Merged revisions 70837,70864,70878,71004,71032,71043 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r70837 | gregory.p.smith | 2009-03-31 11:54:10 -0500 (Tue, 31 Mar 2009) | 9 lines

  The unittest.TestCase.assertEqual() now displays the differences in lists,
  tuples, dicts and sets on failure.

  Many new handy type and comparison specific assert* methods have been added
  that fail with error messages actually useful for debugging.  Contributed in
  by Google and completed with help from mfoord and GvR at PyCon 2009 sprints.

  Discussion lives in http://bugs.python.org/issue2578.
........
  r70864 | gregory.p.smith | 2009-03-31 14:03:28 -0500 (Tue, 31 Mar 2009) | 10 lines

  Rename the actual method definitions to the official assertFoo names.

  Adds unittests to make sure the old fail* names continue to work now
  and adds a comment that they are pending deprecation.

  Also adds a test to confirm that the plural Equals method variants
  continue to exist even though we're unlikely to deprecate those.

  http://bugs.python.org/issue2578
........
  r70878 | gregory.p.smith | 2009-03-31 14:59:14 -0500 (Tue, 31 Mar 2009) | 3 lines

  Issue an actual PendingDeprecationWarning for the TestCase.fail* methods.
  Document the deprecation.
........
  r71004 | benjamin.peterson | 2009-04-01 18:15:49 -0500 (Wed, 01 Apr 2009) | 1 line

  remove double underscores
........
  r71032 | michael.foord | 2009-04-01 22:20:38 -0500 (Wed, 01 Apr 2009) | 13 lines

  Better exception messages for unittest assert methods.

  - unittest.assertNotEqual() now uses the inequality operator (!=) instead
    of the equality operator.

  - Default assertTrue and assertFalse messages are now useful.

  - TestCase has a longMessage attribute. This defaults to False, but if set to True
    useful error messages are shown in addition to explicit messages passed to assert methods.

  Issue #5663
........
  r71043 | michael.foord | 2009-04-02 00:51:54 -0500 (Thu, 02 Apr 2009) | 7 lines

  Store the functions in the _type_equality_funcs as wrapped objects that are deep copyable.

  This allows for the deep copying of TestCase instances.

  Issue 5660
........

1 files changed, 544 insertions, 63 deletions

diff --git a/Lib/unittest.py b/Lib/unittest.py
index ade806c..16a8663 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -14,11 +14,11 @@ Simple usage:
 
     class IntegerArithmenticTestCase(unittest.TestCase):
         def testAdd(self):  ## test method names begin 'test*'
-            self.assertEquals((1 + 2), 3)
-            self.assertEquals(0 + 1, 1)
+            self.assertEqual((1 + 2), 3)
+            self.assertEqual(0 + 1, 1)
         def testMultiply(self):
-            self.assertEquals((0 * 10), 0)
-            self.assertEquals((5 * 8), 40)
+            self.assertEqual((0 * 10), 0)
+            self.assertEqual((5 * 8), 40)
 
     if __name__ == '__main__':
         unittest.main()
@@ -45,12 +45,16 @@ AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
 SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 '''
 
-import time
+import difflib
+import functools
+import os
+import pprint
+import re
 import sys
+import time
 import traceback
-import os
 import types
-import functools
+import warnings
 
 ##############################################################################
 # Exported classes and functions
@@ -143,7 +147,6 @@ def expectedFailure(func):
         raise _UnexpectedSuccess
     return wrapper
 
-
 __unittest = 1
 
 class TestResult(object):
@@ -239,10 +242,12 @@ class TestResult(object):
                 len(self.failures))
 
 
-class AssertRaisesContext(object):
+class _AssertRaisesContext(object):
+    """A context manager used to implement TestCase.assertRaises* methods."""
 
