Fix #19834: merge with 3.3.

28 files changed, 1671 insertions, 430 deletions

diff --git a/Lib/unittest/__main__.py b/Lib/unittest/__main__.py
index 798ebc0f53..2663178d3f 100644
--- a/Lib/unittest/__main__.py
+++ b/Lib/unittest/__main__.py
@@ -13,7 +13,6 @@ if sys.argv[0].endswith("__main__.py"):
 
 __unittest = True
 
-from .main import main, TestProgram, USAGE_AS_MAIN
-TestProgram.USAGE = USAGE_AS_MAIN
+from .main import main, TestProgram
 
 main(module=None)
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index f56af5574b..7ed932fafd 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -3,14 +3,16 @@
 import sys
 import functools
 import difflib
+import logging
 import pprint
 import re
 import warnings
 import collections
+import contextlib
 
 from . import result
 from .util import (strclass, safe_repr, _count_diff_all_purpose,
-                   _count_diff_hashable)
+                   _count_diff_hashable, _common_shorten_repr)
 
 __unittest = True
 
@@ -26,17 +28,11 @@ class SkipTest(Exception):
     instead of raising this directly.
     """
 
-class _ExpectedFailure(Exception):
+class _ShouldStop(Exception):
     """
-    Raise this when a test is expected to fail.
-
-    This is an implementation detail.
+    The test should stop.
     """
 
-    def __init__(self, exc_info):
-        super(_ExpectedFailure, self).__init__()
-        self.exc_info = exc_info
-
 class _UnexpectedSuccess(Exception):
     """
     The test was supposed to fail, but it didn't!
@@ -44,13 +40,40 @@ class _UnexpectedSuccess(Exception):
 
 
 class _Outcome(object):
-    def __init__(self):
+    def __init__(self, result=None):
+        self.expecting_failure = False
+        self.result = result
+        self.result_supports_subtests = hasattr(result, "addSubTest")
         self.success = True
-        self.skipped = None
-        self.unexpectedSuccess = None
+        self.skipped = []
         self.expectedFailure = None
         self.errors = []
-        self.failures = []
+
+    @contextlib.contextmanager
+    def testPartExecutor(self, test_case, isTest=False):
+        old_success = self.success
+        self.success = True
+        try:
+            yield
+        except KeyboardInterrupt:
+            raise
+        except SkipTest as e:
+            self.success = False
+            self.skipped.append((test_case, str(e)))
+        except _ShouldStop:
+            pass
+        except:
+            exc_info = sys.exc_info()
+            if self.expecting_failure:
+                self.expectedFailure = exc_info
+            else:
+                self.success = False
+                self.errors.append((test_case, exc_info))
+        else:
+            if self.result_supports_subtests and self.success:
+                self.errors.append((test_case, None))
+        finally:
+            self.success = self.success and old_success
 
 
 def _id(obj):
@@ -88,22 +111,26 @@ def skipUnless(condition, reason):
         return skip(reason)
     return _id
 
+def expectedFailure(test_item):
+    test_item.__unittest_expecting_failure__ = True
+    return test_item
 
-def expectedFailure(func):
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-        try:
-            func(*args, **kwargs)
-        except Exception:
-            raise _ExpectedFailure(sys.exc_info())
-        raise _UnexpectedSuccess
-    return wrapper
 
+class _BaseTestCaseContext:
 
-class _AssertRaisesBaseContext(object):
+    def __init__(self, test_case):
+        self.test_case = test_case
+
+    def _raiseFailure(self, standardMsg):
+        msg = self.test_case._formatMessage(self.msg, standardMsg)
+        raise self.test_case.failureException(msg)
+
+
+class _AssertRaisesBaseContext(_BaseTestCaseContext):
 
     def __init__(self, expected, test_case, callable_obj=None,
                  expected_regex=None):
+        _BaseTestCaseContext.__init__(self, test_case)
         self.expected = expected
         self.test_case = test_case
         if callable_obj is not None:
@@ -118,10 +145,6 @@ class _AssertRaisesBaseContext(object):
         self.expected_regex = expected_regex
         self.msg = None
 
-    def _raiseFailure(self, standardMsg):
-        msg = self.test_case._formatMessage(self.msg, standardMsg)
-        raise self.test_case.failureException(msg)
-
     def handle(self, name, callable_obj, args, kwargs):
         """
         If callable_obj is None, assertRaises/Warns is being used as a
@@ -135,7 +158,6 @@ class _AssertRaisesBaseContext(object):
             callable_obj(*args, **kwargs)
 
 
-
 class _AssertRaisesContext(_AssertRaisesBaseContext):
     """A context manager used to implement TestCase.assertRaises* methods."""
 
@@ -217,6 +239,74 @@ class _AssertWarnsContext(_AssertRaisesBaseContext):
             self._raiseFailure("{} not triggered".format(exc_name))
 
 
+
+_LoggingWatcher = collections.namedtuple("_LoggingWatcher",
+                                         ["records", "output"])
+
+
+class _CapturingHandler(logging.Handler):
+    """
+    A logging handler capturing all (raw and formatted) logging output.
+    """
+
+    def __init__(self):
+        logging.Handler.__init__(self)
+        self.watcher = _LoggingWatcher([], [])
+
+    def flush(self):
+        pass
+
+    def emit(self, record):
+        self.watcher.records.append(record)
+        msg = self.format(record)
+        self.watcher.output.append(msg)
+
+
+
+class _AssertLogsContext(_BaseTestCaseContext):
+    """A context manager used to implement TestCase.assertLogs()."""
+
+    LOGGING_FORMAT = "%(levelname)s:%(name)s:%(message)s"
+
+    def __init__(self, test_case, logger_name, level):
+        _BaseTestCaseContext.__init__(self, test_case)
+        self.logger_name = logger_name
+        if level:
+            self.level = logging._nameToLevel.get(level, level)
+        else:
+            self.level = logging.INFO
+        self.msg = None
+
+    def __enter__(self):
+        if isinstance(self.logger_name, logging.Logger):
+            logger = self.logger = self.logger_name
+        else:
+            logger = self.logger = logging.getLogger(self.logger_name)
+        formatter = logging.Formatter(self.LOGGING_FORMAT)
+        handler = _CapturingHandler()
+        handler.setFormatter(formatter)
+        self.watcher = handler.watcher
+        self.old_handlers = logger.handlers[:]
+        self.old_level = logger.level
+        self.old_propagate = logger.propagate
+        logger.handlers = [handler]
+        logger.setLevel(self.level)
+        logger.propagate = False
+        return handler.watcher
+
+    def __exit__(self, exc_type, exc_value, tb):
+        self.logger.handlers = self.old_handlers
+        self.logger.propagate = self.old_propagate
+        self.logger.setLevel(self.old_level)
+        if exc_type is not None:
+            # let unexpected exceptions pass through
+            return False
+        if len(self.watcher.records) == 0:
+            self._raiseFailure(
+                "no logs of level {} or higher triggered on {}"
+                .format(logging.getLevelName(self.level), self.logger.name))
+
+
 class TestCase(object):
     """A class whose instances are single test cases.
 
@@ -270,7 +360,7 @@ class TestCase(object):
            not have a method with the specified name.
         """
         self._testMethodName = methodName
-        self._outcomeForDoCleanups = None
+        self._outcome = None
         self._testMethodDoc = 'No test'
         try:
             testMethod = getattr(self, methodName)
@@ -283,6 +373,7 @@ class TestCase(object):
         else:
             self._testMethodDoc = testMethod.__doc__
         self._cleanups = []
+        self._subtest = None
 
         # Map types to custom assertEqual functions that will compare
         # instances of said type in more detail to generate a more useful
@@ -370,44 +461,80 @@ class TestCase(object):
         return "<%s testMethod=%s>" % \
                (strclass(self.__class__), self._testMethodName)
 
-    def _addSkip(self, result, reason):
+    def _addSkip(self, result, test_case, reason):
         addSkip = getattr(result, 'addSkip', None)
         if addSkip is not None:
-            addSkip(self, reason)
+            addSkip(test_case, reason)
         else:
             warnings.warn("TestResult has no addSkip method, skips not reported",
                           RuntimeWarning, 2)
+            result.addSuccess(test_case)
+
+    @contextlib.contextmanager
+    def subTest(self, msg=None, **params):
+        """Return a context manager that will return the enclosed block
+        of code in a subtest identified by the optional message and
+        keyword parameters.  A failure in the subtest marks the test
+        case as failed but resumes execution at the end of the enclosed
+        block, allowing further test code to be executed.
+        """
+        if not self._outcome.result_supports_subtests:
+            yield
+            return
+        parent = self._subtest
+        if parent is None:
+            params_map = collections.ChainMap(params)
+        else:
+            params_map = parent.params.new_child(params)
+        self._subtest = _SubTest(self, msg, params_map)
+        try:
+            with self._outcome.testPartExecutor(self._subtest, isTest=True):
+                yield
+            if not self._outcome.success:
+                result = self._outcome.result
+                if result is not None and result.failfast:
+                    raise _ShouldStop
+            elif self._outcome.expectedFailure:
+                # If the test is expecting a failure, we really want to
+                # stop now and register the expected failure.
+                raise _ShouldStop
+        finally:
+            self._subtest = parent
+
+    def _feedErrorsToResult(self, result, errors):
+        for test, exc_info in errors:
+            if isinstance(test, _SubTest):
+                result.addSubTest(test.test_case, test, exc_info)
+            elif exc_info is not None:
+                if issubclass(exc_info[0], self.failureException):
+                    result.addFailure(test, exc_info)
+                else:
+                    result.addError(test, exc_info)
+
+    def _addExpectedFailure(self, result, exc_info):
+        try:
+            addExpectedFailure = result.addExpectedFailure
+        except AttributeError:
+            warnings.warn("TestResult has no addExpectedFailure method, reporting as passes",
+                          RuntimeWarning)
             result.addSuccess(self)
+        else:
+            addExpectedFailure(self, exc_info)
 
-    def _executeTestPart(self, function, outcome, isTest=False):
+    def _addUnexpectedSuccess(self, result):
         try:
-            function()
-        except KeyboardInterrupt:
-            raise
-        except SkipTest as e:
-            outcome.success = False
-            outcome.skipped = str(e)
-        except _UnexpectedSuccess:
-            exc_info = sys.exc_info()
-            outcome.success = False
-            if isTest:
-                outcome.unexpectedSuccess = exc_info
-            else:
-                outcome.errors.append(exc_info)
-        except _ExpectedFailure:
-            outcome.success = False
-            exc_info = sys.exc_info()
-            if isTest:
-                outcome.expectedFailure = exc_info
-            else:
-                outcome.errors.append(exc_info)
-        except self.failureException:
-            outcome.success = False
-            outcome.failures.append(sys.exc_info())
-            exc_info = sys.exc_info()
-        except:
-            outcome.success = False
-            outcome.errors.append(sys.exc_info())
+            addUnexpectedSuccess = result.addUnexpectedSuccess
+        except AttributeError:
+            warnings.warn("TestResult has no addUnexpectedSuccess method, reporting as failure",
+                          RuntimeWarning)
+            # We need to pass an actual exception and traceback to addFailure,
+            # otherwise the legacy result can choke.
+            try:
+                raise _UnexpectedSuccess from None
+            except _UnexpectedSuccess:
+                result.addFailure(self, sys.exc_info())
+        else:
+            addUnexpectedSuccess(self)
 
     def run(self, result=None):
         orig_result = result
@@ -426,46 +553,38 @@ class TestCase(object):
             try:
                 skip_why = (getattr(self.__class__, '__unittest_skip_why__', '')
                             or getattr(testMethod, '__unittest_skip_why__', ''))
-                self._addSkip(result, skip_why)
+                self._addSkip(result, self, skip_why)
             finally:
                 result.stopTest(self)
             return
+        expecting_failure = getattr(testMethod,
+                                    "__unittest_expecting_failure__", False)
         try:
-            outcome = _Outcome()
-            self._outcomeForDoCleanups = outcome
+            outcome = _Outcome(result)
+            self._outcome = outcome
 
-            self._executeTestPart(self.setUp, outcome)
+            with outcome.testPartExecutor(self):
+                self.setUp()
             if outcome.success:
-                self._executeTestPart(testMethod, outcome, isTest=True)
-                self._executeTestPart(self.tearDown, outcome)
+                outcome.expecting_failure = expecting_failure
+                with outcome.testPartExecutor(self, isTest=True):
+                    testMethod()
+                outcome.expecting_failure = False
+                with outcome.testPartExecutor(self):
+                    self.tearDown()
 
             self.doCleanups()
+            for test, reason in outcome.skipped:
+                self._addSkip(result, test, reason)
+            self._feedErrorsToResult(result, outcome.errors)
             if outcome.success:
-                result.addSuccess(self)
-            else:
-                if outcome.skipped is not None:
-                    self._addSkip(result, outcome.skipped)
-                for exc_info in outcome.errors:
-                    result.addError(self, exc_info)
-                for exc_info in outcome.failures:
-                    result.addFailure(self, exc_info)
-                if outcome.unexpectedSuccess is not None:
-                    addUnexpectedSuccess = getattr(result, 'addUnexpectedSuccess', None)
-                    if addUnexpectedSuccess is not None:
-                        addUnexpectedSuccess(self)
+                if expecting_failure:
+                    if outcome.expectedFailure:
+                        self._addExpectedFailure(result, outcome.expectedFailure)
                     else:
-                        warnings.warn("TestResult has no addUnexpectedSuccess method, reporting as failures",
-                                      RuntimeWarning)
-                        result.addFailure(self, outcome.unexpectedSuccess)
-
-                if outcome.expectedFailure is not None:
-                    addExpectedFailure = getattr(result, 'addExpectedFailure', None)
-                    if addExpectedFailure is not None:
-                        addExpectedFailure(self, outcome.expectedFailure)
-                    else:
-                        warnings.warn("TestResult has no addExpectedFailure method, reporting as passes",
-                                      RuntimeWarning)
-                        result.addSuccess(self)
+                        self._addUnexpectedSuccess(result)
+                else:
+                    result.addSuccess(self)
             return result
         finally:
             result.stopTest(self)
@@ -477,11 +596,11 @@ class TestCase(object):
     def doCleanups(self):
         """Execute all cleanup functions. Normally called for you after
         tearDown."""
-        outcome = self._outcomeForDoCleanups or _Outcome()
+        outcome = self._outcome or _Outcome()
         while self._cleanups:
             function, args, kwargs = self._cleanups.pop()
-            part = lambda: function(*args, **kwargs)
-            self._executeTestPart(part, outcome)
+            with outcome.testPartExecutor(self):
+                function(*args, **kwargs)
 
         # return this for backwards compatibility
         # even though we no longer us it internally
@@ -600,6 +719,28 @@ class TestCase(object):
         context = _AssertWarnsContext(expected_warning, self, callable_obj)
         return context.handle('assertWarns', callable_obj, args, kwargs)
 
+    def assertLogs(self, logger=None, level=None):
+        """Fail unless a log message of level *level* or higher is emitted
+        on *logger_name* or its children.  If omitted, *level* defaults to
+        INFO and *logger* defaults to the root logger.
+
+        This method must be used as a context manager, and will yield
+        a recording object with two attributes: `output` and `records`.
+        At the end of the context manager, the `output` attribute will
+        be a list of the matching formatted log messages and the
+        `records` attribute will be a list of the corresponding LogRecord
+        objects.
+
+        Example::
+
+            with self.assertLogs('foo', level='INFO') as cm:
+                logging.getLogger('foo').info('first message')
+                logging.getLogger('foo.bar').error('second message')
+            self.assertEqual(cm.output, ['INFO:foo:first message',
+                                         'ERROR:foo.bar:second message'])
+        """
+        return _AssertLogsContext(self, logger, level)
+
     def _getAssertEqualityFunc(self, first, second):
         """Get a detailed comparison function for the types of the two args.
 
