让unittest框架在fail时自动截图的装饰器

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在使用unittest测试框架的时候，我们在判断测试结果的时候尝尝会使用断言。在使用appium框架时，我们可以直接使用assert语句进行判断。而我们在测试时，有时候会想要让代码在用例fail的时候自动生成截图。但是使用assert方法进行判断时，fail的用例只直接不执行之后的代码的，所以我们只能通过使用try…exception语句来让程序进行截图操作。

            try:                self.assertEqual(u'xxx','xxx','对比失败')            except AssertionError:            #调用ADB命令进行截图操作               path = os.getcwd() + "/screenshot"                 timestamp = time.strftime('%Y-%m-%d-%H-%M-%S', time.localtime(time.time()))                 os.popen("adb wait-for-device")                 os.popen("adb shell screencap -p /data/local/tmp/tmp.png")                 if not os.path.isdir(os.getcwd() + "/screenshot"):                     os.makedirs(path)                 os.popen("adb pull /data/local/tmp/tmp.png " + path + "/" + timestamp + ".png")                 os.popen("adb shell rm /data/local/tmp/tmp.png")             raise AssertionError,msg

但是这么实现之后，又觉得每一条assert语句都需要写一条try..exception.
是不是太麻烦了。于是就想到了之前看过装饰器。于是百度了解了一下原理。就开始尝试在unittest框架中给assert加上装饰器。来实现try..exception.

先找到assert语句块的位置。在C:\Python27\Lib\unittest目录里的case.py。打开文件。我进行了如下修改。

# -*- coding:utf-8 -*-# """Test case implementation"""import collectionsimport sysimport functoolsimport difflibimport pprintimport reimport typesimport warnings#这里引入了两个新模块import time import os

然后在class TestCase(object):中

class TestCase(object):    """A class whose instances are single test cases.    By default, the test code itself should be placed in a method named    'runTest'.    If the fixture may be used for many test cases, create as    many test methods as are needed. When instantiating such a TestCase    subclass, specify in the constructor arguments the name of the test method    that the instance is to execute.    Test authors should subclass TestCase for their own tests. Construction    and deconstruction of the test's environment ('fixture') can be    implemented by overriding the 'setUp' and 'tearDown' methods respectively.

在类里添加一个ADD装饰器。

############这里定义了装饰器add##########    def add(func):        def wrapper(self, first, second, msg=None):            try:                func(self, first, second, msg=None)            except AssertionError:#等待AssertionError                 path = os.getcwd() + "/screenshot"                 timestamp = time.strftime('%Y-%m-%d-%H-%M-%S', time.localtime(time.time()))                 os.popen("adb wait-for-device")                 os.popen("adb shell screencap -p /data/local/tmp/tmp.png")                 if not os.path.isdir(os.getcwd() + "/screenshot"):                     os.makedirs(path)                 os.popen("adb pull /data/local/tmp/tmp.png " + path + "/" + timestamp + ".png")                 os.popen("adb shell rm /data/local/tmp/tmp.png")            raise AssertionError,msg#抛出AssertionError和信息        return wrapper

    然后给以下方法加上装饰器

########################给方法加上装饰器    @add    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))            msg = self._formatMessage(msg, standardMsg)            raise self.failureException(msg)########################给方法加上装饰器    @add    def assertEqual(self, first, second, msg=None):        """Fail if the two objects are unequal as determined by the '=='           operator.        """        assertion_func = self._getAssertEqualityFunc(first, second)        assertion_func(first, second, msg=msg)########################给方法加上装饰器    @add    def assertNotEqual(self, first, second, msg=None):        """Fail if the two objects are equal as determined by the '!='           operator.        """        if not first != second:            msg = self._formatMessage(msg, '%s == %s' % (safe_repr(first),                                                          safe_repr(second)))            raise self.failureException(msg)

因为在判断中只用了assertEqual和assertNotEqual，所以装饰器只写了这个。
然后就可以实现了。

case.py全文：

# -*- coding:utf-8 -*-# """Test case implementation"""import collectionsimport sysimport functoolsimport difflibimport pprintimport reimport typesimport warningsimport timeimport osfrom . import resultfrom .util import (    strclass, safe_repr, unorderable_list_difference,    _count_diff_all_purpose, _count_diff_hashable)__unittest = TrueDIFF_OMITTED = ('\nDiff is %s characters long. '                 'Set self.maxDiff to None to see it.')class SkipTest(Exception):    """    Raise this exception in a test to skip it.    Usually you can use TestCase.skipTest() or one of the skipping decorators    instead of raising this directly.    """    passclass _ExpectedFailure(Exception):    """    Raise this when a test is expected to fail.    This is an implementation detail.    """    def __init__(self, exc_info):        super(_ExpectedFailure, self).__init__()        self.exc_info = exc_infoclass _UnexpectedSuccess(Exception):    """    The test was supposed to fail, but it didn't!    """    passdef _id(obj):    return objdef Myskip(func):    def RebackTest(self):        if self._resultForDoCleanups.failures or self._resultForDoCleanups.errors:            raise unittest.SkipTest("{} do not excute because {} is failed".format(func.__name__,self._resultForDoCleanups.failures[0][0]._testMethodName))        func(self)    return  RebackTestdef skip(reason):    """    Unconditionally skip a test.    """    def decorator(test_item):        if not isinstance(test_item, (type, types.ClassType)):            @functools.wraps(test_item)            def skip_wrapper(*args, **kwargs):                raise SkipTest(reason)            test_item = skip_wrapper        test_item.__unittest_skip__ = True        test_item.__unittest_skip_why__ = reason        return test_item    return decoratordef skipIf(condition, reason):    """    Skip a test if the condition is true.    """    if condition:        return skip(reason)    return _iddef skipUnless(condition, reason):    """    Skip a test unless the condition is true.    """    if not condition:        return skip(reason)    return _iddef expectedFailure(func):    @functools.wraps(func)    def wrapper(*args, **kwargs):        try:            func(*args, **kwargs)        except Exception:            raise _ExpectedFailure(sys.exc_info())        raise _UnexpectedSuccess    return wrapperclass _AssertRaisesContext(object):    """A context manager used to implement TestCase.assertRaises* methods."""    def __init__(self, expected, test_case, expected_regexp=None):        self.expected = expected        self.failureException = test_case.failureException        self.expected_regexp = expected_regexp    def __enter__(self):        return self    def __exit__(self, exc_type, exc_value, tb):        if exc_type is None:            try:                exc_name = self.expected.__name__            except AttributeError:                exc_name = str(self.expected)            raise self.failureException(                "{0} not raised".format(exc_name))        if not issubclass(exc_type, self.expected):            # let unexpected exceptions pass through            return False        self.exception = exc_value # store for later retrieval        if self.expected_regexp is None:            return True        expected_regexp = self.expected_regexp        if not expected_regexp.search(str(exc_value)):            raise self.failureException('"%s" does not match "%s"' %                     (expected_regexp.pattern, str(exc_value)))        return Trueclass TestCase(object):    """A class whose instances are single test cases.    By default, the test code itself should be placed in a method named    'runTest'.    If the fixture may be used for many test cases, create as    many test methods as are needed. When instantiating such a TestCase    subclass, specify in the constructor arguments the name of the test method    that the instance is to execute.    Test authors should subclass TestCase for their own tests. Construction    and deconstruction of the test's environment ('fixture') can be    implemented by overriding the 'setUp' and 'tearDown' methods respectively.    If it is necessary to override the __init__ method, the base class    __init__ method must always be called. It is important that subclasses    should not change the signature of their __init__ method, since instances    of the classes are instantiated automatically by parts of the framework    in order to be run.    When subclassing TestCase, you can set these attributes:    * failureException: determines which exception will be raised when        the instance's assertion methods fail; test methods raising this        exception will be deemed to have 'failed' rather than 'errored'.    * longMessage: determines whether long messages (including repr of        objects used in assert methods) will be printed on failure in *addition*        to any explicit message passed.    * maxDiff: sets the maximum length of a diff in failure messages        by assert methods using difflib. It is looked up as an instance        attribute so can be configured by individual tests if required.    """    failureException = AssertionError    longMessage = False    maxDiff = 80*8    # If a string is longer than _diffThreshold, use normal comparison instead    # of difflib.  See #11763.    _diffThreshold = 2**16    # Attribute used by TestSuite for classSetUp    _classSetupFailed = False    def __init__(self, methodName='runTest'):        """Create an instance of the class that will use the named test           method when executed. Raises a ValueError if the instance does           not have a method with the specified name.        """        self._testMethodName = methodName        self._resultForDoCleanups = None        try:            testMethod = getattr(self, methodName)        except AttributeError:            raise ValueError("no such test method in %s: %s" %                  (self.__class__, methodName))        self._testMethodDoc = testMethod.__doc__        self._cleanups = []        # Map types to custom assertEqual functions that will compare        # instances of said type in more detail to generate a more useful        # error message.        self._type_equality_funcs = {}        self.addTypeEqualityFunc(dict, 'assertDictEqual')        self.addTypeEqualityFunc(list, 'assertListEqual')        self.addTypeEqualityFunc(tuple, 'assertTupleEqual')        self.addTypeEqualityFunc(set, 'assertSetEqual')        self.addTypeEqualityFunc(frozenset, 'assertSetEqual')        try:            self.addTypeEqualityFunc(unicode, 'assertMultiLineEqual')        except NameError:            # No unicode support in this build            pass    def addTypeEqualityFunc(self, typeobj, function):        """Add a type specific assertEqual style function to compare a type.        