-sequence_del_slice(PyObject* self, PyObject *args)
-{
-    PyObject *sequence;
-    Py_ssize_t i1, i2;
-    if (!PyArg_ParseTuple(args, "Onn", &sequence, &i1, &i2)) {
-        return NULL;
-    }
-
-    int res = PySequence_DelSlice(sequence, i1, i2);
-    if (res == -1) {
-        return NULL;
-    }
-    Py_RETURN_NONE;
-}
-
-static PyObject *
 test_pythread_tss_key_state(PyObject *self, PyObject *args)
 {
     Py_tss_t tss_key = Py_tss_NEEDS_INIT;
@@ -2252,72 +2168,6 @@ negative_refcount(PyObject *self, PyObject *Py_UNUSED(args))
 #endif
 
 
-static PyObject *
-sequence_getitem(PyObject *self, PyObject *args)
-{
-    PyObject *seq;
-    Py_ssize_t i;
-    if (!PyArg_ParseTuple(args, "On", &seq, &i)) {
-        return NULL;
-    }
-    return PySequence_GetItem(seq, i);
-}
-
-
-static PyObject *
-sequence_setitem(PyObject *self, PyObject *args)
-{
-    Py_ssize_t i;
-    PyObject *seq, *val;
-    if (!PyArg_ParseTuple(args, "OnO", &seq, &i, &val)) {
-        return NULL;
-    }
-    if (PySequence_SetItem(seq, i, val)) {
-        return NULL;
-    }
-    Py_RETURN_NONE;
-}
-
-
-static PyObject *
-sequence_delitem(PyObject *self, PyObject *args)
-{
-    Py_ssize_t i;
-    PyObject *seq;
-    if (!PyArg_ParseTuple(args, "On", &seq, &i)) {
-        return NULL;
-    }
-    if (PySequence_DelItem(seq, i)) {
-        return NULL;
-    }
-    Py_RETURN_NONE;
-}
-
-static PyObject *
-hasattr_string(PyObject *self, PyObject* args)
-{
-    PyObject* obj;
-    PyObject* attr_name;
-
-    if (!PyArg_UnpackTuple(args, "hasattr_string", 2, 2, &obj, &attr_name)) {
-        return NULL;
-    }
-
-    if (!PyUnicode_Check(attr_name)) {
-        PyErr_SetString(PyExc_TypeError, "attribute name must a be string");
-        return PyErr_Occurred();
-    }
-
-    const char *name_str = PyUnicode_AsUTF8(attr_name);
-    if (PyObject_HasAttrString(obj, name_str)) {
-        Py_RETURN_TRUE;
-    }
-    else {
-        Py_RETURN_FALSE;
-    }
-}
-
-
 /* Functions for testing C calling conventions (METH_*) are named meth_*,
  * e.g. "meth_varargs" for METH_VARARGS.
  *
@@ -3459,23 +3309,12 @@ static PyMethodDef TestMethods[] = {
 #ifdef W_STOPCODE
     {"W_STOPCODE", py_w_stopcode, METH_VARARGS},
 #endif
-    {"get_mapping_keys", get_mapping_keys, METH_O},
-    {"get_mapping_values", get_mapping_values, METH_O},
-    {"get_mapping_items", get_mapping_items, METH_O},
-    {"test_mapping_has_key_string", test_mapping_has_key_string, METH_NOARGS},
-    {"mapping_has_key", mapping_has_key, METH_VARARGS},
-    {"sequence_set_slice", sequence_set_slice, METH_VARARGS},
-    {"sequence_del_slice", sequence_del_slice, METH_VARARGS},
     {"test_pythread_tss_key_state", test_pythread_tss_key_state, METH_VARARGS},
     {"hamt", new_hamt, METH_NOARGS},
     {"bad_get", _PyCFunction_CAST(bad_get), METH_FASTCALL},
 #ifdef Py_REF_DEBUG
     {"negative_refcount", negative_refcount, METH_NOARGS},
 #endif
-    {"sequence_getitem", sequence_getitem, METH_VARARGS},
-    {"sequence_setitem", sequence_setitem, METH_VARARGS},
-    {"sequence_delitem", sequence_delitem, METH_VARARGS},
-    {"hasattr_string", hasattr_string, METH_VARARGS},
     {"meth_varargs", meth_varargs, METH_VARARGS},
     {"meth_varargs_keywords", _PyCFunction_CAST(meth_varargs_keywords), METH_VARARGS|METH_KEYWORDS},
     {"meth_o", meth_o, METH_O},
@@ -4116,6 +3955,9 @@ PyInit__testcapi(void)
     if (_PyTestCapi_Init_Heaptype(m) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_Abstract(m) < 0) {
+        return NULL;
+    }
     if (_PyTestCapi_Init_Unicode(m) < 0) {
         return NULL;
     }
@@ -4143,6 +3985,9 @@ PyInit__testcapi(void)
     if (_PyTestCapi_Init_Float(m) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_Dict(m) < 0) {
+        return NULL;
+    }
     if (_PyTestCapi_Init_Structmember(m) < 0) {
         return NULL;
     }
diff --git a/PCbuild/_testcapi.vcxproj b/PCbuild/_testcapi.vcxproj
index 3db9426..1843b58 100644
--- a/PCbuild/_testcapi.vcxproj
+++ b/PCbuild/_testcapi.vcxproj
@@ -99,7 +99,9 @@
     <ClCompile Include="..\Modules\_testcapi\vectorcall_limited.c" />
     <ClCompile Include="..\Modules\_testcapi\heaptype.c" />
     <ClCompile Include="..\Modules\_testcapi\heaptype_relative.c" />
+    <ClCompile Include="..\Modules\_testcapi\abstract.c" />
     <ClCompile Include="..\Modules\_testcapi\unicode.c" />
+    <ClCompile Include="..\Modules\_testcapi\dict.c" />
     <ClCompile Include="..\Modules\_testcapi\pytime.c" />
     <ClCompile Include="..\Modules\_testcapi\datetime.c" />
     <ClCompile Include="..\Modules\_testcapi\docstring.c" />
@@ -131,4 +133,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/PCbuild/_testcapi.vcxproj.filters b/PCbuild/_testcapi.vcxproj.filters
index 8df4874..6132233 100644
--- a/PCbuild/_testcapi.vcxproj.filters
+++ b/PCbuild/_testcapi.vcxproj.filters
@@ -27,9 +27,15 @@
     <ClCompile Include="..\Modules\_testcapi\heaptype_relative.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Modules\_testcapi\abstract.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\Modules\_testcapi\unicode.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Modules\_testcapi\dict.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\Modules\_testcapi\pytime.c">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -75,4 +81,4 @@
       <Filter>Resource Files</Filter>
     </ResourceCompile>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>