 
-    def __init__(self, expected, test_case, callable_obj=None):
+    def __init__(self, expected, test_case, callable_obj=None,
+                 expected_regexp=None):
         self.expected = expected
         self.failureException = test_case.failureException
         if callable_obj is not None:
@@ -252,6 +257,7 @@ class AssertRaisesContext(object):
                 self.obj_name = str(callable_obj)
         else:
             self.obj_name = None
+        self.expected_regex = expected_regexp
 
     def __enter__(self):
         pass
@@ -268,10 +274,30 @@ class AssertRaisesContext(object):
             else:
                 raise self.failureException("{0} not raised"
                     .format(exc_name))
-        if issubclass(exc_type, self.expected):
+        if not issubclass(exc_type, self.expected):
+            # let unexpected exceptions pass through
+            return False
+        if self.expected_regex is None:
             return True
-        # Let unexpected exceptions skip through
-        return False
+
+        expected_regexp = self.expected_regex
+        if isinstance(expected_regexp, (bytes, str)):
+            expected_regexp = re.compile(expected_regexp)
+        if not expected_regexp.search(str(exc_value)):
+            raise self.failureException('"%s" does not match "%s"' %
+                     (expected_regexp.pattern, str(exc_value)))
+        return True
+
+
+class _AssertWrapper(object):
+    """Wrap entries in the _type_equality_funcs registry to make them deep
+    copyable."""
+
+    def __init__(self, function):
+        self.function = function
+
+    def __deepcopy__(self, memo):
+        memo[id(self)] = self
 
 
 class TestCase(object):
@@ -302,6 +328,13 @@ class TestCase(object):
 
     failureException = AssertionError
 
+    # This attribute determines whether long messages (including repr of
+    # objects used in assert methods) will be printed on failure in *addition*
+    # to any explicit message passed.
+
+    longMessage = False
+
+
     def __init__(self, methodName='runTest'):
         """Create an instance of the class that will use the named test
            method when executed. Raises a ValueError if the instance does
@@ -315,6 +348,31 @@ class TestCase(object):
                   (self.__class__, methodName))
         self._testMethodDoc = testMethod.__doc__
 
+        # Map types to custom assertEqual functions that will compare
+        # instances of said type in more detail to generate a more useful
+        # error message.
+        self._type_equality_funcs = {}
+        self.addTypeEqualityFunc(dict, self.assertDictEqual)
+        self.addTypeEqualityFunc(list, self.assertListEqual)
+        self.addTypeEqualityFunc(tuple, self.assertTupleEqual)
+        self.addTypeEqualityFunc(set, self.assertSetEqual)
+        self.addTypeEqualityFunc(frozenset, self.assertSetEqual)
+
+    def addTypeEqualityFunc(self, typeobj, function):
+        """Add a type specific assertEqual style function to compare a type.
+
+        This method is for use by TestCase subclasses that need to register
+        their own type equality functions to provide nicer error messages.
+
+        Args:
+            typeobj: The data type to call this function on when both values
+                    are of the same type in assertEqual().
+            function: The callable taking two arguments and an optional
+                    msg= argument that raises self.failureException with a
+                    useful error message when the two arguments are not equal.
+        """
+        self._type_equality_funcs[typeobj] = _AssertWrapper(function)
+
     def setUp(self):
         "Hook method for setting up the test fixture before exercising it."
         pass
@@ -330,14 +388,22 @@ class TestCase(object):
         return TestResult()
 
     def shortDescription(self):
-        """Returns a one-line description of the test, or None if no
-        description has been provided.
+        """Returns both the test method name and first line of its docstring.
 
-        The default implementation of this method returns the first line of
-        the specified test method's docstring.
+        If no docstring is given, only returns the method name.
+
+        This method overrides unittest.TestCase.shortDescription(), which
+        only returns the first line of the docstring, obscuring the name
+        of the test upon failure.
         """
-        doc = self._testMethodDoc
-        return doc and doc.split("\n")[0].strip() or None
+        desc = str(self)
+        doc_first_line = None
+
+        if self._testMethodDoc:
+            doc_first_line = self._testMethodDoc.split("\n")[0].strip()
+        if doc_first_line:
+            desc = '\n'.join((desc, doc_first_line))
+        return desc
 
     def id(self):
         return "%s.%s" % (_strclass(self.__class__), self._testMethodName)
@@ -419,17 +485,36 @@ class TestCase(object):
         """Fail immediately, with the given message."""
         raise self.failureException(msg)
 
-    def failIf(self, expr, msg=None):
+    def assertFalse(self, expr, msg=None):
         "Fail the test if the expression is true."
         if expr:
+            msg = self._formatMessage(msg, "%r is not False" % expr)
             raise self.failureException(msg)
 