This method is for use by TestCase subclasses that need to register        their own type equality functions to provide nicer error messages.        Args:            typeobj: The data type to call this function on when both values                    are of the same type in assertEqual().            function: The callable taking two arguments and an optional                    msg= argument that raises self.failureException with a                    useful error message when the two arguments are not equal.        """        self._type_equality_funcs[typeobj] = function    def addCleanup(self, function, *args, **kwargs):        """Add a function, with arguments, to be called when the test is        completed. Functions added are called on a LIFO basis and are        called after tearDown on test failure or success.        Cleanup items are called even if setUp fails (unlike tearDown)."""        self._cleanups.append((function, args, kwargs))    def setUp(self):        "Hook method for setting up the test fixture before exercising it."        pass    def tearDown(self):        "Hook method for deconstructing the test fixture after testing it."        pass    @classmethod    def setUpClass(cls):        "Hook method for setting up class fixture before running tests in the class."    @classmethod    def tearDownClass(cls):        "Hook method for deconstructing the class fixture after running all tests in the class."    def countTestCases(self):        return 1    def defaultTestResult(self):        return result.TestResult()    def shortDescription(self):        """Returns a one-line description of the test, or None if no        description has been provided.        The default implementation of this method returns the first line of        the specified test method's docstring.        """        doc = self._testMethodDoc        return doc and doc.split("\n")[0].strip() or None    def id(self):        return "%s.%s" % (strclass(self.__class__), self._testMethodName)    def __eq__(self, other):        if type(self) is not type(other):            return NotImplemented        return self._testMethodName == other._testMethodName    def __ne__(self, other):        return not self == other    def __hash__(self):        return hash((type(self), self._testMethodName))    def __str__(self):        return "%s (%s)" % (self._testMethodName, strclass(self.__class__))    def __repr__(self):        return "<%s testMethod=%s>" % \               (strclass(self.__class__), self._testMethodName)    def _addSkip(self, result, reason):        addSkip = getattr(result, 'addSkip', None)        if addSkip is not None:            addSkip(self, reason)        else:            warnings.warn("TestResult has no addSkip method, skips not reported",                          RuntimeWarning, 2)            result.addSuccess(self)    def run(self, result=None):        orig_result = result        if result is None:            result = self.defaultTestResult()            startTestRun = getattr(result, 'startTestRun', None)            if startTestRun is not None:                startTestRun()        self._resultForDoCleanups = result        result.startTest(self)        testMethod = getattr(self, self._testMethodName)        if (getattr(self.__class__, "__unittest_skip__", False) or            getattr(testMethod, "__unittest_skip__", False)):            # If the class or method was skipped.            try:                skip_why = (getattr(self.__class__, '__unittest_skip_why__', '')                            or getattr(testMethod, '__unittest_skip_why__', ''))                self._addSkip(result, skip_why)            finally:                result.stopTest(self)            return        try:            success = False            try:                self.setUp()            except SkipTest as e:                self._addSkip(result, str(e))            except KeyboardInterrupt:                raise            except:                result.addError(self, sys.exc_info())            else:                try:                    testMethod()                except KeyboardInterrupt:                    raise                except self.failureException:                    result.addFailure(self, sys.exc_info())                except _ExpectedFailure as e:                    addExpectedFailure = getattr(result, 'addExpectedFailure', None)                    if addExpectedFailure is not None:                        addExpectedFailure(self, e.exc_info)                    else:                        warnings.warn("TestResult has no addExpectedFailure method, reporting as passes",                                      RuntimeWarning)                        result.addSuccess(self)                except _UnexpectedSuccess:                    addUnexpectedSuccess = getattr(result, 'addUnexpectedSuccess', None)                    if addUnexpectedSuccess is not None:                        addUnexpectedSuccess(self)                    else:                        warnings.warn("TestResult has no addUnexpectedSuccess method, reporting as failures",                                      RuntimeWarning)                        result.addFailure(self, sys.exc_info())                except SkipTest as e:                    self._addSkip(result, str(e))                except:                    