Issue #25616: Tests for OrderedDict are extracted from test_collections

into separate file test_ordered_dict.

1 files changed, 691 insertions, 0 deletions

diff --git a/Lib/test/test_ordered_dict.py b/Lib/test/test_ordered_dict.py
new file mode 100644
index 0000000..e64c7e5
--- /dev/null
+++ b/Lib/test/test_ordered_dict.py
@@ -0,0 +1,691 @@
+import contextlib
+import copy
+import pickle
+from random import randrange, shuffle
+import sys
+import unittest
+from collections.abc import MutableMapping
+from test import mapping_tests, support
+
+
+py_coll = support.import_fresh_module('collections', blocked=['_collections'])
+c_coll = support.import_fresh_module('collections', fresh=['_collections'])
+
+
+@contextlib.contextmanager
+def replaced_module(name, replacement):
+    original_module = sys.modules[name]
+    sys.modules[name] = replacement
+    try:
+        yield
+    finally:
+        sys.modules[name] = original_module
+
+
+class OrderedDictTests:
+
+    def test_init(self):
+        OrderedDict = self.OrderedDict
+        with self.assertRaises(TypeError):
+            OrderedDict([('a', 1), ('b', 2)], None)                                 # too many args
+        pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)]
+        self.assertEqual(sorted(OrderedDict(dict(pairs)).items()), pairs)           # dict input
+        self.assertEqual(sorted(OrderedDict(**dict(pairs)).items()), pairs)         # kwds input
+        self.assertEqual(list(OrderedDict(pairs).items()), pairs)                   # pairs input
+        self.assertEqual(list(OrderedDict([('a', 1), ('b', 2), ('c', 9), ('d', 4)],
+                                          c=3, e=5).items()), pairs)                # mixed input
+
+        # make sure no positional args conflict with possible kwdargs
+        self.assertEqual(list(OrderedDict(self=42).items()), [('self', 42)])
+        self.assertEqual(list(OrderedDict(other=42).items()), [('other', 42)])
+        self.assertRaises(TypeError, OrderedDict, 42)
+        self.assertRaises(TypeError, OrderedDict, (), ())
+        self.assertRaises(TypeError, OrderedDict.__init__)
+
+        # Make sure that direct calls to __init__ do not clear previous contents
+        d = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 44), ('e', 55)])
+        d.__init__([('e', 5), ('f', 6)], g=7, d=4)
+        self.assertEqual(list(d.items()),
+            [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6), ('g', 7)])
+
+    def test_update(self):
+        OrderedDict = self.OrderedDict
+        with self.assertRaises(TypeError):
+            OrderedDict().update([('a', 1), ('b', 2)], None)                        # too many args
+        pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)]
+        od = OrderedDict()
+        od.update(dict(pairs))
+        self.assertEqual(sorted(od.items()), pairs)                                 # dict input
+        od = OrderedDict()
+        od.update(**dict(pairs))
+        self.assertEqual(sorted(od.items()), pairs)                                 # kwds input
+        od = OrderedDict()
+        od.update(pairs)
+        self.assertEqual(list(od.items()), pairs)                                   # pairs input
+        od = OrderedDict()
+        od.update([('a', 1), ('b', 2), ('c', 9), ('d', 4)], c=3, e=5)
+        self.assertEqual(list(od.items()), pairs)                                   # mixed input
+
+        # Issue 9137: Named argument called 'other' or 'self'
+        # shouldn't be treated specially.