-    def failUnless(self, expr, msg=None):
+    def assertTrue(self, expr, msg=None):
         """Fail the test unless the expression is true."""
         if not expr:
+            msg = self._formatMessage(msg, "%r is not True" % expr)
             raise self.failureException(msg)
 
-    def failUnlessRaises(self, excClass, callableObj=None, *args, **kwargs):
+    def _formatMessage(self, msg, standardMsg):
+        """Honour the longMessage attribute when generating failure messages.
+        If longMessage is False this means:
+        * Use only an explicit message if it is provided
+        * Otherwise use the standard message for the assert
+
+        If longMessage is True:
+        * Use the standard message
+        * If an explicit message is provided, plus ' : ' and the explicit message
+        """
+        if not self.longMessage:
+            return msg or standardMsg
+        if msg is None:
+            return standardMsg
+        return standardMsg + ' : ' + msg
+
+
+    def assertRaises(self, excClass, callableObj=None, *args, **kwargs):
         """Fail unless an exception of class excClass is thrown
            by callableObj when invoked with arguments args and keyword
            arguments kwargs. If a different type of exception is
@@ -440,30 +525,62 @@ class TestCase(object):
            If called with callableObj omitted or None, will return a
            context object used like this::
 
-                with self.failUnlessRaises(some_error_class):
+                with self.assertRaises(some_error_class):
                     do_something()
         """
-        context = AssertRaisesContext(excClass, self, callableObj)
+        context = _AssertRaisesContext(excClass, self, callableObj)
         if callableObj is None:
             return context
         with context:
             callableObj(*args, **kwargs)
 
-    def failUnlessEqual(self, first, second, msg=None):
+    def _getAssertEqualityFunc(self, first, second):
+        """Get a detailed comparison function for the types of the two args.
+
+        Returns: A callable accepting (first, second, msg=None) that will
+        raise a failure exception if first != second with a useful human
+        readable error message for those types.
+        """
+        #
+        # NOTE(gregory.p.smith): I considered isinstance(first, type(second))
+        # and vice versa.  I opted for the conservative approach in case
+        # subclasses are not intended to be compared in detail to their super
+        # class instances using a type equality func.  This means testing
+        # subtypes won't automagically use the detailed comparison.  Callers
+        # should use their type specific assertSpamEqual method to compare
+        # subclasses if the detailed comparison is desired and appropriate.
+        # See the discussion in http://bugs.python.org/issue2578.
+        #
+        if type(first) is type(second):
+            asserter = self._type_equality_funcs.get(type(first))
+            if asserter is not None:
+                return asserter.function
+
+        return self._baseAssertEqual
+
+    def _baseAssertEqual(self, first, second, msg=None):
+        """The default assertEqual implementation, not type specific."""
+        if not first == second:
+            standardMsg = '%r != %r' % (first, second)
+            msg = self._formatMessage(msg, standardMsg)
+            raise self.failureException(msg)
+
+    def assertEqual(self, first, second, msg=None):
         """Fail if the two objects are unequal as determined by the '=='
            operator.
         """
-        if not first == second:
-            raise self.failureException(msg or '%r != %r' % (first, second))
+        assertion_func = self._getAssertEqualityFunc(first, second)
+        assertion_func(first, second, msg=msg)
 
-    def failIfEqual(self, first, second, msg=None):
+    def assertNotEqual(self, first, second, msg=None):
         """Fail if the two objects are equal as determined by the '=='
            operator.
         """
-        if first == second:
-            raise self.failureException(msg or '%r == %r' % (first, second))
+        if not first != second:
+            msg = self._formatMessage(msg, '%r == %r' % (first, second))
+            raise self.failureException(msg)
 
-    def failUnlessAlmostEqual(self, first, second, *, places=7, msg=None):
+    def assertAlmostEqual(self, first, second, *, places=7, msg=None):
         """Fail if the two objects are unequal as determined by their
            difference rounded to the given number of decimal places
            (default 7) and comparing to zero.
@@ -472,10 +589,11 @@ class TestCase(object):
            as significant digits (measured from the most signficant digit).
         """
         if round(abs(second-first), places) != 0:
-            raise self.failureException(
-                  msg or '%r != %r within %r places' % (first, second, places))
+            standardMsg = '%r != %r within %r places' % (first, second, places)
+            msg = self._formatMessage(msg, standardMsg)
+            raise self.failureException(msg)
 