@@ -629,7 +770,7 @@ class TestCase(object):
     def _baseAssertEqual(self, first, second, msg=None):
         """The default assertEqual implementation, not type specific."""
         if not first == second:
-            standardMsg = '%s != %s' % (safe_repr(first), safe_repr(second))
+            standardMsg = '%s != %s' % _common_shorten_repr(first, second)
             msg = self._formatMessage(msg, standardMsg)
             raise self.failureException(msg)
 
@@ -764,14 +905,9 @@ class TestCase(object):
             if seq1 == seq2:
                 return
 
-            seq1_repr = safe_repr(seq1)
-            seq2_repr = safe_repr(seq2)
-            if len(seq1_repr) > 30:
-                seq1_repr = seq1_repr[:30] + '...'
-            if len(seq2_repr) > 30:
-                seq2_repr = seq2_repr[:30] + '...'
-            elements = (seq_type_name.capitalize(), seq1_repr, seq2_repr)
-            differing = '%ss differ: %s != %s\n' % elements
+            differing = '%ss differ: %s != %s\n' % (
+                    (seq_type_name.capitalize(),) +
+                    _common_shorten_repr(seq1, seq2))
 
             for i in range(min(len1, len2)):
                 try:
@@ -929,7 +1065,7 @@ class TestCase(object):
         self.assertIsInstance(d2, dict, 'Second argument is not a dictionary')
 
         if d1 != d2:
-            standardMsg = '%s != %s' % (safe_repr(d1, True), safe_repr(d2, True))
+            standardMsg = '%s != %s' % _common_shorten_repr(d1, d2)
             diff = ('\n' + '\n'.join(difflib.ndiff(
                            pprint.pformat(d1).splitlines(),
                            pprint.pformat(d2).splitlines())))
@@ -1013,8 +1149,7 @@ class TestCase(object):
             if len(firstlines) == 1 and first.strip('\r\n') == first:
                 firstlines = [first + '\n']
                 secondlines = [second + '\n']
-            standardMsg = '%s != %s' % (safe_repr(first, True),
-                                        safe_repr(second, True))
+            standardMsg = '%s != %s' % _common_shorten_repr(first, second)
             diff = '\n' + ''.join(difflib.ndiff(firstlines, secondlines))
             standardMsg = self._truncateMessage(standardMsg, diff)
             self.fail(self._formatMessage(msg, standardMsg))
@@ -1212,3 +1347,39 @@ class FunctionTestCase(TestCase):
             return self._description
         doc = self._testFunc.__doc__
         return doc and doc.split("\n")[0].strip() or None
+
+
+class _SubTest(TestCase):
+
+    def __init__(self, test_case, message, params):
+        super().__init__()
+        self._message = message
+        self.test_case = test_case
+        self.params = params
+        self.failureException = test_case.failureException
+
+    def runTest(self):
+        raise NotImplementedError("subtests cannot be run directly")
+
+    def _subDescription(self):
+        parts = []
+        if self._message:
+            parts.append("[{}]".format(self._message))
+        if self.params:
+            params_desc = ', '.join(
+                "{}={!r}".format(k, v)
+                for (k, v) in sorted(self.params.items()))
+            parts.append("({})".format(params_desc))
+        return " ".join(parts) or '(<subtest>)'
+
+    def id(self):
+        return "{} {}".format(self.test_case.id(), self._subDescription())
+
+    def shortDescription(self):
+        """Returns a one-line description of the subtest, or None if no
+        description has been provided.
+        """
+        return self.test_case.shortDescription()
+
+    def __str__(self):
+        return "{} {}".format(self.test_case, self._subDescription())
diff --git a/Lib/unittest/loader.py b/Lib/unittest/loader.py
index 9ab26c1efb..808c50eb66 100644
--- a/Lib/unittest/loader.py
+++ b/Lib/unittest/loader.py
@@ -34,6 +34,14 @@ def _make_failed_test(classname, methodname, exception, suiteClass):
     TestClass = type(classname, (case.TestCase,), attrs)
     return suiteClass((TestClass(methodname),))
 
+def _make_skipped_test(methodname, exception, suiteClass):
+    @case.skip(str(exception))
+    def testSkipped(self):
+        pass
+    attrs = {methodname: testSkipped}
+    TestClass = type("ModuleSkipped", (case.TestCase,), attrs)
+    return suiteClass((TestClass(methodname),))
+
 def _jython_aware_splitext(path):
     if path.lower().endswith('$py.class'):
         return path[:-9]
@@ -53,8 +61,9 @@ class TestLoader(object):
     def loadTestsFromTestCase(self, testCaseClass):
         """Return a suite of all tests cases contained in testCaseClass"""
         if issubclass(testCaseClass, suite.TestSuite):
-            raise TypeError("Test cases should not be derived from TestSuite." \
-                                " Maybe you meant to derive from TestCase?")
+            raise TypeError("Test cases should not be derived from "
+                            "TestSuite. Maybe you meant to derive from "
+                            "TestCase?")
         testCaseNames = self.getTestCaseNames(testCaseClass)
         if not testCaseNames and hasattr(testCaseClass, 'runTest'):
             testCaseNames = ['runTest']
@@ -169,6 +178,9 @@ class TestLoader(object):
         The pattern is deliberately not stored as a loader attribute so that
         packages can continue discovery themselves. top_level_dir is stored so
         load_tests does not need to pass this argument in to loader.discover().
+
+        Paths are sorted before being imported to ensure reproducible execution
+        order even on filesystems with non-alphabetical ordering like ext3/4.
         """
         set_implicit_top = False
         if top_level_dir is None and self._top_level_dir is not None:
@@ -189,6 +201,8 @@ class TestLoader(object):
         self._top_level_dir = top_level_dir
 
         is_not_importable = False
+        is_namespace = False
+        tests = []
         if os.path.isdir(os.path.abspath(start_dir)):
             start_dir = os.path.abspath(start_dir)
             if start_dir != top_level_dir:
@@ -202,15 +216,52 @@ class TestLoader(object):
             else:
                 the_module = sys.modules[start_dir]
                 top_part = start_dir.split('.')[0]
-                start_dir = os.path.abspath(os.path.dirname((the_module.__file__)))
+                try:
+                    start_dir = os.path.abspath(
+                       os.path.dirname((the_module.__file__)))
+                except AttributeError:
+                    # look for namespace packages
+                    try:
+                        spec = the_module.__spec__
+                    except AttributeError:
+                        spec = None
+
+                    if spec and spec.loader is None:
+                        if spec.submodule_search_locations is not None:
+                            is_namespace = True
+
+                            for path in the_module.__path__:
+                                if (not set_implicit_top and
+                                    not path.startswith(top_level_dir)):
+                                    continue
+                                self._top_level_dir = \
+                                    (path.split(the_module.__name__
+                                         .replace(".", os.path.sep))[0])
+                                tests.extend(self._find_tests(path,
+                                                              pattern,
+                                                              namespace=True))
+                    elif the_module.__name__ in sys.builtin_module_names:
+                        # builtin module
+                        raise TypeError('Can not use builtin modules '
+                                        'as dotted module names') from None
+                    else:
+                        raise TypeError(
+                            'don\'t know how to discover from {!r}'
+                            .format(the_module)) from None
+
                 if set_implicit_top:
-                    self._top_level_dir = self._get_directory_containing_module(top_part)
-                    sys.path.remove(top_level_dir)
+                    if not is_namespace:
+                        self._top_level_dir = \
+                           self._get_directory_containing_module(top_part)
+                        sys.path.remove(top_level_dir)
+                    else:
+                        sys.path.remove(top_level_dir)
 
         if is_not_importable:
             raise ImportError('Start directory is not importable: %r' % start_dir)
 
-        tests = list(self._find_tests(start_dir, pattern))
+        if not is_namespace:
+            tests = list(self._find_tests(start_dir, pattern))
         return self.suiteClass(tests)
 
     def _get_directory_containing_module(self, module_name):
@@ -243,9 +294,9 @@ class TestLoader(object):
         # override this method to use alternative matching strategy
         return fnmatch(path, pattern)
 
-    def _find_tests(self, start_dir, pattern):
+    def _find_tests(self, start_dir, pattern, namespace=False):
         """Used by discovery. Yields test suites it loads."""
-        paths = os.listdir(start_dir)
+        paths = sorted(os.listdir(start_dir))
 
         for path in paths:
             full_path = os.path.join(start_dir, path)
@@ -259,6 +310,8 @@ class TestLoader(object):
                 name = self._get_name_from_path(full_path)
                 try:
                     module = self._get_module_from_name(name)
+                except case.SkipTest as e:
+                    yield _make_skipped_test(name, e, self.suiteClass)
                 except:
                     yield _make_failed_import_test(name, self.suiteClass)
                 else:
@@ -274,7 +327,8 @@ class TestLoader(object):
                         raise ImportError(msg % (mod_name, module_dir, expected_dir))
                     yield self.loadTestsFromModule(module)
             elif os.path.isdir(full_path):
-                if not os.path.isfile(os.path.join(full_path, '__init__.py')):
+                if (not namespace and
+                    not os.path.isfile(os.path.join(full_path, '__init__.py'))):
                     continue
 
                 load_tests = None
@@ -291,8 +345,8 @@ class TestLoader(object):
                         # tests loaded from package file
                         yield tests
                     # recurse into the package
-                    for test in self._find_tests(full_path, pattern):
-                        yield test
+                    yield from self._find_tests(full_path, pattern,
+                                                namespace=namespace)
                 else:
                     try:
                         yield load_tests(self, tests, pattern)
diff --git a/Lib/unittest/main.py b/Lib/unittest/main.py
index ead64936a0..180df8676e 100644
--- a/Lib/unittest/main.py
+++ b/Lib/unittest/main.py
@@ -1,7 +1,7 @@
 """Unittest main program"""
 
 import sys
-import optparse
+import argparse
 import os
 
 from . import loader, runner
@@ -9,53 +9,20 @@ from .signals import installHandler
 
 __unittest = True
 
-FAILFAST     = "  -f, --failfast   Stop on first failure\n"
-CATCHBREAK   = "  -c, --catch      Catch control-C and display results\n"
-BUFFEROUTPUT = "  -b, --buffer     Buffer stdout and stderr during test runs\n"
-
-USAGE_AS_MAIN = """\
-Usage: %(progName)s [options] [tests]
-
-Options:
-  -h, --help       Show this message
-  -v, --verbose    Verbose output
-  -q, --quiet      Minimal output
-%(failfast)s%(catchbreak)s%(buffer)s
+MAIN_EXAMPLES = """\
 Examples:
-  %(progName)s test_module               - run tests from test_module
-  %(progName)s module.TestClass          - run tests from module.TestClass
-  %(progName)s module.Class.test_method  - run specified test method
-
-[tests] can be a list of any number of test modules, classes and test
-methods.
-
-Alternative Usage: %(progName)s discover [options]
-
-Options:
-  -v, --verbose    Verbose output
-%(failfast)s%(catchbreak)s%(buffer)s  -s directory     Directory to start discovery ('.' default)
-  -p pattern       Pattern to match test files ('test*.py' default)
-  -t directory     Top level directory of project (default to
-                   start directory)
-
-For test discovery all test modules must be importable from the top
-level directory of the project.
+  %(prog)s test_module               - run tests from test_module
+  %(prog)s module.TestClass          - run tests from module.TestClass
+  %(prog)s module.Class.test_method  - run specified test method
 """
 
-USAGE_FROM_MODULE = """\
-Usage: %(progName)s [options] [test] [...]
-
-Options:
-  -h, --help       Show this message
-  -v, --verbose    Verbose output
-  -q, --quiet      Minimal output
-%(failfast)s%(catchbreak)s%(buffer)s
+MODULE_EXAMPLES = """\
 Examples:
-  %(progName)s                               - run default set of tests
-  %(progName)s MyTestSuite                   - run suite 'MyTestSuite'
-  %(progName)s MyTestCase.testSomething      - run MyTestCase.testSomething
-  %(progName)s MyTestCase                    - run all 'test*' test methods
-                                               in MyTestCase
+  %(prog)s                           - run default set of tests
+  %(prog)s MyTestSuite               - run suite 'MyTestSuite'
+  %(prog)s MyTestCase.testSomething  - run MyTestCase.testSomething
+  %(prog)s MyTestCase                - run all 'test*' test methods
+                                       in MyTestCase
 """
 
 def _convert_name(name):
@@ -82,10 +49,11 @@ class TestProgram(object):
     """A command-line program that runs a set of tests; this is primarily
        for making test modules conveniently executable.
     """
-    USAGE = USAGE_FROM_MODULE
-
     # defaults for testing
+    module=None
+    verbosity = 1
     failfast = catchbreak = buffer = progName = warnings = None
+    _discovery_parser = None
 
     def __init__(self, module='__main__', defaultTest=None, argv=None,
                     testRunner=None, testLoader=loader.defaultTestLoader,
@@ -127,44 +95,47 @@ class TestProgram(object):
     def usageExit(self, msg=None):
         if msg:
             print(msg)
-        usage = {'progName': self.progName, 'catchbreak': '', 'failfast': '',
-                 'buffer': ''}
-        if self.failfast != False:
-            usage['failfast'] = FAILFAST
-        if self.catchbreak != False:
-            usage['catchbreak'] = CATCHBREAK
-        if self.buffer != False:
-            usage['buffer'] = BUFFEROUTPUT
-        print(self.USAGE % usage)
+        if self._discovery_parser is None:
+            self._initArgParsers()
+        self._print_help()
         sys.exit(2)
 