+        od = OrderedDict()
+        od.update(self=23)
+        self.assertEqual(list(od.items()), [('self', 23)])
+        od = OrderedDict()
+        od.update(other={})
+        self.assertEqual(list(od.items()), [('other', {})])
+        od = OrderedDict()
+        od.update(red=5, blue=6, other=7, self=8)
+        self.assertEqual(sorted(list(od.items())),
+                         [('blue', 6), ('other', 7), ('red', 5), ('self', 8)])
+
+        # Make sure that direct calls to update do not clear previous contents
+        # add that updates items are not moved to the end
+        d = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 44), ('e', 55)])
+        d.update([('e', 5), ('f', 6)], g=7, d=4)
+        self.assertEqual(list(d.items()),
+            [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6), ('g', 7)])
+
+        self.assertRaises(TypeError, OrderedDict().update, 42)
+        self.assertRaises(TypeError, OrderedDict().update, (), ())
+        self.assertRaises(TypeError, OrderedDict.update)
+
+        self.assertRaises(TypeError, OrderedDict().update, 42)
+        self.assertRaises(TypeError, OrderedDict().update, (), ())
+        self.assertRaises(TypeError, OrderedDict.update)
+
+    def test_fromkeys(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict.fromkeys('abc')
+        self.assertEqual(list(od.items()), [(c, None) for c in 'abc'])
+        od = OrderedDict.fromkeys('abc', value=None)
+        self.assertEqual(list(od.items()), [(c, None) for c in 'abc'])
+        od = OrderedDict.fromkeys('abc', value=0)
+        self.assertEqual(list(od.items()), [(c, 0) for c in 'abc'])
+
+    def test_abc(self):
+        OrderedDict = self.OrderedDict
+        self.assertIsInstance(OrderedDict(), MutableMapping)
+        self.assertTrue(issubclass(OrderedDict, MutableMapping))
+
+    def test_clear(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od = OrderedDict(pairs)
+        self.assertEqual(len(od), len(pairs))
+        od.clear()
+        self.assertEqual(len(od), 0)
+
+    def test_delitem(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        od = OrderedDict(pairs)
+        del od['a']
+        self.assertNotIn('a', od)
+        with self.assertRaises(KeyError):
+            del od['a']
+        self.assertEqual(list(od.items()), pairs[:2] + pairs[3:])
+
+    def test_setitem(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict([('d', 1), ('b', 2), ('c', 3), ('a', 4), ('e', 5)])
+        od['c'] = 10           # existing element
+        od['f'] = 20           # new element
+        self.assertEqual(list(od.items()),
+                         [('d', 1), ('b', 2), ('c', 10), ('a', 4), ('e', 5), ('f', 20)])
+
+    def test_iterators(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od = OrderedDict(pairs)
+        self.assertEqual(list(od), [t[0] for t in pairs])
+        self.assertEqual(list(od.keys()), [t[0] for t in pairs])
+        self.assertEqual(list(od.values()), [t[1] for t in pairs])
+        self.assertEqual(list(od.items()), pairs)
+        self.assertEqual(list(reversed(od)),
+                         [t[0] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.keys())),
+                         [t[0] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.values())),
+                         [t[1] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.items())), list(reversed(pairs)))
+
+    def test_detect_deletion_during_iteration(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict.fromkeys('abc')
+        it = iter(od)
+        key = next(it)
+        del od[key]
+        with self.assertRaises(Exception):
+            # Note, the exact exception raised is not guaranteed
+            # The only guarantee that the next() will not succeed
+            next(it)
+
+    def test_sorted_iterators(self):
+        OrderedDict = self.OrderedDict
+        with self.assertRaises(TypeError):
+            OrderedDict([('a', 1), ('b', 2)], None)
+        pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)]
+        od = OrderedDict(pairs)
+        self.assertEqual(sorted(od), [t[0] for t in pairs])
+        self.assertEqual(sorted(od.keys()), [t[0] for t in pairs])