-    def failIfAlmostEqual(self, first, second, *, places=7, msg=None):
+    def assertNotAlmostEqual(self, first, second, *, places=7, msg=None):
         """Fail if the two objects are equal as determined by their
            difference rounded to the given number of decimal places
            (default 7) and comparing to zero.
@@ -484,25 +602,388 @@ class TestCase(object):
            as significant digits (measured from the most signficant digit).
         """
         if round(abs(second-first), places) == 0:
-            raise self.failureException(
-                  msg or '%r == %r within %r places' % (first, second, places))
+            standardMsg = '%r == %r within %r places' % (first, second, places)
+            msg = self._formatMessage(msg, standardMsg)
+            raise self.failureException(msg)
 
     # Synonyms for assertion methods
 
-    assertEqual = assertEquals = failUnlessEqual
+    # The plurals are undocumented.  Keep them that way to discourage use.
+    # Do not add more.  Do not remove.
+    # Going through a deprecation cycle on these would annoy many people.
+    assertEquals = assertEqual
+    assertNotEquals = assertNotEqual
+    assertAlmostEquals = assertAlmostEqual
+    assertNotAlmostEquals = assertNotAlmostEqual
+    assert_ = assertTrue
+
+    # These fail* assertion method names are pending deprecation and will
+    # be a DeprecationWarning in 3.2; http://bugs.python.org/issue2578
+    def _deprecate(original_func):
+        def deprecated_func(*args, **kwargs):
+            warnings.warn(
+                'Please use {0} instead.'.format(original_func.__name__),
+                PendingDeprecationWarning, 2)
+            return original_func(*args, **kwargs)
+        return deprecated_func
+
+    failUnlessEqual = _deprecate(assertEqual)
+    failIfEqual = _deprecate(assertNotEqual)
+    failUnlessAlmostEqual = _deprecate(assertAlmostEqual)
+    failIfAlmostEqual = _deprecate(assertNotAlmostEqual)
+    failUnless = _deprecate(assertTrue)
+    failUnlessRaises = _deprecate(assertRaises)
+    failIf = _deprecate(assertFalse)
+
+    def assertSequenceEqual(self, seq1, seq2, msg=None, seq_type=None):
+        """An equality assertion for ordered sequences (like lists and tuples).
+
+        For the purposes of this function, a valid orderd sequence type is one
+        which can be indexed, has a length, and has an equality operator.
+
+        Args:
+            seq1: The first sequence to compare.
+            seq2: The second sequence to compare.
+            seq_type: The expected datatype of the sequences, or None if no
+                    datatype should be enforced.
+            msg: Optional message to use on failure instead of a list of
+                    differences.
+        """
+        if seq_type != None:
+            seq_type_name = seq_type.__name__
+            if not isinstance(seq1, seq_type):
+                raise self.failureException('First sequence is not a %s: %r'
+                                            % (seq_type_name, seq1))
+            if not isinstance(seq2, seq_type):
+                raise self.failureException('Second sequence is not a %s: %r'
+                                            % (seq_type_name, seq2))
+        else:
+            seq_type_name = "sequence"
+
+        differing = None
+        try:
+            len1 = len(seq1)
+        except (TypeError, NotImplementedError):
+            differing = 'First %s has no length.    Non-sequence?' % (
+                    seq_type_name)
+
+        if differing is None:
+            try:
+                len2 = len(seq2)
+            except (TypeError, NotImplementedError):
+                differing = 'Second %s has no length.    Non-sequence?' % (
+                        seq_type_name)
+
+        if differing is None:
+            if seq1 == seq2:
+                return
+
+            for i in range(min(len1, len2)):
+                try:
+                    item1 = seq1[i]
+                except (TypeError, IndexError, NotImplementedError):
+                    differing = ('Unable to index element %d of first %s\n' %
+                                 (i, seq_type_name))
+                    break
+
+                try:
+                    item2 = seq2[i]
+                except (TypeError, IndexError, NotImplementedError):
+                    differing = ('Unable to index element %d of second %s\n' %
+                                 (i, seq_type_name))
+                    break
+
+                if item1 != item2:
+                    differing = ('First differing element %d:\n%s\n%s\n' %
+                                 (i, item1, item2))
+                    break
+            else:
+                if (len1 == len2 and seq_type is None and
+                    type(seq1) != type(seq2)):
+                    # The sequences are the same, but have differing types.
+                    return
+                # A catch-all message for handling arbitrary user-defined
+                # sequences.
+                differing = '%ss differ:\n' % seq_type_name.capitalize()
+                if len1 > len2:
+                    differing = ('First %s contains %d additional '
+                                 'elements.\n' % (seq_type_name, len1 - len2))
+                    try:
+                        differing += ('First extra element %d:\n%s\n' %
+                                      (len2, seq1[len2]))
+                    except (TypeError, IndexError, NotImplementedError):
+                        differing += ('Unable to index element %d '
+                                      'of first %s\n' % (len2, seq_type_name))
+                elif len1 < len2:
+                    differing = ('Second %s contains %d additional '
+                                 'elements.\n' % (seq_type_name, len2 - len1))
+                    try:
+                        differing += ('First extra element %d:\n%s\n' %
+                                      (len1, seq2[len1]))
+                    except (TypeError, IndexError, NotImplementedError):
+                        differing += ('Unable to index element %d '
+                                      'of second %s\n' % (len1, seq_type_name))
+        standardMsg = differing + '\n'.join(difflib.ndiff(pprint.pformat(seq1).splitlines(),
+                                            pprint.pformat(seq2).splitlines()))
+        msg = self._formatMessage(msg, standardMsg)
+        self.fail(msg)
+
+    def assertListEqual(self, list1, list2, msg=None):
+        """A list-specific equality assertion.
+
+        Args:
+            list1: The first list to compare.
+            list2: The second list to compare.
+            msg: Optional message to use on failure instead of a list of
+                    differences.
+
+        """
+        self.assertSequenceEqual(list1, list2, msg, seq_type=list)
 
