Issue 10242: unittest.assertItemsEqual makes too many assumptions.

2 files changed, 28 insertions, 21 deletions

diff --git a/Lib/unittest/test/test_assertions.py b/Lib/unittest/test/test_assertions.py
index 91eb8bf..6a30db6 100644
--- a/Lib/unittest/test/test_assertions.py
+++ b/Lib/unittest/test/test_assertions.py
@@ -229,8 +229,8 @@ class TestLongMessage(unittest.TestCase):
                              "^Missing: 'key'$",
                              "^Missing: 'key' : oops$"])
 
-    def testAssertItemsEqual(self):
-        self.assertMessages('assertItemsEqual', ([], [None]),
+    def testassertCountEqual(self):
+        self.assertMessages('assertCountEqual', ([], [None]),
                             [r"\[None\]$", "^oops$",
                              r"\[None\]$",
                              r"\[None\] : oops$"])
diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py
index 07904d4..aa8cc37 100644
--- a/Lib/unittest/test/test_case.py
+++ b/Lib/unittest/test/test_case.py
@@ -672,46 +672,53 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing):
         else:
             self.fail('assertMultiLineEqual did not fail')
 
-    def testAssertItemsEqual(self):
+    def testassertCountEqual(self):
         a = object()
-        self.assertItemsEqual([1, 2, 3], [3, 2, 1])
-        self.assertItemsEqual(['foo', 'bar', 'baz'], ['bar', 'baz', 'foo'])
-        self.assertItemsEqual([a, a, 2, 2, 3], (a, 2, 3, a, 2))
-        self.assertItemsEqual([1, "2", "a", "a"], ["a", "2", True, "a"])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertCountEqual([1, 2, 3], [3, 2, 1])
+        self.assertCountEqual(['foo', 'bar', 'baz'], ['bar', 'baz', 'foo'])
+        self.assertCountEqual([a, a, 2, 2, 3], (a, 2, 3, a, 2))
+        self.assertCountEqual([1, "2", "a", "a"], ["a", "2", True, "a"])
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [1, 2] + [3] * 100, [1] * 100 + [2, 3])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [1, "2", "a", "a"], ["a", "2", True, 1])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [10], [10, 11])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [10, 11], [10])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [10, 11, 10], [10, 11])
 
         # Test that sequences of unhashable objects can be tested for sameness:
-        self.assertItemsEqual([[1, 2], [3, 4], 0], [False, [3, 4], [1, 2]])
+        self.assertCountEqual([[1, 2], [3, 4], 0], [False, [3, 4], [1, 2]])
 
         # hashable types, but not orderable
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [], [divmod, 'x', 1, 5j, 2j, frozenset()])
         # comparing dicts
-        self.assertItemsEqual([{'a': 1}, {'b': 2}], [{'b': 2}, {'a': 1}])
+        self.assertCountEqual([{'a': 1}, {'b': 2}], [{'b': 2}, {'a': 1}])
         # comparing heterogenous non-hashable sequences
-        self.assertItemsEqual([1, 'x', divmod, []], [divmod, [], 'x', 1])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertCountEqual([1, 'x', divmod, []], [divmod, [], 'x', 1])
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [], [divmod, [], 'x', 1, 5j, 2j, set()])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [[1]], [[2]])
 
         # Same elements, but not same sequence length
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [1, 1, 2], [2, 1])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [1, 1, "2", "a", "a"], ["2", "2", True, "a"])
-        self.assertRaises(self.failureException, self.assertItemsEqual,
+        self.assertRaises(self.failureException, self.assertCountEqual,
                           [1, {'b': 2}, None, True], [{'b': 2}, True, None])
 
+        # Same elements which don't reliably compare, in
+        # different order, see issue 10242
+        a = [{2,4}, {1,2}]
+        b = a[::-1]
+        self.assertCountEqual(a, b)
+
+
     def testAssertSetEqual(self):
         set1 = set()
         set2 = set()