+        self.assertEqual(sorted(od.values()), [t[1] for t in pairs])
+        self.assertEqual(sorted(od.items()), pairs)
+        self.assertEqual(sorted(reversed(od)),
+                         sorted([t[0] for t in reversed(pairs)]))
+
+    def test_iterators_empty(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        empty = []
+        self.assertEqual(list(od), empty)
+        self.assertEqual(list(od.keys()), empty)
+        self.assertEqual(list(od.values()), empty)
+        self.assertEqual(list(od.items()), empty)
+        self.assertEqual(list(reversed(od)), empty)
+        self.assertEqual(list(reversed(od.keys())), empty)
+        self.assertEqual(list(reversed(od.values())), empty)
+        self.assertEqual(list(reversed(od.items())), empty)
+
+    def test_popitem(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od = OrderedDict(pairs)
+        while pairs:
+            self.assertEqual(od.popitem(), pairs.pop())
+        with self.assertRaises(KeyError):
+            od.popitem()
+        self.assertEqual(len(od), 0)
+
+    def test_popitem_last(self):
+        OrderedDict = self.OrderedDict
+        pairs = [(i, i) for i in range(30)]
+
+        obj = OrderedDict(pairs)
+        for i in range(8):
+            obj.popitem(True)
+        obj.popitem(True)
+        obj.popitem(last=True)
+        self.assertEqual(len(obj), 20)
+
+    def test_pop(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od = OrderedDict(pairs)
+        shuffle(pairs)
+        while pairs:
+            k, v = pairs.pop()
+            self.assertEqual(od.pop(k), v)
+        with self.assertRaises(KeyError):
+            od.pop('xyz')
+        self.assertEqual(len(od), 0)
+        self.assertEqual(od.pop(k, 12345), 12345)
+
+        # make sure pop still works when __missing__ is defined
+        class Missing(OrderedDict):
+            def __missing__(self, key):
+                return 0
+        m = Missing(a=1)
+        self.assertEqual(m.pop('b', 5), 5)
+        self.assertEqual(m.pop('a', 6), 1)
+        self.assertEqual(m.pop('a', 6), 6)
+        self.assertEqual(m.pop('a', default=6), 6)
+        with self.assertRaises(KeyError):
+            m.pop('a')
+
+    def test_equality(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od1 = OrderedDict(pairs)
+        od2 = OrderedDict(pairs)
+        self.assertEqual(od1, od2)          # same order implies equality
+        pairs = pairs[2:] + pairs[:2]
+        od2 = OrderedDict(pairs)
+        self.assertNotEqual(od1, od2)       # different order implies inequality
+        # comparison to regular dict is not order sensitive
+        self.assertEqual(od1, dict(od2))
+        self.assertEqual(dict(od2), od1)
+        # different length implied inequality
+        self.assertNotEqual(od1, OrderedDict(pairs[:-1]))
+
+    def test_copying(self):
+        OrderedDict = self.OrderedDict
+        # Check that ordered dicts are copyable, deepcopyable, picklable,
+        # and have a repr/eval round-trip
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        od = OrderedDict(pairs)
+        def check(dup):
+            msg = "\ncopy: %s\nod: %s" % (dup, od)
+            self.assertIsNot(dup, od, msg)
+            self.assertEqual(dup, od)
+            self.assertEqual(list(dup.items()), list(od.items()))
+            self.assertEqual(len(dup), len(od))
+            self.assertEqual(type(dup), type(od))
+        check(od.copy())
+        check(copy.copy(od))
+        check(copy.deepcopy(od))
+        # pickle directly pulls the module, so we have to fake it
+        with replaced_module('collections', self.module):
+            for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+                with self.subTest(proto=proto):
+                    check(pickle.loads(pickle.dumps(od, proto)))
+        check(eval(repr(od)))
+        update_test = OrderedDict()
+        update_test.update(od)
+        check(update_test)
+        check(OrderedDict(od))
+
+    def test_yaml_linkage(self):
+        OrderedDict = self.OrderedDict
+        # Verify that __reduce__ is setup in a way that supports PyYAML's dump() feature.
+        # In yaml, lists are native but tuples are not.