-    assertNotEqual = assertNotEquals = failIfEqual
+    def assertTupleEqual(self, tuple1, tuple2, msg=None):
+        """A tuple-specific equality assertion.
 
-    assertAlmostEqual = assertAlmostEquals = failUnlessAlmostEqual
+        Args:
+            tuple1: The first tuple to compare.
+            tuple2: The second tuple to compare.
+            msg: Optional message to use on failure instead of a list of
+                    differences.
+        """
+        self.assertSequenceEqual(tuple1, tuple2, msg, seq_type=tuple)
 
-    assertNotAlmostEqual = assertNotAlmostEquals = failIfAlmostEqual
+    def assertSetEqual(self, set1, set2, msg=None):
+        """A set-specific equality assertion.
 
-    assertRaises = failUnlessRaises
+        Args:
+            set1: The first set to compare.
+            set2: The second set to compare.
+            msg: Optional message to use on failure instead of a list of
+                    differences.
 
-    assert_ = assertTrue = failUnless
+        For more general containership equality, assertSameElements will work
+        with things other than sets.    This uses ducktyping to support
+        different types of sets, and is optimized for sets specifically
+        (parameters must support a difference method).
+        """
+        try:
+            difference1 = set1.difference(set2)
+        except TypeError as e:
+            self.fail('invalid type when attempting set difference: %s' % e)
+        except AttributeError as e:
+            self.fail('first argument does not support set difference: %s' % e)
 