-    def parseArgs(self, argv):
-        if ((len(argv) > 1 and argv[1].lower() == 'discover') or
-            (len(argv) == 1 and self.module is None)):
-            self._do_discovery(argv[2:])
-            return
-
-        parser = self._getOptParser()
-        options, args = parser.parse_args(argv[1:])
-        self._setAttributesFromOptions(options)
+    def _print_help(self, *args, **kwargs):
+        if self.module is None:
+            print(self._main_parser.format_help())
+            print(MAIN_EXAMPLES % {'prog': self.progName})
+            self._discovery_parser.print_help()
+        else:
+            print(self._main_parser.format_help())
+            print(MODULE_EXAMPLES % {'prog': self.progName})
 
-        if len(args) == 0 and self.module is None:
-            # this allows "python -m unittest -v" to still work for
-            # test discovery. This means -c / -b / -v / -f options will
-            # be handled twice, which is harmless but not ideal.
-            self._do_discovery(argv[1:])
-            return
+    def parseArgs(self, argv):
+        self._initArgParsers()
+        if self.module is None:
+            if len(argv) > 1 and argv[1].lower() == 'discover':
+                self._do_discovery(argv[2:])
+                return
+            self._main_parser.parse_args(argv[1:], self)
+            if not self.tests:
+                # this allows "python -m unittest -v" to still work for
+                # test discovery.
+                self._do_discovery([])
+                return
+        else:
+            self._main_parser.parse_args(argv[1:], self)
 
-        if len(args) == 0 and self.defaultTest is None:
-            # createTests will load tests from self.module
-            self.testNames = None
-        elif len(args) > 0:
-            self.testNames = _convert_names(args)
+        if self.tests:
+            self.testNames = _convert_names(self.tests)
             if __name__ == '__main__':
                 # to support python -m unittest ...
                 self.module = None
-        else:
+        elif self.defaultTest is None:
+            # createTests will load tests from self.module
+            self.testNames = None
+        elif isinstance(self.defaultTest, str):
             self.testNames = (self.defaultTest,)
+        else:
+            self.testNames = list(self.defaultTest)
         self.createTests()
 
     def createTests(self):
@@ -174,76 +145,84 @@ class TestProgram(object):
             self.test = self.testLoader.loadTestsFromNames(self.testNames,
                                                            self.module)
 
-    def _getOptParser(self):
-        import optparse
-        parser = optparse.OptionParser()
-        parser.prog = self.progName
-        parser.add_option('-v', '--verbose', dest='verbose', default=False,
-                          help='Verbose output', action='store_true')
-        parser.add_option('-q', '--quiet', dest='quiet', default=False,
-                          help='Quiet output', action='store_true')
+    def _initArgParsers(self):
+        parent_parser = self._getParentArgParser()
+        self._main_parser = self._getMainArgParser(parent_parser)
+        self._discovery_parser = self._getDiscoveryArgParser(parent_parser)
 
-        if self.failfast != False:
-            parser.add_option('-f', '--failfast', dest='failfast', default=False,
-                              help='Stop on first fail or error',
-                              action='store_true')
-        if self.catchbreak != False:
-            parser.add_option('-c', '--catch', dest='catchbreak', default=False,
-                              help='Catch ctrl-C and display results so far',
-                              action='store_true')
-        if self.buffer != False:
-            parser.add_option('-b', '--buffer', dest='buffer', default=False,
-                              help='Buffer stdout and stderr during tests',
-                              action='store_true')
-        return parser
+    def _getParentArgParser(self):
+        parser = argparse.ArgumentParser(add_help=False)
+
+        parser.add_argument('-v', '--verbose', dest='verbosity',
+                            action='store_const', const=2,
+                            help='Verbose output')
+        parser.add_argument('-q', '--quiet', dest='verbosity',
+                            action='store_const', const=0,
+                            help='Quiet output')
 
-    def _setAttributesFromOptions(self, options):
-        # only set options from the parsing here
-        # if they weren't set explicitly in the constructor
         if self.failfast is None:
-            self.failfast = options.failfast
+            parser.add_argument('-f', '--failfast', dest='failfast',
+                                action='store_true',
+                                help='Stop on first fail or error')
+            self.failfast = False
         if self.catchbreak is None:
-            self.catchbreak = options.catchbreak
+            parser.add_argument('-c', '--catch', dest='catchbreak',
+                                action='store_true',
+                                help='Catch ctrl-C and display results so far')
+            self.catchbreak = False
         if self.buffer is None:
-            self.buffer = options.buffer
-
-        if options.verbose:
-            self.verbosity = 2
-        elif options.quiet:
-            self.verbosity = 0
+            parser.add_argument('-b', '--buffer', dest='buffer',
+                                action='store_true',
+                                help='Buffer stdout and stderr during tests')
+            self.buffer = False
 
-    def _addDiscoveryOptions(self, parser):
-        parser.add_option('-s', '--start-directory', dest='start', default='.',
-                          help="Directory to start discovery ('.' default)")
-        parser.add_option('-p', '--pattern', dest='pattern', default='test*.py',
-                          help="Pattern to match tests ('test*.py' default)")
-        parser.add_option('-t', '--top-level-directory', dest='top', default=None,
-                          help='Top level directory of project (defaults to start directory)')
-
-    def _do_discovery(self, argv, Loader=None):
-        if Loader is None:
-            Loader = lambda: self.testLoader
+        return parser
 
-        # handle command line args for test discovery
-        self.progName = '%s discover' % self.progName
-        parser = self._getOptParser()
-        self._addDiscoveryOptions(parser)
+    def _getMainArgParser(self, parent):
+        parser = argparse.ArgumentParser(parents=[parent])
+        parser.prog = self.progName
+        parser.print_help = self._print_help
 
-        options, args = parser.parse_args(argv)
-        if len(args) > 3:
-            self.usageExit()
+        parser.add_argument('tests', nargs='*',
+                            help='a list of any number of test modules, '
+                            'classes and test methods.')
 
-        for name, value in zip(('start', 'pattern', 'top'), args):
-            setattr(options, name, value)
+        return parser
 
-        self._setAttributesFromOptions(options)
+    def _getDiscoveryArgParser(self, parent):
+        parser = argparse.ArgumentParser(parents=[parent])
+        parser.prog = '%s discover' % self.progName
+        parser.epilog = ('For test discovery all test modules must be '
+                         'importable from the top level directory of the '
+                         'project.')
+
+        parser.add_argument('-s', '--start-directory', dest='start',
+                            help="Directory to start discovery ('.' default)")
+        parser.add_argument('-p', '--pattern', dest='pattern',
+                            help="Pattern to match tests ('test*.py' default)")
+        parser.add_argument('-t', '--top-level-directory', dest='top',
+                            help='Top level directory of project (defaults to '
+                                 'start directory)')
+        for arg in ('start', 'pattern', 'top'):
+            parser.add_argument(arg, nargs='?',
+                                default=argparse.SUPPRESS,
+                                help=argparse.SUPPRESS)
 
-        start_dir = options.start
-        pattern = options.pattern
-        top_level_dir = options.top
+        return parser
 
-        loader = Loader()
-        self.test = loader.discover(start_dir, pattern, top_level_dir)
+    def _do_discovery(self, argv, Loader=None):
+        self.start = '.'
+        self.pattern = 'test*.py'
+        self.top = None
+        if argv is not None:
+            # handle command line args for test discovery
+            if self._discovery_parser is None:
+                # for testing
+                self._initArgParsers()
+            self._discovery_parser.parse_args(argv, self)
+
+        loader = self.testLoader if Loader is None else Loader()
+        self.test = loader.discover(self.start, self.pattern, self.top)
 
     def runTests(self):
         if self.catchbreak:
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 073869a1f1..dc5c033739 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -27,7 +27,7 @@ __version__ = '1.0'
 import inspect
 import pprint
 import sys
-from functools import wraps
+from functools import wraps, partial
 
 
 BaseExceptions = (BaseException,)
@@ -66,55 +66,45 @@ DescriptorTypes = (
 )
 
 
-def _getsignature(func, skipfirst, instance=False):
-    if isinstance(func, type) and not instance:
+def _get_signature_object(func, as_instance, eat_self):
+    """
+    Given an arbitrary, possibly callable object, try to create a suitable
+    signature object.
+    Return a (reduced func, signature) tuple, or None.
+    """
+    if isinstance(func, type) and not as_instance:
+        # If it's a type and should be modelled as a type, use __init__.
         try:
             func = func.__init__
         except AttributeError:
-            return
-        skipfirst = True
+            return None
+        # Skip the `self` argument in __init__
+        eat_self = True
     elif not isinstance(func, FunctionTypes):
-        # for classes where instance is True we end up here too
+        # If we really want to model an instance of the passed type,
+        # __call__ should be looked up, not __init__.
         try:
             func = func.__call__
         except AttributeError:
-            return
-
+            return None
+    if eat_self:
+        sig_func = partial(func, None)
+    else:
+        sig_func = func
     try:
-        argspec = inspect.getfullargspec(func)
-    except TypeError:
-        # C function / method, possibly inherited object().__init__
-        return
-
-    regargs, varargs, varkw, defaults, kwonly, kwonlydef, ann = argspec
-
-
-    # instance methods and classmethods need to lose the self argument
-    if getattr(func, '__self__', None) is not None:
-        regargs = regargs[1:]
-    if skipfirst:
-        # this condition and the above one are never both True - why?
-        regargs = regargs[1:]
-
-    signature = inspect.formatargspec(
-        regargs, varargs, varkw, defaults,
-        kwonly, kwonlydef, ann, formatvalue=lambda value: "")
-    return signature[1:-1], func
+        return func, inspect.signature(sig_func)
+    except ValueError:
+        # Certain callable types are not supported by inspect.signature()
+        return None
 
 
 def _check_signature(func, mock, skipfirst, instance=False):
-    if not _callable(func):
+    sig = _get_signature_object(func, instance, skipfirst)
+    if sig is None:
         return
-
-    result = _getsignature(func, skipfirst, instance)
-    if result is None:
-        return
-    signature, func = result
-
-    # can't use self because "self" is common as an argument name
-    # unfortunately even not in the first place
-    src = "lambda _mock_self, %s: None" % signature
-    checksig = eval(src, {})
+    func, sig = sig
+    def checksig(_mock_self, *args, **kwargs):
+        sig.bind(*args, **kwargs)
     _copy_func_details(func, checksig)
     type(mock)._mock_check_sig = checksig
 
@@ -166,15 +156,12 @@ def _set_signature(mock, original, instance=False):
         return
 
     skipfirst = isinstance(original, type)
-    result = _getsignature(original, skipfirst, instance)
+    result = _get_signature_object(original, instance, skipfirst)
     if result is None:
-        # was a C function (e.g. object().__init__ ) that can't be mocked
         return
-
-    signature, func = result
-
-    src = "lambda %s: None" % signature
-    checksig = eval(src, {})
+    func, sig = result
+    def checksig(*args, **kwargs):
+        sig.bind(*args, **kwargs)
     _copy_func_details(func, checksig)
 
     name = original.__name__
@@ -368,7 +355,7 @@ class NonCallableMock(Base):
     def __init__(
             self, spec=None, wraps=None, name=None, spec_set=None,
             parent=None, _spec_state=None, _new_name='', _new_parent=None,
-            **kwargs
+            _spec_as_instance=False, _eat_self=None, **kwargs
         ):
         if _new_parent is None:
             _new_parent = parent
@@ -382,8 +369,10 @@ class NonCallableMock(Base):
         if spec_set is not None:
             spec = spec_set
             spec_set = True
+        if _eat_self is None:
+            _eat_self = parent is not None
 
-        self._mock_add_spec(spec, spec_set)
+        self._mock_add_spec(spec, spec_set, _spec_as_instance, _eat_self)
 
         __dict__['_mock_children'] = {}
         __dict__['_mock_wraps'] = wraps
@@ -428,20 +417,26 @@ class NonCallableMock(Base):
         self._mock_add_spec(spec, spec_set)
 
 
-    def _mock_add_spec(self, spec, spec_set):
+    def _mock_add_spec(self, spec, spec_set, _spec_as_instance=False,
+                       _eat_self=False):
         _spec_class = None
+        _spec_signature = None
 
         if spec is not None and not _is_list(spec):
             if isinstance(spec, type):
                 _spec_class = spec
             else:
                 _spec_class = _get_class(spec)
+            res = _get_signature_object(spec,
+                                        _spec_as_instance, _eat_self)
+            _spec_signature = res and res[1]
 
             spec = dir(spec)
 
         __dict__ = self.__dict__
         __dict__['_spec_class'] = _spec_class
         __dict__['_spec_set'] = spec_set
+        __dict__['_spec_signature'] = _spec_signature
         __dict__['_mock_methods'] = spec
 
 
@@ -695,7 +690,6 @@ class NonCallableMock(Base):
         self._mock_children[name] = _deleted
 
 
-
     def _format_mock_call_signature(self, args, kwargs):
         name = self._mock_name or 'mock'
         return _format_call_signature(name, args, kwargs)
@@ -711,6 +705,28 @@ class NonCallableMock(Base):
         return message % (expected_string, actual_string)
 
 
+    def _call_matcher(self, _call):
+        """
+        Given a call (or simply a (args, kwargs) tuple), return a
+        comparison key suitable for matching with other calls.
+        This is a best effort method which relies on the spec's signature,
+        if available, or falls back on the arguments themselves.
+        """
+        sig = self._spec_signature
+        if sig is not None:
+            if len(_call) == 2:
+                name = ''
+                args, kwargs = _call
+            else:
+                name, args, kwargs = _call
+            try:
+                return name, sig.bind(*args, **kwargs)
+            except TypeError as e:
+                return e.with_traceback(None)
+        else:
+            return _call
+
+
     def assert_called_with(_mock_self, *args, **kwargs):
         """assert that the mock was called with the specified arguments.
 