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        od = OrderedDict(pairs)
+        # yaml.dump(od) -->
+        # '!!python/object/apply:__main__.OrderedDict\n- - [a, 1]\n  - [b, 2]\n'
+        self.assertTrue(all(type(pair)==list for pair in od.__reduce__()[1]))
+
+    def test_reduce_not_too_fat(self):
+        OrderedDict = self.OrderedDict
+        # do not save instance dictionary if not needed
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        od = OrderedDict(pairs)
+        self.assertIsNone(od.__reduce__()[2])
+        od.x = 10
+        self.assertIsNotNone(od.__reduce__()[2])
+
+    def test_pickle_recursive(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        od[1] = od
+
+        # pickle directly pulls the module, so we have to fake it
+        with replaced_module('collections', self.module):
+            for proto in range(-1, pickle.HIGHEST_PROTOCOL + 1):
+                dup = pickle.loads(pickle.dumps(od, proto))
+                self.assertIsNot(dup, od)
+                self.assertEqual(list(dup.keys()), [1])
+                self.assertIs(dup[1], dup)
+
+    def test_repr(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict([('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)])
+        self.assertEqual(repr(od),
+            "OrderedDict([('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)])")
+        self.assertEqual(eval(repr(od)), od)
+        self.assertEqual(repr(OrderedDict()), "OrderedDict()")
+
+    def test_repr_recursive(self):
+        OrderedDict = self.OrderedDict
+        # See issue #9826
+        od = OrderedDict.fromkeys('abc')
+        od['x'] = od
+        self.assertEqual(repr(od),
+            "OrderedDict([('a', None), ('b', None), ('c', None), ('x', ...)])")
+
+    def test_setdefault(self):
+        OrderedDict = self.OrderedDict
+        pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
+        shuffle(pairs)
+        od = OrderedDict(pairs)
+        pair_order = list(od.items())
+        self.assertEqual(od.setdefault('a', 10), 3)
+        # make sure order didn't change
+        self.assertEqual(list(od.items()), pair_order)
+        self.assertEqual(od.setdefault('x', 10), 10)
+        # make sure 'x' is added to the end
+        self.assertEqual(list(od.items())[-1], ('x', 10))
+        self.assertEqual(od.setdefault('g', default=9), 9)
+
+        # make sure setdefault still works when __missing__ is defined
+        class Missing(OrderedDict):
+            def __missing__(self, key):
+                return 0
+        self.assertEqual(Missing().setdefault(5, 9), 9)
+
+    def test_reinsert(self):
+        OrderedDict = self.OrderedDict
+        # Given insert a, insert b, delete a, re-insert a,
+        # verify that a is now later than b.
+        od = OrderedDict()
+        od['a'] = 1
+        od['b'] = 2
+        del od['a']
+        self.assertEqual(list(od.items()), [('b', 2)])
+        od['a'] = 1
+        self.assertEqual(list(od.items()), [('b', 2), ('a', 1)])
+
+    def test_move_to_end(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict.fromkeys('abcde')
+        self.assertEqual(list(od), list('abcde'))
+        od.move_to_end('c')
+        self.assertEqual(list(od), list('abdec'))
+        od.move_to_end('c', 0)
+        self.assertEqual(list(od), list('cabde'))
+        od.move_to_end('c', 0)
+        self.assertEqual(list(od), list('cabde'))
+        od.move_to_end('e')
+        self.assertEqual(list(od), list('cabde'))
+        od.move_to_end('b', last=False)
+        self.assertEqual(list(od), list('bcade'))
+        with self.assertRaises(KeyError):
+            od.move_to_end('x')
+        with self.assertRaises(KeyError):
+            od.move_to_end('x', 0)
+
+    def test_move_to_end_issue25406(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict.fromkeys('abc')
+        od.move_to_end('c', last=False)
+        self.assertEqual(list(od), list('cab'))
+        od.move_to_end('a', last=False)
+        self.assertEqual(list(od), list('acb'))
+
+        od = OrderedDict.fromkeys('abc')
+        od.move_to_end('a')
+        self.assertEqual(list(od), list('bca'))
+        od.move_to_end('c')
+        self.assertEqual(list(od), list('bac'))
+
+    def test_sizeof(self):
+        OrderedDict = self.OrderedDict
+        # Wimpy test: Just verify the reported size is larger than a regular dict
+        d = dict(a=1)
+        od = OrderedDict(**d)
+        self.assertGreater(sys.getsizeof(od), sys.getsizeof(d))