-    assertFalse = failIf
+        try:
+            difference2 = set2.difference(set1)
+        except TypeError as e:
+            self.fail('invalid type when attempting set difference: %s' % e)
+        except AttributeError as e:
+            self.fail('second argument does not support set difference: %s' % e)
+
+        if not (difference1 or difference2):
+            return
+
+        lines = []
+        if difference1:
+            lines.append('Items in the first set but not the second:')
+            for item in difference1:
+                lines.append(repr(item))
+        if difference2:
+            lines.append('Items in the second set but not the first:')
+            for item in difference2:
+                lines.append(repr(item))
+
+        standardMsg = '\n'.join(lines)
+        self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertIn(self, member, container, msg=None):
+        """Just like self.assertTrue(a in b), but with a nicer default message."""
+        if member not in container:
+            standardMsg = '%r not found in %r' % (member, container)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertNotIn(self, member, container, msg=None):
+        """Just like self.assertTrue(a not in b), but with a nicer default message."""
+        if member in container:
+            standardMsg = '%r unexpectedly found in %r' % (member, container)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertDictEqual(self, d1, d2, msg=None):
+        self.assert_(isinstance(d1, dict), 'First argument is not a dictionary')
+        self.assert_(isinstance(d2, dict), 'Second argument is not a dictionary')
+
+        if d1 != d2:
+            standardMsg = ('\n' + '\n'.join(difflib.ndiff(
+                           pprint.pformat(d1).splitlines(),
+                           pprint.pformat(d2).splitlines())))
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertDictContainsSubset(self, expected, actual, msg=None):
+        """Checks whether actual is a superset of expected."""
+        missing = []
+        mismatched = []
+        for key, value in expected.items():
+            if key not in actual:
+                missing.append(key)
+            elif value != actual[key]:
+                mismatched.append('%s, expected: %s, actual: %s' % (key, value,                                                                                                       actual[key]))
+
+        if not (missing or mismatched):
+            return
+
+        standardMsg = ''
+        if missing:
+            standardMsg = 'Missing: %r' % ','.join(missing)
+        if mismatched:
+            if standardMsg:
+                standardMsg += '; '
+            standardMsg += 'Mismatched values: %s' % ','.join(mismatched)
+
+        self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertSameElements(self, expected_seq, actual_seq, msg=None):
+        """An unordered sequence specific comparison.
+
+        Raises with an error message listing which elements of expected_seq
+        are missing from actual_seq and vice versa if any.
+        """
+        try:
+            expected = set(expected_seq)
+            actual = set(actual_seq)
+            missing = list(expected.difference(actual))
+            unexpected = list(actual.difference(expected))
+            missing.sort()
+            unexpected.sort()
+        except TypeError:
+            # Fall back to slower list-compare if any of the objects are
+            # not hashable.
+            expected = list(expected_seq)
+            actual = list(actual_seq)
+            expected.sort()
+            actual.sort()
+            missing, unexpected = _SortedListDifference(expected, actual)
+        errors = []
+        if missing:
+            errors.append('Expected, but missing:\n    %r' % missing)
+        if unexpected:
+            errors.append('Unexpected, but present:\n    %r' % unexpected)
+        if errors:
+            standardMsg = '\n'.join(errors)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertMultiLineEqual(self, first, second, msg=None):
+        """Assert that two multi-line strings are equal."""
+        self.assert_(isinstance(first, str), (
+                'First argument is not a string'))
+        self.assert_(isinstance(second, str), (
+                'Second argument is not a string'))
+
+        if first != second:
+            standardMsg = '\n' + ''.join(difflib.ndiff(first.splitlines(True), second.splitlines(True)))
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertLess(self, a, b, msg=None):
+        """Just like self.assertTrue(a < b), but with a nicer default message."""
+        if not a < b:
+            standardMsg = '%r not less than %r' % (a, b)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertLessEqual(self, a, b, msg=None):
+        """Just like self.assertTrue(a <= b), but with a nicer default message."""
+        if not a <= b:
+            standardMsg = '%r not less than or equal to %r' % (a, b)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertGreater(self, a, b, msg=None):
+        """Just like self.assertTrue(a > b), but with a nicer default message."""
+        if not a > b:
+            standardMsg = '%r not greater than %r' % (a, b)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertGreaterEqual(self, a, b, msg=None):
+        """Just like self.assertTrue(a >= b), but with a nicer default message."""
+        if not a >= b:
+            standardMsg = '%r not greater than or equal to %r' % (a, b)
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertIsNone(self, obj, msg=None):
+        """Same as self.assertTrue(obj is None), with a nicer default message."""
+        if obj is not None:
+            standardMsg = '%r is not None' % obj
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertIsNotNone(self, obj, msg=None):
+        """Included for symmetry with assertIsNone."""
+        if obj is None:
+            standardMsg = 'unexpectedly None'
+            self.fail(self._formatMessage(msg, standardMsg))
+
+    def assertRaisesRegexp(self, expected_exception, expected_regexp,
+                           callable_obj=None, *args, **kwargs):
+        """Asserts that the message in a raised exception matches a regexp.
+
+        Args:
+            expected_exception: Exception class expected to be raised.
+            expected_regexp: Regexp (re pattern object or string) expected
+                    to be found in error message.
+            callable_obj: Function to be called.
+            args: Extra args.
+            kwargs: Extra kwargs.
+        """
+        context = _AssertRaisesContext(expected_exception, self, callable_obj,
+                                       expected_regexp)
+        if callable_obj is None:
+            return context
+        with context:
+            callable_obj(*args, **kwargs)
+
+    def assertRegexpMatches(self, text, expected_regex, msg=None):
+        if isinstance(expected_regex, (str, bytes)):
+            expected_regex = re.compile(expected_regex)
+        if not expected_regex.search(text):
+            msg = msg or "Regexp didn't match"
+            msg = '%s: %r not found in %r' % (msg, expected_regex.pattern, text)
+            raise self.failureException(msg)
+
+
+def _SortedListDifference(expected, actual):
+    """Finds elements in only one or the other of two, sorted input lists.
 