result.addError(self, sys.exc_info())                else:                    success = True                try:                    self.tearDown()                except KeyboardInterrupt:                    raise                except:                    result.addError(self, sys.exc_info())                    success = False            cleanUpSuccess = self.doCleanups()            success = success and cleanUpSuccess            if success:                result.addSuccess(self)        finally:            result.stopTest(self)            if orig_result is None:                stopTestRun = getattr(result, 'stopTestRun', None)                if stopTestRun is not None:                    stopTestRun()    def doCleanups(self):        """Execute all cleanup functions. Normally called for you after        tearDown."""        result = self._resultForDoCleanups        ok = True        while self._cleanups:            function, args, kwargs = self._cleanups.pop(-1)            try:                function(*args, **kwargs)            except KeyboardInterrupt:                raise            except:                ok = False                result.addError(self, sys.exc_info())        return ok    def __call__(self, *args, **kwds):        return self.run(*args, **kwds)    def debug(self):        """Run the test without collecting errors in a TestResult"""        self.setUp()        getattr(self, self._testMethodName)()        self.tearDown()        while self._cleanups:            function, args, kwargs = self._cleanups.pop(-1)            function(*args, **kwargs)    def skipTest(self, reason):        """Skip this test."""        raise SkipTest(reason)    def fail(self, msg=None):        """Fail immediately, with the given message."""        raise self.failureException(msg)    def assertFalse(self, expr, msg=None):        """Check that the expression is false."""        if expr:            msg = self._formatMessage(msg, "%s is not false" % safe_repr(expr))            raise self.failureException(msg)    def assertTrue(self, expr, msg=None):        """Check that the expression is true."""        if not expr:            msg = self._formatMessage(msg, "%s is not true" % safe_repr(expr))            raise self.failureException(msg)    def _formatMessage(self, msg, standardMsg):        """Honour the longMessage attribute when generating failure messages.        If longMessage is False this means:        * Use only an explicit message if it is provided        * Otherwise use the standard message for the assert        If longMessage is True:        * Use the standard message        * If an explicit message is provided, plus ' : ' and the explicit message        """        if not self.longMessage:            return msg or standardMsg        if msg is None:            return standardMsg        try:            # don't switch to '{}' formatting in Python 2.X            # it changes the way unicode input is handled            return '%s : %s' % (standardMsg, msg)        except UnicodeDecodeError:            return  '%s : %s' % (safe_repr(standardMsg), safe_repr(msg))    def assertRaises(self, excClass, callableObj=None, *args, **kwargs):        """Fail unless an exception of class excClass is raised           by callableObj when invoked with arguments args and keyword           arguments kwargs. If a different type of exception is           raised, it will not be caught, and the test case will be           deemed to have suffered an error, exactly as for an           unexpected exception.           If called with callableObj omitted or None, will return a           context object used like this::                with self.assertRaises(SomeException):                    do_something()           The context manager keeps a reference to the exception as           the 'exception' attribute. This allows you to inspect the           exception after the assertion::               with self.assertRaises(SomeException) as cm:                   do_something()               the_exception = cm.exception               self.assertEqual(the_exception.error_code, 3)        """        context = _AssertRaisesContext(excClass, self)        if callableObj is None:            return context        with context:            callableObj(*args, **kwargs)    def _getAssertEqualityFunc(self, first, second):        """Get a detailed comparison function for the types of the two args.        Returns: A callable accepting (first, second, msg=None) that will        raise a failure exception if first != second with a useful human        readable error message for those types.        """        #        # NOTE(gregory.p.smith): I considered isinstance(first, type(second))        # and vice versa.  I opted for the conservative approach in case        # subclasses are not intended to be compared in detail to their super        # class instances using a type equality func.  This means testing        # subtypes won't automagically use the detailed comparison.  Callers        # should use their type specific assertSpamEqual method to compare        # subclasses if the detailed comparison is desired and appropriate.        # See the discussion in http://bugs.python.org/issue2578.        #        if type(first) is type(second):            asserter = self._type_equality_funcs.get(type(first))            if asserter is not None:                if isinstance(asserter, basestring):                    asserter = getattr(self, asserter)                return asserter        return self._baseAssertEqual    ############这里定义了装饰器add##########    def add(func):        PATH = lambda p: os.path.abspath(p)        def wrapper(self, first, second, msg=None):            try:                func(self, first, second, msg=None)            except AssertionError:                path = PATH(os.getcwd() + "/screenshot")                timestamp = time.strftime('%Y-%m-%d-%H-%M-%S', time.localtime(time.time()))                os.popen("adb wait-for-device")                os.popen("adb shell screencap -p /data/local/tmp/tmp.png")                if not os.path.isdir(PATH(os.getcwd() + "/screenshot")):                    os.makedirs(path)                os.popen("adb pull /data/local/tmp/tmp.png " + PATH(path + "/" + timestamp + ".png"))                os.popen("adb shell rm /data/local/tmp/tmp.png")                #打印出路径                print  'screenshot:',timestamp , '.png'                raise AssertionError,msg        return wrapper    ########################给方法加上装饰器    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))            msg = self._formatMessage(msg, standardMsg)            raise self.failureException(msg)    @add    def assertEqual(self, first, second, msg=None):        """Fail if the two objects are unequal as determined by the '=='           operator.        """        assertion_func = self._getAssertEqualityFunc(first, second)        assertion_func(first, second, msg=msg)    @add    def assertNotEqual(self, first, second, msg=None):        """Fail if the two objects are equal as determined by the '!='           operator.        """        if not first != second:            msg = self._formatMessage(msg, '%s == %s' % (safe_repr(first),                                                          safe_repr(second)))            raise self.failureException(msg)    def assertAlmostEqual(self, first, second, places=None, msg=None, delta=None):        """Fail if the two objects are unequal as determined by their           difference rounded to the given number of decimal places           (default 7) and comparing to zero, or by comparing that the           between the two objects is more than the given delta.           Note that decimal places (from zero) are usually not the same           as significant digits (measured from the most signficant digit).           If the two objects compare equal then they will automatically           compare almost equal.        """        if first == second:            # shortcut            return        if delta is not None and places is not None:            raise TypeError("specify delta or places not both")        if delta is not None:            if abs(first - second) <= delta:                return            standardMsg = '%s != %s within %s delta' % (safe_repr(first),                                                        safe_repr(second),                                                        safe_repr(delta))        else:            if places is None:                places = 7            if round(abs(second-first), places) == 0:                return            standardMsg = '%s != %s within %r places' % (safe_repr(first),                                                          safe_repr(second),                                                          places)        msg = self._formatMessage(msg, standardMsg)        raise self.failureException(msg)    def assertNotAlmostEqual(self, first, second, places=None, msg=None, delta=None):        """Fail if the two objects are equal as determined by their           difference rounded to the given number of decimal places           (default 7) and comparing to zero, or by comparing that the           between the two objects is less than the given delta.           Note that decimal places (from zero) are usually not the same           as significant digits (measured from the most signficant digit).           Objects that are equal automatically fail.        """        if delta is not None and places is not None:            raise TypeError("specify delta or places not both")        if delta is not None:            if not (first == second) and abs(first - second) > delta:                return            standardMsg = '%s == %s within %s delta' % (safe_repr(first),                                                        safe_repr(second),                                                        safe_repr(delta))        else:            if places is None:                places = 7            if not (first == second) and round(abs(second-first), places) != 0:                return            standardMsg = '%s == %s within %r places' % (safe_repr(first),                                                         safe_repr(second),                                                         places)        msg = self._formatMessage(msg, standardMsg)        raise self.failureException(msg)    # Synonyms for assertion methods    # The plurals are undocumented.  Keep them that way to discourage use.    # Do not add more.  Do not remove.    # Going through a deprecation cycle on these would annoy many people.    