+
+    def test_views(self):
+        OrderedDict = self.OrderedDict
+        # See http://bugs.python.org/issue24286
+        s = 'the quick brown fox jumped over a lazy dog yesterday before dawn'.split()
+        od = OrderedDict.fromkeys(s)
+        self.assertEqual(od.keys(), dict(od).keys())
+        self.assertEqual(od.items(), dict(od).items())
+
+    def test_override_update(self):
+        OrderedDict = self.OrderedDict
+        # Verify that subclasses can override update() without breaking __init__()
+        class MyOD(OrderedDict):
+            def update(self, *args, **kwds):
+                raise Exception()
+        items = [('a', 1), ('c', 3), ('b', 2)]
+        self.assertEqual(list(MyOD(items).items()), items)
+
+    def test_highly_nested(self):
+        # Issue 25395: crashes during garbage collection
+        OrderedDict = self.OrderedDict
+        obj = None
+        for _ in range(1000):
+            obj = OrderedDict([(None, obj)])
+        del obj
+        support.gc_collect()
+
+    def test_highly_nested_subclass(self):
+        # Issue 25395: crashes during garbage collection
+        OrderedDict = self.OrderedDict
+        deleted = []
+        class MyOD(OrderedDict):
+            def __del__(self):
+                deleted.append(self.i)
+        obj = None
+        for i in range(100):
+            obj = MyOD([(None, obj)])
+            obj.i = i
+        del obj
+        support.gc_collect()
+        self.assertEqual(deleted, list(reversed(range(100))))
+
+    def test_delitem_hash_collision(self):
+        OrderedDict = self.OrderedDict
+
+        class Key:
+            def __init__(self, hash):
+                self._hash = hash
+                self.value = str(id(self))
+            def __hash__(self):
+                return self._hash
+            def __eq__(self, other):
+                try:
+                    return self.value == other.value
+                except AttributeError:
+                    return False
+            def __repr__(self):
+                return self.value
+
+        def blocking_hash(hash):
+            # See the collision-handling in lookdict (in Objects/dictobject.c).
+            MINSIZE = 8
+            i = (hash & MINSIZE-1)
+            return (i << 2) + i + hash + 1
+
+        COLLIDING = 1
+
+        key = Key(COLLIDING)
+        colliding = Key(COLLIDING)
+        blocking = Key(blocking_hash(COLLIDING))
+
+        od = OrderedDict()
+        od[key] = ...
+        od[blocking] = ...
+        od[colliding] = ...
+        od['after'] = ...
+
+        del od[blocking]
+        del od[colliding]
+        self.assertEqual(list(od.items()), [(key, ...), ('after', ...)])
+
+    def test_issue24347(self):
+        OrderedDict = self.OrderedDict
+
+        class Key:
+            def __hash__(self):
+                return randrange(100000)
+
+        od = OrderedDict()
+        for i in range(100):
+            key = Key()
+            od[key] = i
+
+        # These should not crash.
+        with self.assertRaises(KeyError):
+            list(od.values())
+        with self.assertRaises(KeyError):
+            list(od.items())
+        with self.assertRaises(KeyError):
+            repr(od)
+        with self.assertRaises(KeyError):
+            od.copy()
+
+    def test_issue24348(self):
+        OrderedDict = self.OrderedDict
+
+        class Key:
+            def __hash__(self):
+                return 1
+
+        od = OrderedDict()
+        od[Key()] = 0
+        # This should not crash.
+        od.popitem()
+
+    def test_issue24667(self):
+        """
+        dict resizes after a certain number of insertion operations,
+        whether or not there were deletions that freed up slots in the
+        hash table.  During fast node lookup, OrderedDict must correctly
+        respond to all resizes, even if the current "size" is the same
+        as the old one.  We verify that here by forcing a dict resize
+        on a sparse odict and then perform an operation that should
+        trigger an odict resize (e.g. popitem).  One key aspect here is
+        that we will keep the size of the odict the same at each popitem
+        call.  This verifies that we handled the dict resize properly.
+        """
+        OrderedDict = self.OrderedDict
+
+        od = OrderedDict()
+        for c0 in '0123456789ABCDEF':
+            for c1 in '0123456789ABCDEF':
+                if len(od) == 4:
+                    # This should not raise a KeyError.