+    Returns a two-element tuple of lists.    The first list contains those
+    elements in the "expected" list but not in the "actual" list, and the
+    second contains those elements in the "actual" list but not in the
+    "expected" list.    Duplicate elements in either input list are ignored.
+    """
+    i = j = 0
+    missing = []
+    unexpected = []
+    while True:
+        try:
+            e = expected[i]
+            a = actual[j]
+            if e < a:
+                missing.append(e)
+                i += 1
+                while expected[i] == e:
+                    i += 1
+            elif e > a:
+                unexpected.append(a)
+                j += 1
+                while actual[j] == a:
+                    j += 1
+            else:
+                i += 1
+                try:
+                    while expected[i] == e:
+                        i += 1
+                finally:
+                    j += 1
+                    while actual[j] == a:
+                        j += 1
+        except IndexError:
+            missing.extend(expected[i:])
+            unexpected.extend(actual[j:])
+            break
+    return missing, unexpected
 
 
 class TestSuite(object):
@@ -611,52 +1092,52 @@ class FunctionTestCase(TestCase):
 
     def __init__(self, testFunc, setUp=None, tearDown=None, description=None):
         super(FunctionTestCase, self).__init__()
-        self.__setUpFunc = setUp
-        self.__tearDownFunc = tearDown
-        self.__testFunc = testFunc
-        self.__description = description
+        self._setUpFunc = setUp
+        self._tearDownFunc = tearDown
+        self._testFunc = testFunc
+        self._description = description
 
     def setUp(self):
-        if self.__setUpFunc is not None:
-            self.__setUpFunc()
+        if self._setUpFunc is not None:
+            self._setUpFunc()
 
     def tearDown(self):
-        if self.__tearDownFunc is not None:
-            self.__tearDownFunc()
+        if self._tearDownFunc is not None:
+            self._tearDownFunc()
 
     def runTest(self):
-        self.__testFunc()
+        self._testFunc()
 
     def id(self):
-        return self.__testFunc.__name__
+        return self._testFunc.__name__
 
     def __eq__(self, other):
         if not isinstance(other, self.__class__):
             return NotImplemented
 
-        return self.__setUpFunc == other.__setUpFunc and \
-               self.__tearDownFunc == other.__tearDownFunc and \
-               self.__testFunc == other.__testFunc and \
-               self.__description == other.__description
+        return self._setUpFunc == other._setUpFunc and \
+               self._tearDownFunc == other._tearDownFunc and \
+               self._testFunc == other._testFunc and \
+               self._description == other._description
 
     def __ne__(self, other):
         return not self == other
 
     def __hash__(self):
-        return hash((type(self), self.__setUpFunc, self.__tearDownFunc,
-                    self.__testFunc, self.__description))
+        return hash((type(self), self._setUpFunc, self._tearDownFunc,
+                     self._testFunc, self._description))
 
     def __str__(self):
         return "%s (%s)" % (_strclass(self.__class__),
                             self.__testFunc.__name__)
 
     def __repr__(self):
-        return "<%s testFunc=%s>" % (_strclass(self.__class__),
-                                     self.__testFunc)
+        return "<%s testFunc=%s>" % (_strclass(self.__class__), self._testFunc)
 
     def shortDescription(self):
-        if self.__description is not None: return self.__description
-        doc = self.__testFunc.__doc__
+        if self._description is not None:
+            return self._description
+        doc = self._testFunc.__doc__
         return doc and doc.split("\n")[0].strip() or None