assertEquals = assertEqual    assertNotEquals = assertNotEqual    assertAlmostEquals = assertAlmostEqual    assertNotAlmostEquals = assertNotAlmostEqual    assert_ = assertTrue    # These fail* assertion method names are pending deprecation and will    # be a DeprecationWarning in 3.2; http://bugs.python.org/issue2578    def _deprecate(original_func):        def deprecated_func(*args, **kwargs):            warnings.warn(                'Please use {0} instead.'.format(original_func.__name__),                PendingDeprecationWarning, 2)            return original_func(*args, **kwargs)        return deprecated_func    failUnlessEqual = _deprecate(assertEqual)    failIfEqual = _deprecate(assertNotEqual)    failUnlessAlmostEqual = _deprecate(assertAlmostEqual)    failIfAlmostEqual = _deprecate(assertNotAlmostEqual)    failUnless = _deprecate(assertTrue)    failUnlessRaises = _deprecate(assertRaises)    failIf = _deprecate(assertFalse)    def assertSequenceEqual(self, seq1, seq2, msg=None, seq_type=None):        """An equality assertion for ordered sequences (like lists and tuples).        For the purposes of this function, a valid ordered sequence type is one        which can be indexed, has a length, and has an equality operator.        Args:            seq1: The first sequence to compare.            seq2: The second sequence to compare.            seq_type: The expected datatype of the sequences, or None if no                    datatype should be enforced.            msg: Optional message to use on failure instead of a list of                    differences.        """        if seq_type is not None:            seq_type_name = seq_type.__name__            if not isinstance(seq1, seq_type):                raise self.failureException('First sequence is not a %s: %s'                                        % (seq_type_name, safe_repr(seq1)))            if not isinstance(seq2, seq_type):                raise self.failureException('Second sequence is not a %s: %s'                                        % (seq_type_name, safe_repr(seq2)))        else:            seq_type_name = "sequence"        differing = None        try:            len1 = len(seq1)        except (TypeError, NotImplementedError):            differing = 'First %s has no length.    Non-sequence?' % (                    seq_type_name)        if differing is None:            try:                len2 = len(seq2)            except (TypeError, NotImplementedError):                differing = 'Second %s has no length.    Non-sequence?' % (                        seq_type_name)        if differing is None:            if seq1 == seq2:                return            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            for i in xrange(min(len1, len2)):                try:                    item1 = seq1[i]                except (TypeError, IndexError, NotImplementedError):                    differing += ('\nUnable to index element %d of first %s\n' %                                 (i, seq_type_name))                    break                try:                    item2 = seq2[i]                except (TypeError, IndexError, NotImplementedError):                    differing += ('\nUnable to index element %d of second %s\n' %                                 (i, seq_type_name))                    break                if item1 != item2:                    differing += ('\nFirst differing element %d:\n%s\n%s\n' %                                 (i, safe_repr(item1), safe_repr(item2)))                    break            else:                if (len1 == len2 and seq_type is None and                    type(seq1) != type(seq2)):                    # The sequences are the same, but have differing types.                    return            if len1 > len2:                differing += ('\nFirst %s contains %d additional '                             'elements.\n' % (seq_type_name, len1 - len2))                try:                    differing += ('First extra element %d:\n%s\n' %                                  (len2, safe_repr(seq1[len2])))                except (TypeError, IndexError, NotImplementedError):                    differing += ('Unable to index element %d '                                  'of first %s\n' % (len2, seq_type_name))            elif len1 < len2:                differing += ('\nSecond %s contains %d additional '                             'elements.\n' % (seq_type_name, len2 - len1))                try:                    differing += ('First extra element %d:\n%s\n' %                                  (len1, safe_repr(seq2[len1])))                except (TypeError, IndexError, NotImplementedError):                    differing += ('Unable to index element %d '                                  'of second %s\n' % (len1, seq_type_name))        standardMsg = differing        diffMsg = '\n' + '\n'.join(            difflib.ndiff(pprint.pformat(seq1).splitlines(),                          pprint.pformat(seq2).splitlines()))        standardMsg = self._truncateMessage(standardMsg, diffMsg)        msg = self._formatMessage(msg, standardMsg)        self.fail(msg)    def _truncateMessage(self, message, diff):        max_diff = self.maxDiff        if max_diff is None or len(diff) <= max_diff:            return message + diff        return message + (DIFF_OMITTED % len(diff))    def assertListEqual(self, list1, list2, msg=None):        """A list-specific equality assertion.        