+                    od.popitem(last=False)
+                key = c0 + c1
+                od[key] = key
+
+    # Direct use of dict methods
+
+    def test_dict_setitem(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        dict.__setitem__(od, 'spam', 1)
+        self.assertNotIn('NULL', repr(od))
+
+    def test_dict_delitem(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        od['spam'] = 1
+        od['ham'] = 2
+        dict.__delitem__(od, 'spam')
+        with self.assertRaises(KeyError):
+            repr(od)
+
+    def test_dict_clear(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        od['spam'] = 1
+        od['ham'] = 2
+        dict.clear(od)
+        self.assertNotIn('NULL', repr(od))
+
+    def test_dict_pop(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        od['spam'] = 1
+        od['ham'] = 2
+        dict.pop(od, 'spam')
+        with self.assertRaises(KeyError):
+            repr(od)
+
+    def test_dict_popitem(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        od['spam'] = 1
+        od['ham'] = 2
+        dict.popitem(od)
+        with self.assertRaises(KeyError):
+            repr(od)
+
+    def test_dict_setdefault(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        dict.setdefault(od, 'spam', 1)
+        self.assertNotIn('NULL', repr(od))
+
+    def test_dict_update(self):
+        OrderedDict = self.OrderedDict
+        od = OrderedDict()
+        dict.update(od, [('spam', 1)])
+        self.assertNotIn('NULL', repr(od))
+
+
+class PurePythonOrderedDictTests(OrderedDictTests, unittest.TestCase):
+
+    module = py_coll
+    OrderedDict = py_coll.OrderedDict
+
+
+@unittest.skipUnless(c_coll, 'requires the C version of the collections module')
+class CPythonOrderedDictTests(OrderedDictTests, unittest.TestCase):
+
+    module = c_coll
+    OrderedDict = c_coll.OrderedDict
+
+    def test_key_change_during_iteration(self):
+        OrderedDict = self.OrderedDict
+
+        od = OrderedDict.fromkeys('abcde')
+        self.assertEqual(list(od), list('abcde'))
+        with self.assertRaises(RuntimeError):
+            for i, k in enumerate(od):
+                od.move_to_end(k)
+                self.assertLess(i, 5)
+        with self.assertRaises(RuntimeError):
+            for k in od:
+                od['f'] = None
+        with self.assertRaises(RuntimeError):
+            for k in od:
+                del od['c']
+        self.assertEqual(list(od), list('bdeaf'))
+
+
+class PurePythonOrderedDictSubclassTests(PurePythonOrderedDictTests):
+
+    module = py_coll
+    class OrderedDict(py_coll.OrderedDict):
+        pass
+
+
+class CPythonOrderedDictSubclassTests(CPythonOrderedDictTests):
+
+    module = c_coll
+    class OrderedDict(c_coll.OrderedDict):
+        pass
+
+
+class PurePythonGeneralMappingTests(mapping_tests.BasicTestMappingProtocol):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.type2test = py_coll.OrderedDict
+
+    def test_popitem(self):
+        d = self._empty_mapping()
+        self.assertRaises(KeyError, d.popitem)
+
+
+@unittest.skipUnless(c_coll, 'requires the C version of the collections module')
+class CPythonGeneralMappingTests(mapping_tests.BasicTestMappingProtocol):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.type2test = c_coll.OrderedDict
+
+    def test_popitem(self):
+        d = self._empty_mapping()
+        self.assertRaises(KeyError, d.popitem)
+
+
+class PurePythonSubclassMappingTests(mapping_tests.BasicTestMappingProtocol):
+
+    @classmethod
+    def setUpClass(cls):
+        class MyOrderedDict(py_coll.OrderedDict):
+            pass
+        cls.type2test = MyOrderedDict
+
+    def test_popitem(self):
+        d = self._empty_mapping()
+        self.assertRaises(KeyError, d.popitem)
+
+
+@unittest.skipUnless(c_coll, 'requires the C version of the collections module')
+class CPythonSubclassMappingTests(mapping_tests.BasicTestMappingProtocol):
+
+    @classmethod
+    def setUpClass(cls):
+        class MyOrderedDict(c_coll.OrderedDict):
+            pass
+        cls.type2test = MyOrderedDict
+
+    def test_popitem(self):
+        d = self._empty_mapping()
+        self.assertRaises(KeyError, d.popitem)
+
+
+if __name__ == "__main__":
+    unittest.main()