@@ -721,9 +737,14 @@ class NonCallableMock(Base):
             expected = self._format_mock_call_signature(args, kwargs)
             raise AssertionError('Expected call: %s\nNot called' % (expected,))
 
-        if self.call_args != (args, kwargs):
+        def _error_message():
             msg = self._format_mock_failure_message(args, kwargs)
-            raise AssertionError(msg)
+            return msg
+        expected = self._call_matcher((args, kwargs))
+        actual = self._call_matcher(self.call_args)
+        if expected != actual:
+            cause = expected if isinstance(expected, Exception) else None
+            raise AssertionError(_error_message()) from cause
 
 
     def assert_called_once_with(_mock_self, *args, **kwargs):
@@ -747,18 +768,21 @@ class NonCallableMock(Base):
 
         If `any_order` is True then the calls can be in any order, but
         they must all appear in `mock_calls`."""
+        expected = [self._call_matcher(c) for c in calls]
+        cause = expected if isinstance(expected, Exception) else None
+        all_calls = _CallList(self._call_matcher(c) for c in self.mock_calls)
         if not any_order:
-            if calls not in self.mock_calls:
+            if expected not in all_calls:
                 raise AssertionError(
                     'Calls not found.\nExpected: %r\n'
                     'Actual: %r' % (calls, self.mock_calls)
-                )
+                ) from cause
             return
 
-        all_calls = list(self.mock_calls)
+        all_calls = list(all_calls)
 
         not_found = []
-        for kall in calls:
+        for kall in expected:
             try:
                 all_calls.remove(kall)
             except ValueError:
@@ -766,7 +790,7 @@ class NonCallableMock(Base):
         if not_found:
             raise AssertionError(
                 '%r not all found in call list' % (tuple(not_found),)
-            )
+            ) from cause
 
 
     def assert_any_call(self, *args, **kwargs):
@@ -775,12 +799,14 @@ class NonCallableMock(Base):
         The assert passes if the mock has *ever* been called, unlike
         `assert_called_with` and `assert_called_once_with` that only pass if
         the call is the most recent one."""
-        kall = call(*args, **kwargs)
-        if kall not in self.call_args_list:
+        expected = self._call_matcher((args, kwargs))
+        actual = [self._call_matcher(c) for c in self.call_args_list]
+        if expected not in actual:
+            cause = expected if isinstance(expected, Exception) else None
             expected_string = self._format_mock_call_signature(args, kwargs)
             raise AssertionError(
                 '%s call not found' % expected_string
-            )
+            ) from cause
 
 
     def _get_child_mock(self, **kw):
@@ -850,11 +876,12 @@ class CallableMixin(Base):
         self = _mock_self
         self.called = True
         self.call_count += 1
-        self.call_args = _Call((args, kwargs), two=True)
-        self.call_args_list.append(_Call((args, kwargs), two=True))
-
         _new_name = self._mock_new_name
         _new_parent = self._mock_new_parent
+
+        _call = _Call((args, kwargs), two=True)
+        self.call_args = _call
+        self.call_args_list.append(_call)
         self.mock_calls.append(_Call(('', args, kwargs)))
 
         seen = set()
@@ -909,8 +936,6 @@ class CallableMixin(Base):
                 return result
 
             ret_val = effect(*args, **kwargs)
-            if ret_val is DEFAULT:
-                ret_val = self.return_value
 
         if (self._mock_wraps is not None and
              self._mock_return_value is DEFAULT):
@@ -2030,6 +2055,8 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
     elif spec is None:
         # None we mock with a normal mock without a spec
         _kwargs = {}
+    if _kwargs and instance:
+        _kwargs['_spec_as_instance'] = True
 
     _kwargs.update(kwargs)
 
@@ -2096,10 +2123,12 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
             if isinstance(spec, FunctionTypes):
                 parent = mock.mock
 
+            skipfirst = _must_skip(spec, entry, is_type)
+            kwargs['_eat_self'] = skipfirst
             new = MagicMock(parent=parent, name=entry, _new_name=entry,
-                            _new_parent=parent, **kwargs)
+                            _new_parent=parent,
+                            **kwargs)
             mock._mock_children[entry] = new
-            skipfirst = _must_skip(spec, entry, is_type)
             _check_signature(original, new, skipfirst=skipfirst)
 
         # so functions created with _set_signature become instance attributes,
@@ -2113,6 +2142,10 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
 
 
 def _must_skip(spec, entry, is_type):
+    """
+    Return whether we should skip the first argument on spec's `entry`
+    attribute.
+    """
     if not isinstance(spec, type):
         if entry in getattr(spec, '__dict__', {}):
             # instance attribute - shouldn't skip
@@ -2125,7 +2158,12 @@ def _must_skip(spec, entry, is_type):
             continue
         if isinstance(result, (staticmethod, classmethod)):
             return False
-        return is_type
+        elif isinstance(getattr(result, '__get__', None), MethodWrapperTypes):
+            # Normal method => skip if looked up on type
+            # (if looked up on instance, self is already skipped)
+            return is_type
+        else:
+            return False
 
     # shouldn't get here unless function is a dynamically provided attribute
     # XXXX untested behaviour
@@ -2159,9 +2197,31 @@ FunctionTypes = (
     type(ANY.__eq__),
 )
 
+MethodWrapperTypes = (
+    type(ANY.__eq__.__get__),
+)
+
 
 file_spec = None
 
+def _iterate_read_data(read_data):
+    # Helper for mock_open:
+    # Retrieve lines from read_data via a generator so that separate calls to
+    # readline, read, and readlines are properly interleaved
+    data_as_list = ['{}\n'.format(l) for l in read_data.split('\n')]
+
+    if data_as_list[-1] == '\n':
+        # If the last line ended in a newline, the list comprehension will have an
+        # extra entry that's just a newline.  Remove this.
+        data_as_list = data_as_list[:-1]
+    else:
+        # If there wasn't an extra newline by itself, then the file being
+        # emulated doesn't have a newline to end the last line  remove the
+        # newline that our naive format() added
+        data_as_list[-1] = data_as_list[-1][:-1]
+
+    for line in data_as_list:
+        yield line
 
 def mock_open(mock=None, read_data=''):
     """
@@ -2172,9 +2232,27 @@ def mock_open(mock=None, read_data=''):
     default) then a `MagicMock` will be created for you, with the API limited
     to methods or attributes available on standard file handles.
 
-    `read_data` is a string for the `read` method of the file handle to return.
-    This is an empty string by default.
+    `read_data` is a string for the `read` methoddline`, and `readlines` of the
+    file handle to return.  This is an empty string by default.
     """
+    def _readlines_side_effect(*args, **kwargs):
+        if handle.readlines.return_value is not None:
+            return handle.readlines.return_value
+        return list(_data)
+
+    def _read_side_effect(*args, **kwargs):
+        if handle.read.return_value is not None:
+            return handle.read.return_value
+        return ''.join(_data)
+
+    def _readline_side_effect():
+        if handle.readline.return_value is not None:
+            while True:
+                yield handle.readline.return_value
+        for line in _data:
+            yield line
+
+
     global file_spec
     if file_spec is None:
         import _io
@@ -2184,9 +2262,18 @@ def mock_open(mock=None, read_data=''):
         mock = MagicMock(name='open', spec=open)
 
     handle = MagicMock(spec=file_spec)
-    handle.write.return_value = None
     handle.__enter__.return_value = handle
-    handle.read.return_value = read_data
+
+    _data = _iterate_read_data(read_data)
+
+    handle.write.return_value = None
+    handle.read.return_value = None
+    handle.readline.return_value = None
+    handle.readlines.return_value = None
+
+    handle.read.side_effect = _read_side_effect
+    handle.readline.side_effect = _readline_side_effect()
+    handle.readlines.side_effect = _readlines_side_effect
 
     mock.return_value = handle
     return mock
diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index 97e5426927..f3f4b676a3 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -121,6 +121,22 @@ class TestResult(object):
         self.failures.append((test, self._exc_info_to_string(err, test)))
         self._mirrorOutput = True
 
+    @failfast
+    def addSubTest(self, test, subtest, err):
+        """Called at the end of a subtest.
+        'err' is None if the subtest ended successfully, otherwise it's a
+        tuple of values as returned by sys.exc_info().
+        """
+        # By default, we don't do anything with successful subtests, but
+        # more sophisticated test results might want to record them.
+        if err is not None:
+            if issubclass(err[0], test.failureException):
+                errors = self.failures
+            else:
+                errors = self.errors
+            errors.append((subtest, self._exc_info_to_string(err, test)))
+            self._mirrorOutput = True
+
     def addSuccess(self, test):
         "Called when a test has completed successfully"
         pass
diff --git a/Lib/unittest/suite.py b/Lib/unittest/suite.py
index cde5d385ed..ca82765b9c 100644
--- a/Lib/unittest/suite.py
+++ b/Lib/unittest/suite.py
@@ -16,6 +16,8 @@ def _call_if_exists(parent, attr):
 class BaseTestSuite(object):
     """A simple test suite that doesn't provide class or module shared fixtures.
     """
+    _cleanup = True
+
     def __init__(self, tests=()):
         self._tests = []
         self.addTests(tests)
@@ -57,12 +59,22 @@ class BaseTestSuite(object):
             self.addTest(test)
 
     def run(self, result):
-        for test in self:
+        for index, test in enumerate(self):
             if result.shouldStop:
                 break
             test(result)
+            if self._cleanup:
+                self._removeTestAtIndex(index)
         return result
 
+    def _removeTestAtIndex(self, index):
+        """Stop holding a reference to the TestCase at index."""
+        try:
+            self._tests[index] = None
+        except TypeError:
+            # support for suite implementations that have overriden self._test
+            pass
+
     def __call__(self, *args, **kwds):
         return self.run(*args, **kwds)
 
@@ -87,7 +99,7 @@ class TestSuite(BaseTestSuite):
         if getattr(result, '_testRunEntered', False) is False:
             result._testRunEntered = topLevel = True
 
-        for test in self:
+        for index, test in enumerate(self):
             if result.shouldStop:
                 break
 
@@ -106,6 +118,9 @@ class TestSuite(BaseTestSuite):
             else:
                 test.debug()
 
+            if self._cleanup:
+                self._removeTestAtIndex(index)
+
         if topLevel:
             self._tearDownPreviousClass(None, result)
             self._handleModuleTearDown(result)
diff --git a/Lib/unittest/test/__main__.py b/Lib/unittest/test/__main__.py
new file mode 100644
index 0000000000..44d0591e84
--- /dev/null
+++ b/Lib/unittest/test/__main__.py
@@ -0,0 +1,18 @@
+import os
+import unittest
+
+
+def load_tests(loader, standard_tests, pattern):
+    # top level directory cached on loader instance
+    this_dir = os.path.dirname(__file__)
+    pattern = pattern or "test_*.py"
+    # We are inside unittest.test, so the top-level is two notches up
+    top_level_dir = os.path.dirname(os.path.dirname(this_dir))
+    package_tests = loader.discover(start_dir=this_dir, pattern=pattern,
+                                    top_level_dir=top_level_dir)
+    standard_tests.addTests(package_tests)
+    return standard_tests
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/unittest/test/support.py b/Lib/unittest/test/support.py
index dbe4ddcd0e..02e8f3a00b 100644
--- a/Lib/unittest/test/support.py
+++ b/Lib/unittest/test/support.py
@@ -41,7 +41,7 @@ class TestHashing(object):
                 self.fail("Problem hashing %s and %s: %s" % (obj_1, obj_2, e))
 
 
-class LoggingResult(unittest.TestResult):
+class _BaseLoggingResult(unittest.TestResult):
     def __init__(self, log):
         self._events = log
         super().__init__()
@@ -52,7 +52,7 @@ class LoggingResult(unittest.TestResult):
 
     def startTestRun(self):
         self._events.append('startTestRun')
-        super(LoggingResult, self).startTestRun()
+        super().startTestRun()
 
     def stopTest(self, test):
         self._events.append('stopTest')
@@ -60,7 +60,7 @@ class LoggingResult(unittest.TestResult):
 
     def stopTestRun(self):
         self._events.append('stopTestRun')
-        super(LoggingResult, self).stopTestRun()
+        super().stopTestRun()
 
     def addFailure(self, *args):
         self._events.append('addFailure')
@@ -68,7 +68,7 @@ class LoggingResult(unittest.TestResult):
 
     def addSuccess(self, *args):
         self._events.append('addSuccess')
-        super(LoggingResult, self).addSuccess(*args)
+        super().addSuccess(*args)
 
     def addError(self, *args):
         self._events.append('addError')
@@ -76,15 +76,39 @@ class LoggingResult(unittest.TestResult):
 
     def addSkip(self, *args):
         self._events.append('addSkip')
-        super(LoggingResult, self).addSkip(*args)
+        super().addSkip(*args)
 
     def addExpectedFailure(self, *args):
         self._events.append('addExpectedFailure')
-        super(LoggingResult, self).addExpectedFailure(*args)
+        super().addExpectedFailure(*args)
 
     def addUnexpectedSuccess(self, *args):
         self._events.append('addUnexpectedSuccess')
-        super(LoggingResult, self).addUnexpectedSuccess(*args)
+        super().addUnexpectedSuccess(*args)
+
+
+class LegacyLoggingResult(_BaseLoggingResult):
+    """
+    A legacy TestResult implementation, without an addSubTest method,
+    which records its method calls.
+    """
+
+    @property
+    def addSubTest(self):
+        raise AttributeError
+
+
+class LoggingResult(_BaseLoggingResult):
+    """
+    A TestResult implementation which records its method calls.
+    """
+
+    def addSubTest(self, test, subtest, err):
+        if err is None:
+            self._events.append('addSubTestSuccess')
+        else:
+            self._events.append('addSubTestFailure')
+        super().addSubTest(test, subtest, err)
 
 
 class ResultWithNoStartTestRunStopTestRun(object):
diff --git a/Lib/unittest/test/test_assertions.py b/Lib/unittest/test/test_assertions.py
index 7931cadaf3..af08d5ad65 100644
--- a/Lib/unittest/test/test_assertions.py
+++ b/Lib/unittest/test/test_assertions.py
@@ -361,3 +361,7 @@ class TestLongMessage(unittest.TestCase):
                               ['^"regex" does not match "foo"$', '^oops$',
                                '^"regex" does not match "foo"$',
                                '^"regex" does not match "foo" : oops$'])
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_break.py b/Lib/unittest/test/test_break.py
index 75532f42d3..0bf1a229b8 100644
--- a/Lib/unittest/test/test_break.py
+++ b/Lib/unittest/test/test_break.py
@@ -282,3 +282,7 @@ class TestBreakSignalIgnored(TestBreak):
     "if threads have been used")
 class TestBreakSignalDefault(TestBreak):
     int_handler = signal.SIG_DFL
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py
index b8cb0c76b7..4b93179335 100644
--- a/Lib/unittest/test/test_case.py
+++ b/Lib/unittest/test/test_case.py
@@ -1,8 +1,10 @@
+import contextlib
 import difflib
 import pprint
 import pickle
 import re
 import sys
+import logging
 import warnings
 import weakref
 import inspect
@@ -13,9 +15,15 @@ from test import support
 import unittest
 
 from .support import (
-    TestEquality, TestHashing, LoggingResult,
+    TestEquality, TestHashing, LoggingResult, LegacyLoggingResult,
     ResultWithNoStartTestRunStopTestRun
 )
+from test.support import captured_stderr
+
+
+log_foo = logging.getLogger('foo')
+log_foobar = logging.getLogger('foo.bar')
+log_quux = logging.getLogger('quux')
 
 
 class Test(object):
@@ -297,6 +305,98 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing):
 