Args:            list1: The first list to compare.            list2: The second list to compare.            msg: Optional message to use on failure instead of a list of                    differences.        """        self.assertSequenceEqual(list1, list2, msg, seq_type=list)    def assertTupleEqual(self, tuple1, tuple2, msg=None):        """A tuple-specific equality assertion.        Args:            tuple1: The first tuple to compare.            tuple2: The second tuple to compare.            msg: Optional message to use on failure instead of a list of                    differences.        """        self.assertSequenceEqual(tuple1, tuple2, msg, seq_type=tuple)    def assertSetEqual(self, set1, set2, msg=None):        """A set-specific equality assertion.        Args:            set1: The first set to compare.            set2: The second set to compare.            msg: Optional message to use on failure instead of a list of                    differences.        assertSetEqual uses ducktyping to support different types of sets, and        is optimized for sets specifically (parameters must support a        difference method).        """        try:            difference1 = set1.difference(set2)        except TypeError, e:            self.fail('invalid type when attempting set difference: %s' % e)        except AttributeError, e:            self.fail('first argument does not support set difference: %s' % e)        try:            difference2 = set2.difference(set1)        except TypeError, e:            self.fail('invalid type when attempting set difference: %s' % e)        except AttributeError, e:            self.fail('second argument does not support set difference: %s' % e)        if not (difference1 or difference2):            return        lines = []        if difference1:            lines.append('Items in the first set but not the second:')            for item in difference1:                lines.append(repr(item))        if difference2:            lines.append('Items in the second set but not the first:')            for item in difference2:                lines.append(repr(item))        standardMsg = '\n'.join(lines)        self.fail(self._formatMessage(msg, standardMsg))    def assertIn(self, member, container, msg=None):        """Just like self.assertTrue(a in b), but with a nicer default message."""        if member not in container:            standardMsg = '%s not found in %s' % (safe_repr(member),                                                  safe_repr(container))            self.fail(self._formatMessage(msg, standardMsg))    def assertNotIn(self, member, container, msg=None):        """Just like self.assertTrue(a not in b), but with a nicer default message."""        if member in container:            standardMsg = '%s unexpectedly found in %s' % (safe_repr(member),                                                        safe_repr(container))            self.fail(self._formatMessage(msg, standardMsg))    def assertIs(self, expr1, expr2, msg=None):        """Just like self.assertTrue(a is b), but with a nicer default message."""        if expr1 is not expr2:            standardMsg = '%s is not %s' % (safe_repr(expr1),                                             safe_repr(expr2))            self.fail(self._formatMessage(msg, standardMsg))    def assertIsNot(self, expr1, expr2, msg=None):        """Just like self.assertTrue(a is not b), but with a nicer default message."""        if expr1 is expr2:            standardMsg = 'unexpectedly identical: %s' % (safe_repr(expr1),)            self.fail(self._formatMessage(msg, standardMsg))    def assertDictEqual(self, d1, d2, msg=None):        self.assertIsInstance(d1, dict, 'First argument is not a dictionary')        self.assertIsInstance(d2, dict, 'Second argument is not a dictionary')        if d1 != d2:            standardMsg = '%s != %s' % (safe_repr(d1, True), safe_repr(d2, True))            diff = ('\n' + '\n'.join(difflib.ndiff(                           pprint.pformat(d1).splitlines(),                           pprint.pformat(d2).splitlines())))            standardMsg = self._truncateMessage(standardMsg, diff)            self.fail(self._formatMessage(msg, standardMsg))    def assertDictContainsSubset(self, expected, actual, msg=None):        """Checks whether actual is a superset of expected."""        missing = []        mismatched = []        for key, value in expected.iteritems():            if key not in actual:                missing.append(key)            elif value != actual[key]:                mismatched.append('%s, expected: %s, actual: %s' %                                  (safe_repr(key), safe_repr(value),                                   safe_repr(actual[key])))        if not (missing or mismatched):            return        standardMsg = ''        if missing:            standardMsg = 'Missing: %s' % ','.join(safe_repr(m) for m in                                                    missing)        if mismatched:            if standardMsg:                standardMsg += '; '            standardMsg += 'Mismatched values: %s' % ','.join(mismatched)        self.fail(self._formatMessage(msg, standardMsg))    def assertItemsEqual(self, expected_seq, actual_seq, msg=None):        """An unordered sequence specific comparison. It asserts that        actual_seq and expected_seq have the same element counts.        