         Foo('test').run()
 
+    def _check_call_order__subtests(self, result, events, expected_events):
+        class Foo(Test.LoggingTestCase):
+            def test(self):
+                super(Foo, self).test()
+                for i in [1, 2, 3]:
+                    with self.subTest(i=i):
+                        if i == 1:
+                            self.fail('failure')
+                        for j in [2, 3]:
+                            with self.subTest(j=j):
+                                if i * j == 6:
+                                    raise RuntimeError('raised by Foo.test')
+                1 / 0
+
+        # Order is the following:
+        # i=1 => subtest failure
+        # i=2, j=2 => subtest success
+        # i=2, j=3 => subtest error
+        # i=3, j=2 => subtest error
+        # i=3, j=3 => subtest success
+        # toplevel => error
+        Foo(events).run(result)
+        self.assertEqual(events, expected_events)
+
+    def test_run_call_order__subtests(self):
+        events = []
+        result = LoggingResult(events)
+        expected = ['startTest', 'setUp', 'test', 'tearDown',
+                    'addSubTestFailure', 'addSubTestSuccess',
+                    'addSubTestFailure', 'addSubTestFailure',
+                    'addSubTestSuccess', 'addError', 'stopTest']
+        self._check_call_order__subtests(result, events, expected)
+
+    def test_run_call_order__subtests_legacy(self):
+        # With a legacy result object (without a addSubTest method),
+        # text execution stops after the first subtest failure.
+        events = []
+        result = LegacyLoggingResult(events)
+        expected = ['startTest', 'setUp', 'test', 'tearDown',
+                    'addFailure', 'stopTest']
+        self._check_call_order__subtests(result, events, expected)
+
+    def _check_call_order__subtests_success(self, result, events, expected_events):
+        class Foo(Test.LoggingTestCase):
+            def test(self):
+                super(Foo, self).test()
+                for i in [1, 2]:
+                    with self.subTest(i=i):
+                        for j in [2, 3]:
+                            with self.subTest(j=j):
+                                pass
+
+        Foo(events).run(result)
+        self.assertEqual(events, expected_events)
+
+    def test_run_call_order__subtests_success(self):
+        events = []
+        result = LoggingResult(events)
+        # The 6 subtest successes are individually recorded, in addition
+        # to the whole test success.
+        expected = (['startTest', 'setUp', 'test', 'tearDown']
+                    + 6 * ['addSubTestSuccess']
+                    + ['addSuccess', 'stopTest'])
+        self._check_call_order__subtests_success(result, events, expected)
+
+    def test_run_call_order__subtests_success_legacy(self):
+        # With a legacy result, only the whole test success is recorded.
+        events = []
+        result = LegacyLoggingResult(events)
+        expected = ['startTest', 'setUp', 'test', 'tearDown',
+                    'addSuccess', 'stopTest']
+        self._check_call_order__subtests_success(result, events, expected)
+
+    def test_run_call_order__subtests_failfast(self):
+        events = []
+        result = LoggingResult(events)
+        result.failfast = True
+
+        class Foo(Test.LoggingTestCase):
+            def test(self):
+                super(Foo, self).test()
+                with self.subTest(i=1):
+                    self.fail('failure')
+                with self.subTest(i=2):
+                    self.fail('failure')
+                self.fail('failure')
+
+        expected = ['startTest', 'setUp', 'test', 'tearDown',
+                    'addSubTestFailure', 'stopTest']
+        Foo(events).run(result)
+        self.assertEqual(events, expected)
+
     # "This class attribute gives the exception raised by the test() method.
     # If a test framework needs to use a specialized exception, possibly to
     # carry additional information, it must subclass this exception in
@@ -729,18 +829,18 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing):
 
         # set a lower threshold value and add a cleanup to restore it
         old_threshold = self._diffThreshold
-        self._diffThreshold = 2**8
+        self._diffThreshold = 2**5
         self.addCleanup(lambda: setattr(self, '_diffThreshold', old_threshold))
 
         # under the threshold: diff marker (^) in error message
-        s = 'x' * (2**7)
+        s = 'x' * (2**4)
         with self.assertRaises(self.failureException) as cm:
             self.assertEqual(s + 'a', s + 'b')
         self.assertIn('^', str(cm.exception))
         self.assertEqual(s + 'a', s + 'a')
 
         # over the threshold: diff not used and marker (^) not in error message
-        s = 'x' * (2**9)
+        s = 'x' * (2**6)
         # if the path that uses difflib is taken, _truncateMessage will be
         # called -- replace it with explodingTruncation to verify that this
         # doesn't happen
@@ -757,6 +857,37 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing):
         self.assertEqual(str(cm.exception), '%r != %r' % (s1, s2))
         self.assertEqual(s + 'a', s + 'a')
 
+    def testAssertEqual_shorten(self):
+        # set a lower threshold value and add a cleanup to restore it
+        old_threshold = self._diffThreshold
+        self._diffThreshold = 0
+        self.addCleanup(lambda: setattr(self, '_diffThreshold', old_threshold))
+
+        s = 'x' * 100
+        s1, s2 = s + 'a', s + 'b'
+        with self.assertRaises(self.failureException) as cm:
+            self.assertEqual(s1, s2)
+        c = 'xxxx[35 chars]' + 'x' * 61
+        self.assertEqual(str(cm.exception), "'%sa' != '%sb'" % (c, c))
+        self.assertEqual(s + 'a', s + 'a')
+
+        p = 'y' * 50
+        s1, s2 = s + 'a' + p, s + 'b' + p
+        with self.assertRaises(self.failureException) as cm:
+            self.assertEqual(s1, s2)
+        c = 'xxxx[85 chars]xxxxxxxxxxx'
+        #print()
+        #print(str(cm.exception))
+        self.assertEqual(str(cm.exception), "'%sa%s' != '%sb%s'" % (c, p, c, p))
+
+        p = 'y' * 100
+        s1, s2 = s + 'a' + p, s + 'b' + p
+        with self.assertRaises(self.failureException) as cm:
+            self.assertEqual(s1, s2)
+        c = 'xxxx[91 chars]xxxxx'
+        d = 'y' * 40 + '[56 chars]yyyy'
+        self.assertEqual(str(cm.exception), "'%sa%s' != '%sb%s'" % (c, d, c, d))
+
     def testAssertCountEqual(self):
         a = object()
         self.assertCountEqual([1, 2, 3], [3, 2, 1])
@@ -1159,6 +1290,94 @@ test case
                 with self.assertWarnsRegex(RuntimeWarning, "o+"):
                     _runtime_warn("barz")
 
+    @contextlib.contextmanager
+    def assertNoStderr(self):
+        with captured_stderr() as buf:
+            yield
+        self.assertEqual(buf.getvalue(), "")
+
+    def assertLogRecords(self, records, matches):
+        self.assertEqual(len(records), len(matches))
+        for rec, match in zip(records, matches):
+            self.assertIsInstance(rec, logging.LogRecord)
+            for k, v in match.items():
+                self.assertEqual(getattr(rec, k), v)
+
+    def testAssertLogsDefaults(self):
+        # defaults: root logger, level INFO
+        with self.assertNoStderr():
+            with self.assertLogs() as cm:
+                log_foo.info("1")
+                log_foobar.debug("2")
+            self.assertEqual(cm.output, ["INFO:foo:1"])
+            self.assertLogRecords(cm.records, [{'name': 'foo'}])
+
+    def testAssertLogsTwoMatchingMessages(self):
+        # Same, but with two matching log messages
+        with self.assertNoStderr():
+            with self.assertLogs() as cm:
+                log_foo.info("1")
+                log_foobar.debug("2")
+                log_quux.warning("3")
+            self.assertEqual(cm.output, ["INFO:foo:1", "WARNING:quux:3"])
+            self.assertLogRecords(cm.records,
+                                   [{'name': 'foo'}, {'name': 'quux'}])
+
+    def checkAssertLogsPerLevel(self, level):
+        # Check level filtering
+        with self.assertNoStderr():
+            with self.assertLogs(level=level) as cm:
+                log_foo.warning("1")
+                log_foobar.error("2")
+                log_quux.critical("3")
+            self.assertEqual(cm.output, ["ERROR:foo.bar:2", "CRITICAL:quux:3"])
+            self.assertLogRecords(cm.records,
+                                   [{'name': 'foo.bar'}, {'name': 'quux'}])
+
+    def testAssertLogsPerLevel(self):
+        self.checkAssertLogsPerLevel(logging.ERROR)
+        self.checkAssertLogsPerLevel('ERROR')
+
+    def checkAssertLogsPerLogger(self, logger):
+        # Check per-logger fitering
+        with self.assertNoStderr():
+            with self.assertLogs(level='DEBUG') as outer_cm:
+                with self.assertLogs(logger, level='DEBUG') as cm:
+                    log_foo.info("1")
+                    log_foobar.debug("2")
+                    log_quux.warning("3")
+                self.assertEqual(cm.output, ["INFO:foo:1", "DEBUG:foo.bar:2"])
+                self.assertLogRecords(cm.records,
+                                       [{'name': 'foo'}, {'name': 'foo.bar'}])
+            # The outer catchall caught the quux log
+            self.assertEqual(outer_cm.output, ["WARNING:quux:3"])
+
+    def testAssertLogsPerLogger(self):
+        self.checkAssertLogsPerLogger(logging.getLogger('foo'))
+        self.checkAssertLogsPerLogger('foo')
+
+    def testAssertLogsFailureNoLogs(self):
+        # Failure due to no logs
+        with self.assertNoStderr():
+            with self.assertRaises(self.failureException):
+                with self.assertLogs():
+                    pass
+
+    def testAssertLogsFailureLevelTooHigh(self):
+        # Failure due to level too high
+        with self.assertNoStderr():
+            with self.assertRaises(self.failureException):
+                with self.assertLogs(level='WARNING'):
+                    log_foo.info("1")
+
+    def testAssertLogsFailureMismatchingLogger(self):
+        # Failure due to mismatching logger (and the logged message is
+        # passed through)
+        with self.assertLogs('quux', level='ERROR'):
+            with self.assertRaises(self.failureException):
+                with self.assertLogs('foo'):
+                    log_quux.error("1")
+
     def testDeprecatedMethodNames(self):
         """
         Test that the deprecated methods raise a DeprecationWarning. See #9424.
@@ -1313,3 +1532,7 @@ test case
         with support.disable_gc():
             del case
             self.assertFalse(wr())
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_discovery.py b/Lib/unittest/test/test_discovery.py
index ccc7db249e..6b7b1280f8 100644
--- a/Lib/unittest/test/test_discovery.py
+++ b/Lib/unittest/test/test_discovery.py
@@ -1,12 +1,15 @@
 import os
 import re
 import sys
+import types
+import builtins
+from test import support
 
 import unittest
 
 
 class TestableTestProgram(unittest.TestProgram):
-    module = '__main__'
+    module = None
     exit = True
     defaultTest = failfast = catchbreak = buffer = None
     verbosity = 1
@@ -46,9 +49,9 @@ class TestDiscovery(unittest.TestCase):
         def restore_isdir():
             os.path.isdir = original_isdir
 
-        path_lists = [['test1.py', 'test2.py', 'not_a_test.py', 'test_dir',
+        path_lists = [['test2.py', 'test1.py', 'not_a_test.py', 'test_dir',
                        'test.foo', 'test-not-a-module.py', 'another_dir'],
-                      ['test3.py', 'test4.py', ]]
+                      ['test4.py', 'test3.py', ]]
         os.listdir = lambda path: path_lists.pop(0)
         self.addCleanup(restore_listdir)
 
@@ -70,6 +73,8 @@ class TestDiscovery(unittest.TestCase):
         loader._top_level_dir = top_level
         suite = list(loader._find_tests(top_level, 'test*.py'))
 
+        # The test suites found should be sorted alphabetically for reliable
+        # execution order.
         expected = [name + ' module tests' for name in
                     ('test1', 'test2')]
         expected.extend([('test_dir.%s' % name) + ' module tests' for name in
@@ -132,6 +137,7 @@ class TestDiscovery(unittest.TestCase):
         # and directly from the test_directory2 package
         self.assertEqual(suite,
                          ['load_tests', 'test_directory2' + ' module tests'])
+        # The test module paths should be sorted for reliable execution order
         self.assertEqual(Module.paths, ['test_directory', 'test_directory2'])
 
         # load_tests should have been called once with loader, tests and pattern
@@ -169,7 +175,7 @@ class TestDiscovery(unittest.TestCase):
         self.addCleanup(restore_isdir)
 
         _find_tests_args = []
-        def _find_tests(start_dir, pattern):
+        def _find_tests(start_dir, pattern, namespace=None):
             _find_tests_args.append((start_dir, pattern))
             return ['tests']
         loader._find_tests = _find_tests
@@ -184,11 +190,9 @@ class TestDiscovery(unittest.TestCase):
         self.assertEqual(_find_tests_args, [(start_dir, 'pattern')])
         self.assertIn(top_level_dir, sys.path)
 
-    def test_discover_with_modules_that_fail_to_import(self):
-        loader = unittest.TestLoader()
-
+    def setup_import_issue_tests(self, fakefile):
         listdir = os.listdir
-        os.listdir = lambda _: ['test_this_does_not_exist.py']
+        os.listdir = lambda _: [fakefile]
         isfile = os.path.isfile
         os.path.isfile = lambda _: True
         orig_sys_path = sys.path[:]
@@ -198,6 +202,11 @@ class TestDiscovery(unittest.TestCase):
             sys.path[:] = orig_sys_path
         self.addCleanup(restore)
 
+    def test_discover_with_modules_that_fail_to_import(self):
+        loader = unittest.TestLoader()
+
+        self.setup_import_issue_tests('test_this_does_not_exist.py')
+
         suite = loader.discover('.')
         self.assertIn(os.getcwd(), sys.path)
         self.assertEqual(suite.countTestCases(), 1)
@@ -206,62 +215,74 @@ class TestDiscovery(unittest.TestCase):
         with self.assertRaises(ImportError):
             test.test_this_does_not_exist()
 
+    def test_discover_with_module_that_raises_SkipTest_on_import(self):
+        loader = unittest.TestLoader()
+
+        def _get_module_from_name(name):
+            raise unittest.SkipTest('skipperoo')
+        loader._get_module_from_name = _get_module_from_name
+
+        self.setup_import_issue_tests('test_skip_dummy.py')
+
+        suite = loader.discover('.')
+        self.assertEqual(suite.countTestCases(), 1)
+
+        result = unittest.TestResult()
+        suite.run(result)
+        self.assertEqual(len(result.skipped), 1)
+
     def test_command_line_handling_parseArgs(self):
         program = TestableTestProgram()
 
         args = []
-        def do_discovery(argv):
-            args.extend(argv)
-        program._do_discovery = do_discovery
+        program._do_discovery = args.append
         program.parseArgs(['something', 'discover'])
-        self.assertEqual(args, [])
+        self.assertEqual(args, [[]])
 
+        args[:] = []
         program.parseArgs(['something', 'discover', 'foo', 'bar'])
-        self.assertEqual(args, ['foo', 'bar'])
+        self.assertEqual(args, [['foo', 'bar']])
 
     def test_command_line_handling_discover_by_default(self):
         program = TestableTestProgram()
-        program.module = None
 
-        self.called = False
-        def do_discovery(argv):
-            self.called = True
-            self.assertEqual(argv, [])
-        program._do_discovery = do_discovery
+        args = []
+        program._do_discovery = args.append
         program.parseArgs(['something'])
-        self.assertTrue(self.called)
+        self.assertEqual(args, [[]])
+        self.assertEqual(program.verbosity, 1)
+        self.assertIs(program.buffer, False)
+        self.assertIs(program.catchbreak, False)
+        self.assertIs(program.failfast, False)
 
     def test_command_line_handling_discover_by_default_with_options(self):
         program = TestableTestProgram()
-        program.module = None
 
-        args = ['something', '-v', '-b', '-v', '-c', '-f']
-        self.called = False
-        def do_discovery(argv):
-            self.called = True
-            self.assertEqual(argv, args[1:])
-        program._do_discovery = do_discovery
-        program.parseArgs(args)
-        self.assertTrue(self.called)
+        args = []
+        program._do_discovery = args.append
+        program.parseArgs(['something', '-v', '-b', '-v', '-c', '-f'])
+        self.assertEqual(args, [[]])
+        self.assertEqual(program.verbosity, 2)
+        self.assertIs(program.buffer, True)
+        self.assertIs(program.catchbreak, True)
+        self.assertIs(program.failfast, True)
 
 
     def test_command_line_handling_do_discovery_too_many_arguments(self):
-        class Stop(Exception):
-            pass
-        def usageExit():
-            raise Stop
-
         program = TestableTestProgram()
-        program.usageExit = usageExit
         program.testLoader = None
 
-        with self.assertRaises(Stop):
+        with support.captured_stderr() as stderr, \
+             self.assertRaises(SystemExit) as cm:
             # too many args
             program._do_discovery(['one', 'two', 'three', 'four'])
+        self.assertEqual(cm.exception.args, (2,))
+        self.assertIn('usage:', stderr.getvalue())
 
 
     def test_command_line_handling_do_discovery_uses_default_loader(self):
         program = object.__new__(unittest.TestProgram)
+        program._initArgParsers()
 
         class Loader(object):
             args = []
@@ -417,7 +438,7 @@ class TestDiscovery(unittest.TestCase):
         expectedPath = os.path.abspath(os.path.dirname(unittest.test.__file__))
 
         self.wasRun = False
-        def _find_tests(start_dir, pattern):
+        def _find_tests(start_dir, pattern, namespace=None):
             self.wasRun = True
             self.assertEqual(start_dir, expectedPath)
             return tests
@@ -427,5 +448,79 @@ class TestDiscovery(unittest.TestCase):
         self.assertEqual(suite._tests, tests)
 
 
+    def test_discovery_from_dotted_path_builtin_modules(self):
+
+        loader = unittest.TestLoader()
+
+        listdir = os.listdir
+        os.listdir = lambda _: ['test_this_does_not_exist.py']
+        isfile = os.path.isfile
+        isdir = os.path.isdir
+        os.path.isdir = lambda _: False
+        orig_sys_path = sys.path[:]
+        def restore():
+            os.path.isfile = isfile
+            os.path.isdir = isdir
+            os.listdir = listdir
+            sys.path[:] = orig_sys_path
+        self.addCleanup(restore)
+
+        with self.assertRaises(TypeError) as cm:
+            loader.discover('sys')
+        self.assertEqual(str(cm.exception),
+                         'Can not use builtin modules '
+                         'as dotted module names')
+
+    def test_discovery_from_dotted_namespace_packages(self):
+        loader = unittest.TestLoader()
+
+        orig_import = __import__
+        package = types.ModuleType('package')
+        package.__path__ = ['/a', '/b']
+        package.__spec__ = types.SimpleNamespace(
+           loader=None,
+           submodule_search_locations=['/a', '/b']
+        )
+
+        def _import(packagename, *args, **kwargs):
+            sys.modules[packagename] = package
+            return package
+
+        def cleanup():
+            builtins.__import__ = orig_import
+        self.addCleanup(cleanup)
+        builtins.__import__ = _import
+
+        _find_tests_args = []
+        def _find_tests(start_dir, pattern, namespace=None):
+            _find_tests_args.append((start_dir, pattern))
+            return ['%s/tests' % start_dir]
+
+        loader._find_tests = _find_tests
+        loader.suiteClass = list
+        suite = loader.discover('package')
+        self.assertEqual(suite, ['/a/tests', '/b/tests'])
+
+    def test_discovery_failed_discovery(self):
+        loader = unittest.TestLoader()
+        package = types.ModuleType('package')
+        orig_import = __import__
+
+        def _import(packagename, *args, **kwargs):
+            sys.modules[packagename] = package
+            return package
+
+        def cleanup():
+            builtins.__import__ = orig_import
+        self.addCleanup(cleanup)
+        builtins.__import__ = _import
+
+        with self.assertRaises(TypeError) as cm:
+            loader.discover('package')
+        self.assertEqual(str(cm.exception),
+                         'don\'t know how to discover from {!r}'
+                         .format(package))
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/test/test_functiontestcase.py b/Lib/unittest/test/test_functiontestcase.py
index 9ce5ee3556..d7fe07a53b 100644
--- a/Lib/unittest/test/test_functiontestcase.py
+++ b/Lib/unittest/test/test_functiontestcase.py
@@ -142,3 +142,7 @@ class Test_FunctionTestCase(unittest.TestCase):
         test = unittest.FunctionTestCase(lambda: None, description=desc)
 
         self.assertEqual(test.shortDescription(), "this tests foo")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_loader.py b/Lib/unittest/test/test_loader.py
index fcd2e07624..b62a1b5c54 100644
--- a/Lib/unittest/test/test_loader.py
+++ b/Lib/unittest/test/test_loader.py
@@ -1306,3 +1306,7 @@ class Test_TestLoader(unittest.TestCase):
     def test_suiteClass__default_value(self):
         loader = unittest.TestLoader()
         self.assertIs(loader.suiteClass, unittest.TestSuite)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_program.py b/Lib/unittest/test/test_program.py
index 8a4b3fad58..3294298030 100644
--- a/Lib/unittest/test/test_program.py
+++ b/Lib/unittest/test/test_program.py
@@ -2,6 +2,7 @@ import io
 
 import os
 import sys
+from test import support
 import unittest
 
 
@@ -64,6 +65,41 @@ class Test_TestProgram(unittest.TestCase):
             return self.suiteClass(
                 [self.loadTestsFromTestCase(Test_TestProgram.FooBar)])
 
+        def loadTestsFromNames(self, names, module):
+            return self.suiteClass(
+                [self.loadTestsFromTestCase(Test_TestProgram.FooBar)])
+
+    def test_defaultTest_with_string(self):
+        class FakeRunner(object):
+            def run(self, test):
+                self.test = test
+                return True
+
+        old_argv = sys.argv
+        sys.argv = ['faketest']
+        runner = FakeRunner()
+        program = unittest.TestProgram(testRunner=runner, exit=False,
+                                       defaultTest='unittest.test',
+                                       testLoader=self.FooBarLoader())
+        sys.argv = old_argv
+        self.assertEqual(('unittest.test',), program.testNames)
+
+    def test_defaultTest_with_iterable(self):
+        class FakeRunner(object):
+            def run(self, test):
+                self.test = test
+                return True
+
+        old_argv = sys.argv
+        sys.argv = ['faketest']
+        runner = FakeRunner()
+        program = unittest.TestProgram(
+            testRunner=runner, exit=False,
+            defaultTest=['unittest.test', 'unittest.test2'],
+            testLoader=self.FooBarLoader())
+        sys.argv = old_argv
+        self.assertEqual(['unittest.test', 'unittest.test2'],
+                          program.testNames)
 
     def test_NonExit(self):
         program = unittest.main(exit=False,
@@ -151,20 +187,38 @@ class TestCommandLineArgs(unittest.TestCase):
             if attr == 'catch' and not hasInstallHandler:
                 continue
 
+            setattr(program, attr, None)
+            program.parseArgs([None])
+            self.assertIs(getattr(program, attr), False)
+
+            false = []
+            setattr(program, attr, false)
+            program.parseArgs([None])
+            self.assertIs(getattr(program, attr), false)
+
+            true = [42]
+            setattr(program, attr, true)
+            program.parseArgs([None])
+            self.assertIs(getattr(program, attr), true)
+
             short_opt = '-%s' % arg[0]
             long_opt = '--%s' % arg
             for opt in short_opt, long_opt:
                 setattr(program, attr, None)
-
-                program.parseArgs([None, opt])
-                self.assertTrue(getattr(program, attr))
-
-            for opt in short_opt, long_opt:
-                not_none = object()
-                setattr(program, attr, not_none)
-
                 program.parseArgs([None, opt])
-                self.assertEqual(getattr(program, attr), not_none)
+                self.assertIs(getattr(program, attr), True)
+
+                setattr(program, attr, False)
+                with support.captured_stderr() as stderr, \
+                    self.assertRaises(SystemExit) as cm:
+                    program.parseArgs([None, opt])
+                self.assertEqual(cm.exception.args, (2,))
+
+                setattr(program, attr, True)
+                with support.captured_stderr() as stderr, \
+                    self.assertRaises(SystemExit) as cm:
+                    program.parseArgs([None, opt])
+                self.assertEqual(cm.exception.args, (2,))
 
     def testWarning(self):
         """Test the warnings argument"""
diff --git a/Lib/unittest/test/test_result.py b/Lib/unittest/test/test_result.py
index 7d40725cf2..489fe17754 100644
--- a/Lib/unittest/test/test_result.py
+++ b/Lib/unittest/test/test_result.py
@@ -227,6 +227,40 @@ class Test_TestResult(unittest.TestCase):
         self.assertIs(test_case, test)
         self.assertIsInstance(formatted_exc, str)
 
+    def test_addSubTest(self):
+        class Foo(unittest.TestCase):
+            def test_1(self):
+                nonlocal subtest
+                with self.subTest(foo=1):
+                    subtest = self._subtest
+                    try:
+                        1/0
+                    except ZeroDivisionError:
+                        exc_info_tuple = sys.exc_info()
+                    # Register an error by hand (to check the API)
+                    result.addSubTest(test, subtest, exc_info_tuple)
+                    # Now trigger a failure
+                    self.fail("some recognizable failure")
+
+        subtest = None
+        test = Foo('test_1')
+        result = unittest.TestResult()
+
+        test.run(result)
+
+        self.assertFalse(result.wasSuccessful())
+        self.assertEqual(len(result.errors), 1)
+        self.assertEqual(len(result.failures), 1)
+        self.assertEqual(result.testsRun, 1)
+        self.assertEqual(result.shouldStop, False)
+
+        test_case, formatted_exc = result.errors[0]
+        self.assertIs(test_case, subtest)
+        self.assertIn("ZeroDivisionError", formatted_exc)
+        test_case, formatted_exc = result.failures[0]
+        self.assertIs(test_case, subtest)
+        self.assertIn("some recognizable failure", formatted_exc)
+
     def testGetDescriptionWithoutDocstring(self):
         result = unittest.TextTestResult(None, True, 1)
         self.assertEqual(
@@ -234,6 +268,37 @@ class Test_TestResult(unittest.TestCase):
                 'testGetDescriptionWithoutDocstring (' + __name__ +
                 '.Test_TestResult)')
 
+    def testGetSubTestDescriptionWithoutDocstring(self):
+        with self.subTest(foo=1, bar=2):
+            result = unittest.TextTestResult(None, True, 1)
+            self.assertEqual(
+                    result.getDescription(self._subtest),
+                    'testGetSubTestDescriptionWithoutDocstring (' + __name__ +
+                    '.Test_TestResult) (bar=2, foo=1)')
+        with self.subTest('some message'):
+            result = unittest.TextTestResult(None, True, 1)
+            self.assertEqual(
+                    result.getDescription(self._subtest),
+                    'testGetSubTestDescriptionWithoutDocstring (' + __name__ +
+                    '.Test_TestResult) [some message]')
+
+    def testGetSubTestDescriptionWithoutDocstringAndParams(self):
+        with self.subTest():
+            result = unittest.TextTestResult(None, True, 1)
+            self.assertEqual(
+                    result.getDescription(self._subtest),
+                    'testGetSubTestDescriptionWithoutDocstringAndParams '
+                    '(' + __name__ + '.Test_TestResult) (<subtest>)')
+
+    def testGetNestedSubTestDescriptionWithoutDocstring(self):
+        with self.subTest(foo=1):
+            with self.subTest(bar=2):
+                result = unittest.TextTestResult(None, True, 1)
+                self.assertEqual(
+                        result.getDescription(self._subtest),
+                        'testGetNestedSubTestDescriptionWithoutDocstring '
+                        '(' + __name__ + '.Test_TestResult) (bar=2, foo=1)')
+
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
     def testGetDescriptionWithOneLineDocstring(self):
@@ -247,6 +312,18 @@ class Test_TestResult(unittest.TestCase):
 
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
+    def testGetSubTestDescriptionWithOneLineDocstring(self):
+        """Tests getDescription() for a method with a docstring."""
+        result = unittest.TextTestResult(None, True, 1)
+        with self.subTest(foo=1, bar=2):
+            self.assertEqual(
+                result.getDescription(self._subtest),
+               ('testGetSubTestDescriptionWithOneLineDocstring '
+                '(' + __name__ + '.Test_TestResult) (bar=2, foo=1)\n'
+                'Tests getDescription() for a method with a docstring.'))
+
+    @unittest.skipIf(sys.flags.optimize >= 2,
+                     "Docstrings are omitted with -O2 and above")
     def testGetDescriptionWithMultiLineDocstring(self):
         """Tests getDescription() for a method with a longer docstring.
         The second line of the docstring.
@@ -259,6 +336,21 @@ class Test_TestResult(unittest.TestCase):
                 'Tests getDescription() for a method with a longer '
                 'docstring.'))
 
+    @unittest.skipIf(sys.flags.optimize >= 2,
+                     "Docstrings are omitted with -O2 and above")
+    def testGetSubTestDescriptionWithMultiLineDocstring(self):
+        """Tests getDescription() for a method with a longer docstring.
+        The second line of the docstring.
+        """
+        result = unittest.TextTestResult(None, True, 1)
+        with self.subTest(foo=1, bar=2):
+            self.assertEqual(
+                result.getDescription(self._subtest),
+               ('testGetSubTestDescriptionWithMultiLineDocstring '
+                '(' + __name__ + '.Test_TestResult) (bar=2, foo=1)\n'
+                'Tests getDescription() for a method with a longer '
+                'docstring.'))
+
     def testStackFrameTrimming(self):
         class Frame(object):
             class tb_frame(object):
diff --git a/Lib/unittest/test/test_runner.py b/Lib/unittest/test/test_runner.py
index e22e6bc279..ef1c1af9f1 100644
--- a/Lib/unittest/test/test_runner.py
+++ b/Lib/unittest/test/test_runner.py
@@ -5,6 +5,7 @@ import pickle
 import subprocess
 
 import unittest
+from unittest.case import _Outcome
 
 from .support import LoggingResult, ResultWithNoStartTestRunStopTestRun
 
@@ -42,12 +43,8 @@ class TestCleanUp(unittest.TestCase):
             def testNothing(self):
                 pass
 
-        class MockOutcome(object):
-            success = True
-            errors = []
-
         test = TestableTest('testNothing')
-        test._outcomeForDoCleanups = MockOutcome
+        outcome = test._outcome = _Outcome()
 
         exc1 = Exception('foo')
         exc2 = Exception('bar')
@@ -61,9 +58,10 @@ class TestCleanUp(unittest.TestCase):
         test.addCleanup(cleanup2)
 
         self.assertFalse(test.doCleanups())
-        self.assertFalse(MockOutcome.success)
+        self.assertFalse(outcome.success)
 
-        (Type1, instance1, _), (Type2, instance2, _) = reversed(MockOutcome.errors)
+        ((_, (Type1, instance1, _)),
+         (_, (Type2, instance2, _))) = reversed(outcome.errors)
         self.assertEqual((Type1, instance1), (Exception, exc1))
         self.assertEqual((Type2, instance2), (Exception, exc2))
 
@@ -341,3 +339,7 @@ class Test_TextTestRunner(unittest.TestCase):
         f = io.StringIO()
         runner = unittest.TextTestRunner(f)
         self.assertTrue(runner.stream.stream is f)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_setups.py b/Lib/unittest/test/test_setups.py
index b8d5aa41e9..392f95efc0 100644
--- a/Lib/unittest/test/test_setups.py
+++ b/Lib/unittest/test/test_setups.py
@@ -494,14 +494,13 @@ class TestSetups(unittest.TestCase):
         Test.__module__ = 'Module'
         sys.modules['Module'] = Module
 
-        _suite = unittest.defaultTestLoader.loadTestsFromTestCase(Test)
-        suite = unittest.TestSuite()
-        suite.addTest(_suite)
-
         messages = ('setUpModule', 'tearDownModule', 'setUpClass', 'tearDownClass', 'test_something')
         for phase, msg in enumerate(messages):
+            _suite = unittest.defaultTestLoader.loadTestsFromTestCase(Test)
+            suite = unittest.TestSuite([_suite])
             with self.assertRaisesRegex(Exception, msg):
                 suite.debug()
 
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/test/test_skipping.py b/Lib/unittest/test/test_skipping.py
index 952240eeed..e18caa48ba 100644
--- a/Lib/unittest/test/test_skipping.py
+++ b/Lib/unittest/test/test_skipping.py
@@ -29,6 +29,31 @@ class Test_TestSkipping(unittest.TestCase):
         self.assertEqual(result.skipped, [(test, "testing")])
         self.assertEqual(result.testsRun, 1)
 
+    def test_skipping_subtests(self):
+        class Foo(unittest.TestCase):
+            def test_skip_me(self):
+                with self.subTest(a=1):
+                    with self.subTest(b=2):
+                        self.skipTest("skip 1")
+                    self.skipTest("skip 2")
+                self.skipTest("skip 3")
+        events = []
+        result = LoggingResult(events)
+        test = Foo("test_skip_me")
+        test.run(result)
+        self.assertEqual(events, ['startTest', 'addSkip', 'addSkip',
+                                  'addSkip', 'stopTest'])
+        self.assertEqual(len(result.skipped), 3)
+        subtest, msg = result.skipped[0]
+        self.assertEqual(msg, "skip 1")
+        self.assertIsInstance(subtest, unittest.TestCase)
+        self.assertIsNot(subtest, test)
+        subtest, msg = result.skipped[1]
+        self.assertEqual(msg, "skip 2")
+        self.assertIsInstance(subtest, unittest.TestCase)
+        self.assertIsNot(subtest, test)
+        self.assertEqual(result.skipped[2], (test, "skip 3"))
+
     def test_skipping_decorators(self):
         op_table = ((unittest.skipUnless, False, True),
                     (unittest.skipIf, True, False))
@@ -95,6 +120,31 @@ class Test_TestSkipping(unittest.TestCase):
         self.assertEqual(result.expectedFailures[0][0], test)
         self.assertTrue(result.wasSuccessful())
 
+    def test_expected_failure_subtests(self):
+        # A failure in any subtest counts as the expected failure of the
+        # whole test.
+        class Foo(unittest.TestCase):
+            @unittest.expectedFailure
+            def test_die(self):
+                with self.subTest():
+                    # This one succeeds
+                    pass
+                with self.subTest():
+                    self.fail("help me!")
+                with self.subTest():
+                    # This one doesn't get executed
+                    self.fail("shouldn't come here")
+        events = []
+        result = LoggingResult(events)
+        test = Foo("test_die")
+        test.run(result)
+        self.assertEqual(events,
+                         ['startTest', 'addSubTestSuccess',
+                          'addExpectedFailure', 'stopTest'])
+        self.assertEqual(len(result.expectedFailures), 1)
+        self.assertIs(result.expectedFailures[0][0], test)
+        self.assertTrue(result.wasSuccessful())
+
     def test_unexpected_success(self):
         class Foo(unittest.TestCase):
             @unittest.expectedFailure
@@ -110,6 +160,30 @@ class Test_TestSkipping(unittest.TestCase):
         self.assertEqual(result.unexpectedSuccesses, [test])
         self.assertTrue(result.wasSuccessful())
 
+    def test_unexpected_success_subtests(self):
+        # Success in all subtests counts as the unexpected success of
+        # the whole test.
+        class Foo(unittest.TestCase):
+            @unittest.expectedFailure
+            def test_die(self):
+                with self.subTest():
+                    # This one succeeds
+                    pass
+                with self.subTest():
+                    # So does this one
+                    pass
+        events = []
+        result = LoggingResult(events)
+        test = Foo("test_die")
+        test.run(result)
+        self.assertEqual(events,
+                         ['startTest',
+                          'addSubTestSuccess', 'addSubTestSuccess',
+                          'addUnexpectedSuccess', 'stopTest'])
+        self.assertFalse(result.failures)
+        self.assertEqual(result.unexpectedSuccesses, [test])
+        self.assertTrue(result.wasSuccessful())
+
     def test_skip_doesnt_run_setup(self):
         class Foo(unittest.TestCase):
             wasSetUp = False
@@ -147,3 +221,7 @@ class Test_TestSkipping(unittest.TestCase):
         suite = unittest.TestSuite([test])
         suite.run(result)
         self.assertEqual(result.skipped, [(test, "testing")])
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/test_suite.py b/Lib/unittest/test/test_suite.py
index 2db978ddb8..54cec6ecba 100644
--- a/Lib/unittest/test/test_suite.py
+++ b/Lib/unittest/test/test_suite.py
@@ -1,6 +1,8 @@
 import unittest
 
+import gc
 import sys
+import weakref
 from .support import LoggingResult, TestEquality
 
 
@@ -300,7 +302,54 @@ class Test_TestSuite(unittest.TestCase, TestEquality):
         # when the bug is fixed this line will not crash
         suite.run(unittest.TestResult())
 
+    def test_remove_test_at_index(self):
+        if not unittest.BaseTestSuite._cleanup:
+            raise unittest.SkipTest("Suite cleanup is disabled")
 
+        suite = unittest.TestSuite()
+
+        suite._tests = [1, 2, 3]
+        suite._removeTestAtIndex(1)
+
+        self.assertEqual([1, None, 3], suite._tests)
+
+    def test_remove_test_at_index_not_indexable(self):
+        if not unittest.BaseTestSuite._cleanup:
+            raise unittest.SkipTest("Suite cleanup is disabled")
+
+        suite = unittest.TestSuite()
+        suite._tests = None
+
+        # if _removeAtIndex raises for noniterables this next line will break
+        suite._removeTestAtIndex(2)
+
+    def assert_garbage_collect_test_after_run(self, TestSuiteClass):
+        if not unittest.BaseTestSuite._cleanup:
+            raise unittest.SkipTest("Suite cleanup is disabled")
+
+        class Foo(unittest.TestCase):
+            def test_nothing(self):
+                pass
+
+        test = Foo('test_nothing')
+        wref = weakref.ref(test)
+
+        suite = TestSuiteClass([wref()])
+        suite.run(unittest.TestResult())
+
+        del test
+
+        # for the benefit of non-reference counting implementations
+        gc.collect()
+
+        self.assertEqual(suite._tests, [None])
+        self.assertIsNone(wref())
+
+    def test_garbage_collect_test_after_run_BaseTestSuite(self):
+        self.assert_garbage_collect_test_after_run(unittest.BaseTestSuite)
+
+    def test_garbage_collect_test_after_run_TestSuite(self):
+        self.assert_garbage_collect_test_after_run(unittest.TestSuite)
 
     def test_basetestsuite(self):
         class Test(unittest.TestCase):
@@ -363,6 +412,5 @@ class Test_TestSuite(unittest.TestCase, TestEquality):
         self.assertFalse(result._testRunEntered)
 
 
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/test/testmock/__main__.py b/Lib/unittest/test/testmock/__main__.py
new file mode 100644
index 0000000000..45c633a4ee
--- /dev/null
+++ b/Lib/unittest/test/testmock/__main__.py
@@ -0,0 +1,18 @@
+import os
+import unittest
+
+
+def load_tests(loader, standard_tests, pattern):
+    # top level directory cached on loader instance
+    this_dir = os.path.dirname(__file__)
+    pattern = pattern or "test*.py"
+    # We are inside unittest.test.testmock, so the top-level is three notches up
+    top_level_dir = os.path.dirname(os.path.dirname(os.path.dirname(this_dir)))
+    package_tests = loader.discover(start_dir=this_dir, pattern=pattern,
+                                    top_level_dir=top_level_dir)
+    standard_tests.addTests(package_tests)
+    return standard_tests
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/unittest/test/testmock/testcallable.py b/Lib/unittest/test/testmock/testcallable.py
index 7b2dd003ea..5390a4e10f 100644
--- a/Lib/unittest/test/testmock/testcallable.py
+++ b/Lib/unittest/test/testmock/testcallable.py
@@ -145,3 +145,7 @@ class TestCallable(unittest.TestCase):
         mock.wibble.assert_called_once_with()
 
         self.assertRaises(TypeError, mock.wibble, 'some',  'args')
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/unittest/test/testmock/testhelpers.py b/Lib/unittest/test/testmock/testhelpers.py
index a362a2f784..1dbc0b64ba 100644
--- a/Lib/unittest/test/testmock/testhelpers.py
+++ b/Lib/unittest/test/testmock/testhelpers.py
@@ -337,9 +337,10 @@ class SpecSignatureTest(unittest.TestCase):
 
 
     def test_basic(self):
-        for spec in (SomeClass, SomeClass()):
-            mock = create_autospec(spec)
-            self._check_someclass_mock(mock)
+        mock = create_autospec(SomeClass)
+        self._check_someclass_mock(mock)
+        mock = create_autospec(SomeClass())
+        self._check_someclass_mock(mock)
 
 
     def test_create_autospec_return_value(self):
@@ -576,10 +577,10 @@ class SpecSignatureTest(unittest.TestCase):
 
     def test_spec_inheritance_for_classes(self):
         class Foo(object):
-            def a(self):
+            def a(self, x):
                 pass
             class Bar(object):
-                def f(self):
+                def f(self, y):
                     pass
 
         class_mock = create_autospec(Foo)
@@ -587,26 +588,30 @@ class SpecSignatureTest(unittest.TestCase):
         self.assertIsNot(class_mock, class_mock())
 
         for this_mock in class_mock, class_mock():
-            this_mock.a()
-            this_mock.a.assert_called_with()
-            self.assertRaises(TypeError, this_mock.a, 'foo')
+            this_mock.a(x=5)
+            this_mock.a.assert_called_with(x=5)
+            this_mock.a.assert_called_with(5)
+            self.assertRaises(TypeError, this_mock.a, 'foo', 'bar')
             self.assertRaises(AttributeError, getattr, this_mock, 'b')
 
         instance_mock = create_autospec(Foo())
-        instance_mock.a()
-        instance_mock.a.assert_called_with()
-        self.assertRaises(TypeError, instance_mock.a, 'foo')
+        instance_mock.a(5)
+        instance_mock.a.assert_called_with(5)
+        instance_mock.a.assert_called_with(x=5)
+        self.assertRaises(TypeError, instance_mock.a, 'foo', 'bar')
         self.assertRaises(AttributeError, getattr, instance_mock, 'b')
 
         # The return value isn't isn't callable
         self.assertRaises(TypeError, instance_mock)
 
-        instance_mock.Bar.f()
-        instance_mock.Bar.f.assert_called_with()
+        instance_mock.Bar.f(6)
+        instance_mock.Bar.f.assert_called_with(6)
+        instance_mock.Bar.f.assert_called_with(y=6)
         self.assertRaises(AttributeError, getattr, instance_mock.Bar, 'g')
 
-        instance_mock.Bar().f()
-        instance_mock.Bar().f.assert_called_with()
+        instance_mock.Bar().f(6)
+        instance_mock.Bar().f.assert_called_with(6)
+        instance_mock.Bar().f.assert_called_with(y=6)
         self.assertRaises(AttributeError, getattr, instance_mock.Bar(), 'g')
 
 
@@ -663,12 +668,15 @@ class SpecSignatureTest(unittest.TestCase):
         self.assertRaises(TypeError, mock)
         mock(1, 2)
         mock.assert_called_with(1, 2)
+        mock.assert_called_with(1, b=2)
+        mock.assert_called_with(a=1, b=2)
 
         f.f = f
         mock = create_autospec(f)
         self.assertRaises(TypeError, mock.f)
         mock.f(3, 4)
         mock.f.assert_called_with(3, 4)
+        mock.f.assert_called_with(a=3, b=4)
 
 
     def test_skip_attributeerrors(self):
@@ -704,9 +712,13 @@ class SpecSignatureTest(unittest.TestCase):
         self.assertRaises(TypeError, mock)
         mock(1)
         mock.assert_called_once_with(1)
+        mock.assert_called_once_with(a=1)
+        self.assertRaises(AssertionError, mock.assert_called_once_with, 2)
 
         mock(4, 5)
         mock.assert_called_with(4, 5)
+        mock.assert_called_with(a=4, b=5)
+        self.assertRaises(AssertionError, mock.assert_called_with, a=5, b=4)
 
 
     def test_class_with_no_init(self):
@@ -719,24 +731,27 @@ class SpecSignatureTest(unittest.TestCase):
 
     def test_signature_callable(self):
         class Callable(object):
-            def __init__(self):
+            def __init__(self, x, y):
                 pass
             def __call__(self, a):
                 pass
 
         mock = create_autospec(Callable)
-        mock()
-        mock.assert_called_once_with()
+        mock(1, 2)
+        mock.assert_called_once_with(1, 2)
+        mock.assert_called_once_with(x=1, y=2)
         self.assertRaises(TypeError, mock, 'a')
 
-        instance = mock()
+        instance = mock(1, 2)
         self.assertRaises(TypeError, instance)
         instance(a='a')
+        instance.assert_called_once_with('a')
         instance.assert_called_once_with(a='a')
         instance('a')
         instance.assert_called_with('a')
+        instance.assert_called_with(a='a')
 
-        mock = create_autospec(Callable())
+        mock = create_autospec(Callable(1, 2))
         mock(a='a')
         mock.assert_called_once_with(a='a')
         self.assertRaises(TypeError, mock)
@@ -779,7 +794,11 @@ class SpecSignatureTest(unittest.TestCase):
                 pass
 
         a = create_autospec(Foo)
+        a.f(10)
+        a.f.assert_called_with(10)
+        a.f.assert_called_with(self=10)
         a.f(self=10)
+        a.f.assert_called_with(10)
         a.f.assert_called_with(self=10)
 
 
diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py
index cef5405fe9..20cc6541e6 100644
--- a/Lib/unittest/test/testmock/testmock.py
+++ b/Lib/unittest/test/testmock/testmock.py
@@ -25,6 +25,18 @@ class Iter(object):
     __next__ = next
 
 
+class Something(object):
+    def meth(self, a, b, c, d=None):
+        pass
+
+    @classmethod
+    def cmeth(cls, a, b, c, d=None):
+        pass
+
+    @staticmethod
+    def smeth(a, b, c, d=None):
+        pass
+
 
 class MockTest(unittest.TestCase):
 
@@ -273,6 +285,43 @@ class MockTest(unittest.TestCase):
         mock.assert_called_with(1, 2, 3, a='fish', b='nothing')
 
 
+    def test_assert_called_with_function_spec(self):
+        def f(a, b, c, d=None):
+            pass
+
+        mock = Mock(spec=f)
+
+        mock(1, b=2, c=3)
+        mock.assert_called_with(1, 2, 3)
+        mock.assert_called_with(a=1, b=2, c=3)
+        self.assertRaises(AssertionError, mock.assert_called_with,
+                          1, b=3, c=2)
+        # Expected call doesn't match the spec's signature
+        with self.assertRaises(AssertionError) as cm:
+            mock.assert_called_with(e=8)
+        self.assertIsInstance(cm.exception.__cause__, TypeError)
+
+
+    def test_assert_called_with_method_spec(self):
+        def _check(mock):
+            mock(1, b=2, c=3)
+            mock.assert_called_with(1, 2, 3)
+            mock.assert_called_with(a=1, b=2, c=3)
+            self.assertRaises(AssertionError, mock.assert_called_with,
+                              1, b=3, c=2)
+
+        mock = Mock(spec=Something().meth)
+        _check(mock)
+        mock = Mock(spec=Something.cmeth)
+        _check(mock)
+        mock = Mock(spec=Something().cmeth)
+        _check(mock)
+        mock = Mock(spec=Something.smeth)
+        _check(mock)
+        mock = Mock(spec=Something().smeth)
+        _check(mock)
+
+
     def test_assert_called_once_with(self):
         mock = Mock()
         mock()
@@ -297,6 +346,29 @@ class MockTest(unittest.TestCase):
         )
 
 
+    def test_assert_called_once_with_function_spec(self):
+        def f(a, b, c, d=None):
+            pass
+
+        mock = Mock(spec=f)
+
+        mock(1, b=2, c=3)
+        mock.assert_called_once_with(1, 2, 3)
+        mock.assert_called_once_with(a=1, b=2, c=3)
+        self.assertRaises(AssertionError, mock.assert_called_once_with,
+                          1, b=3, c=2)
+        # Expected call doesn't match the spec's signature
+        with self.assertRaises(AssertionError) as cm:
+            mock.assert_called_once_with(e=8)
+        self.assertIsInstance(cm.exception.__cause__, TypeError)
+        # Mock called more than once => always fails
+        mock(4, 5, 6)
+        self.assertRaises(AssertionError, mock.assert_called_once_with,
+                          1, 2, 3)
+        self.assertRaises(AssertionError, mock.assert_called_once_with,
+                          4, 5, 6)
+
+
     def test_attribute_access_returns_mocks(self):
         mock = Mock()
         something = mock.something
@@ -995,6 +1067,39 @@ class MockTest(unittest.TestCase):
                         )
 
 
+    def test_assert_has_calls_with_function_spec(self):
+        def f(a, b, c, d=None):
+            pass
+
+        mock = Mock(spec=f)
+
+        mock(1, b=2, c=3)
+        mock(4, 5, c=6, d=7)
+        mock(10, 11, c=12)
+        calls = [
+            ('', (1, 2, 3), {}),
+            ('', (4, 5, 6), {'d': 7}),
+            ((10, 11, 12), {}),
+            ]
+        mock.assert_has_calls(calls)
+        mock.assert_has_calls(calls, any_order=True)
+        mock.assert_has_calls(calls[1:])
+        mock.assert_has_calls(calls[1:], any_order=True)
+        mock.assert_has_calls(calls[:-1])
+        mock.assert_has_calls(calls[:-1], any_order=True)
+        # Reversed order
+        calls = list(reversed(calls))
+        with self.assertRaises(AssertionError):
+            mock.assert_has_calls(calls)
+        mock.assert_has_calls(calls, any_order=True)
+        with self.assertRaises(AssertionError):
+            mock.assert_has_calls(calls[1:])
+        mock.assert_has_calls(calls[1:], any_order=True)
+        with self.assertRaises(AssertionError):
+            mock.assert_has_calls(calls[:-1])
+        mock.assert_has_calls(calls[:-1], any_order=True)
+
+
     def test_assert_any_call(self):
         mock = Mock()
         mock(1, 2)
@@ -1021,6 +1126,26 @@ class MockTest(unittest.TestCase):
         )
 
 
+    def test_assert_any_call_with_function_spec(self):
+        def f(a, b, c, d=None):
+            pass
+
+        mock = Mock(spec=f)
+
+        mock(1, b=2, c=3)
+        mock(4, 5, c=6, d=7)
+        mock.assert_any_call(1, 2, 3)
+        mock.assert_any_call(a=1, b=2, c=3)
+        mock.assert_any_call(4, 5, 6, 7)
+        mock.assert_any_call(a=4, b=5, c=6, d=7)
+        self.assertRaises(AssertionError, mock.assert_any_call,
+                          1, b=3, c=2)
+        # Expected call doesn't match the spec's signature
+        with self.assertRaises(AssertionError) as cm:
+            mock.assert_any_call(e=8)
+        self.assertIsInstance(cm.exception.__cause__, TypeError)
+
+
     def test_mock_calls_create_autospec(self):
         def f(a, b):
             pass
@@ -1177,20 +1302,6 @@ class MockTest(unittest.TestCase):
             self.assertEqual(m.method_calls, [])
 
 
-    def test_attribute_deletion(self):
-        # this behaviour isn't *useful*, but at least it's now tested...
-        for Klass in Mock, MagicMock, NonCallableMagicMock, NonCallableMock:
-            m = Klass()
-            original = m.foo
-            m.foo = 3
-            del m.foo
-            self.assertEqual(m.foo, original)
-
-            new = m.foo = Mock()
-            del m.foo
-            self.assertEqual(m.foo, new)
-
-
     def test_mock_parents(self):
         for Klass in Mock, MagicMock:
             m = Klass()
@@ -1254,7 +1365,8 @@ class MockTest(unittest.TestCase):
 
 
     def test_attribute_deletion(self):
-        for mock in Mock(), MagicMock():
+        for mock in (Mock(), MagicMock(), NonCallableMagicMock(),
+                     NonCallableMock()):
             self.assertTrue(hasattr(mock, 'm'))
 
             del mock.m
@@ -1274,6 +1386,5 @@ class MockTest(unittest.TestCase):
             mock.foo
 
 
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/test/testmock/testpatch.py b/Lib/unittest/test/testmock/testpatch.py
index c1091b4e9b..c1bc34fa8c 100644
--- a/Lib/unittest/test/testmock/testpatch.py
+++ b/Lib/unittest/test/testmock/testpatch.py
@@ -1780,6 +1780,5 @@ class PatchTest(unittest.TestCase):
         self.assertIs(os.path, path)
 
 
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/test/testmock/testwith.py b/Lib/unittest/test/testmock/testwith.py
index 0a0cfad120..f54e051e94 100644
--- a/Lib/unittest/test/testmock/testwith.py
+++ b/Lib/unittest/test/testmock/testwith.py
@@ -172,5 +172,88 @@ class TestMockOpen(unittest.TestCase):
         self.assertEqual(result, 'foo')
 
 
+    def test_readline_data(self):
+        # Check that readline will return all the lines from the fake file
+        mock = mock_open(read_data='foo\nbar\nbaz\n')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            line1 = h.readline()
+            line2 = h.readline()
+            line3 = h.readline()
+        self.assertEqual(line1, 'foo\n')
+        self.assertEqual(line2, 'bar\n')
+        self.assertEqual(line3, 'baz\n')
+
+        # Check that we properly emulate a file that doesn't end in a newline
+        mock = mock_open(read_data='foo')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            result = h.readline()
+        self.assertEqual(result, 'foo')
+
+
+    def test_readlines_data(self):
+        # Test that emulating a file that ends in a newline character works
+        mock = mock_open(read_data='foo\nbar\nbaz\n')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            result = h.readlines()
+        self.assertEqual(result, ['foo\n', 'bar\n', 'baz\n'])
+
+        # Test that files without a final newline will also be correctly
+        # emulated
+        mock = mock_open(read_data='foo\nbar\nbaz')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            result = h.readlines()
+
+        self.assertEqual(result, ['foo\n', 'bar\n', 'baz'])
+
+
+    def test_mock_open_read_with_argument(self):
+        # At one point calling read with an argument was broken
+        # for mocks returned by mock_open
+        some_data = 'foo\nbar\nbaz'
+        mock = mock_open(read_data=some_data)
+        self.assertEqual(mock().read(10), some_data)
+
+
+    def test_interleaved_reads(self):
+        # Test that calling read, readline, and readlines pulls data
+        # sequentially from the data we preload with
+        mock = mock_open(read_data='foo\nbar\nbaz\n')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            line1 = h.readline()
+            rest = h.readlines()
+        self.assertEqual(line1, 'foo\n')
+        self.assertEqual(rest, ['bar\n', 'baz\n'])
+
+        mock = mock_open(read_data='foo\nbar\nbaz\n')
+        with patch('%s.open' % __name__, mock, create=True):
+            h = open('bar')
+            line1 = h.readline()
+            rest = h.read()
+        self.assertEqual(line1, 'foo\n')
+        self.assertEqual(rest, 'bar\nbaz\n')
+
+
+    def test_overriding_return_values(self):
+        mock = mock_open(read_data='foo')
+        handle = mock()
+
+        handle.read.return_value = 'bar'
+        handle.readline.return_value = 'bar'
+        handle.readlines.return_value = ['bar']
+
+        self.assertEqual(handle.read(), 'bar')
+        self.assertEqual(handle.readline(), 'bar')
+        self.assertEqual(handle.readlines(), ['bar'])
+
+        # call repeatedly to check that a StopIteration is not propagated
+        self.assertEqual(handle.readline(), 'bar')
+        self.assertEqual(handle.readline(), 'bar')
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/unittest/util.py b/Lib/unittest/util.py
index ccdf0b81fa..aee498fd0b 100644
--- a/Lib/unittest/util.py
+++ b/Lib/unittest/util.py
@@ -1,10 +1,47 @@
 """Various utility functions."""
 
 from collections import namedtuple, OrderedDict
+from os.path import commonprefix
 
 __unittest = True
 
 _MAX_LENGTH = 80
+_PLACEHOLDER_LEN = 12
+_MIN_BEGIN_LEN = 5
+_MIN_END_LEN = 5
+_MIN_COMMON_LEN = 5
+_MIN_DIFF_LEN = _MAX_LENGTH - \
+               (_MIN_BEGIN_LEN + _PLACEHOLDER_LEN + _MIN_COMMON_LEN +
+                _PLACEHOLDER_LEN + _MIN_END_LEN)
+assert _MIN_DIFF_LEN >= 0
+
+def _shorten(s, prefixlen, suffixlen):
+    skip = len(s) - prefixlen - suffixlen
+    if skip > _PLACEHOLDER_LEN:
+        s = '%s[%d chars]%s' % (s[:prefixlen], skip, s[len(s) - suffixlen:])
+    return s
+
+def _common_shorten_repr(*args):
+    args = tuple(map(safe_repr, args))
+    maxlen = max(map(len, args))
+    if maxlen <= _MAX_LENGTH:
+        return args
+
+    prefix = commonprefix(args)
+    prefixlen = len(prefix)
+
+    common_len = _MAX_LENGTH - \
+                 (maxlen - prefixlen + _MIN_BEGIN_LEN + _PLACEHOLDER_LEN)
+    if common_len > _MIN_COMMON_LEN:
+        assert _MIN_BEGIN_LEN + _PLACEHOLDER_LEN + _MIN_COMMON_LEN + \
+               (maxlen - prefixlen) < _MAX_LENGTH
+        prefix = _shorten(prefix, _MIN_BEGIN_LEN, common_len)
+        return tuple(prefix + s[prefixlen:] for s in args)
+
+    prefix = _shorten(prefix, _MIN_BEGIN_LEN, _MIN_COMMON_LEN)
+    return tuple(prefix + _shorten(s[prefixlen:], _MIN_DIFF_LEN, _MIN_END_LEN)
+                 for s in args)
+
 def safe_repr(obj, short=False):
     try:
         result = repr(obj)