Equivalent to::            self.assertEqual(Counter(iter(actual_seq)),                             Counter(iter(expected_seq)))        Asserts that each element has the same count in both sequences.        Example:            - [0, 1, 1] and [1, 0, 1] compare equal.            - [0, 0, 1] and [0, 1] compare unequal.        """        first_seq, second_seq = list(expected_seq), list(actual_seq)        with warnings.catch_warnings():            if sys.py3kwarning:                # Silence Py3k warning raised during the sorting                for _msg in ["(code|dict|type) inequality comparisons",                             "builtin_function_or_method order comparisons",                             "comparing unequal types"]:                    warnings.filterwarnings("ignore", _msg, DeprecationWarning)            try:                first = collections.Counter(first_seq)                second = collections.Counter(second_seq)            except TypeError:                # Handle case with unhashable elements                differences = _count_diff_all_purpose(first_seq, second_seq)            else:                if first == second:                    return                differences = _count_diff_hashable(first_seq, second_seq)        if differences:            standardMsg = 'Element counts were not equal:\n'            lines = ['First has %d, Second has %d:  %r' % diff for diff in differences]            diffMsg = '\n'.join(lines)            standardMsg = self._truncateMessage(standardMsg, diffMsg)            msg = self._formatMessage(msg, standardMsg)            self.fail(msg)    def assertMultiLineEqual(self, first, second, msg=None):        """Assert that two multi-line strings are equal."""        self.assertIsInstance(first, basestring,                'First argument is not a string')        self.assertIsInstance(second, basestring,                'Second argument is not a string')        if first != second:            # don't use difflib if the strings are too long            if (len(first) > self._diffThreshold or                len(second) > self._diffThreshold):                self._baseAssertEqual(first, second, msg)            firstlines = first.splitlines(True)            secondlines = second.splitlines(True)            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))            diff = '\n' + ''.join(difflib.ndiff(firstlines, secondlines))            standardMsg = self._truncateMessage(standardMsg, diff)            self.fail(self._formatMessage(msg, standardMsg))    @add    def assertLess(self, a, b, msg=None):        """Just like self.assertTrue(a < b), but with a nicer default message."""        if not a < b:            standardMsg = '%s not less than %s' % (safe_repr(a), safe_repr(b))            self.fail(self._formatMessage(msg, standardMsg))    def assertLessEqual(self, a, b, msg=None):        """Just like self.assertTrue(a <= b), but with a nicer default message."""        if not a <= b:            standardMsg = '%s not less than or equal to %s' % (safe_repr(a), safe_repr(b))            self.fail(self._formatMessage(msg, standardMsg))    def assertGreater(self, a, b, msg=None):        """Just like self.assertTrue(a > b), but with a nicer default message."""        if not a > b:            standardMsg = '%s not greater than %s' % (safe_repr(a), safe_repr(b))            self.fail(self._formatMessage(msg, standardMsg))    def assertGreaterEqual(self, a, b, msg=None):        """Just like self.assertTrue(a >= b), but with a nicer default message."""        if not a >= b:            standardMsg = '%s not greater than or equal to %s' % (safe_repr(a), safe_repr(b))            self.fail(self._formatMessage(msg, standardMsg))    def assertIsNone(self, obj, msg=None):        """Same as self.assertTrue(obj is None), with a nicer default message."""        if obj is not None:            standardMsg = '%s is not None' % (safe_repr(obj),)            self.fail(self._formatMessage(msg, standardMsg))    def assertIsNotNone(self, obj, msg=None):        """Included for symmetry with assertIsNone."""        if obj is None:            standardMsg = 'unexpectedly None'            self.fail(self._formatMessage(msg, standardMsg))    def assertIsInstance(self, obj, cls, msg=None):        """Same as self.assertTrue(isinstance(obj, cls)), with a nicer        default message."""        if not isinstance(obj, cls):            standardMsg = '%s is not an instance of %r' % (safe_repr(obj), cls)            self.fail(self._formatMessage(msg, standardMsg))    def assertNotIsInstance(self, obj, cls, msg=None):        """Included for symmetry with assertIsInstance."""        if isinstance(obj, cls):            standardMsg = '%s is an instance of %r' % (safe_repr(obj), cls)            self.fail(self._formatMessage(msg, standardMsg))    def assertRaisesRegexp(self, expected_exception, expected_regexp,                           callable_obj=None, *args, **kwargs):        """Asserts that the message in a raised exception matches a regexp.        Args:            expected_exception: Exception class expected to be raised.            expected_regexp: Regexp (re pattern object or string) expected                    to be found in error message.            callable_obj: Function to be called.            args: Extra args.            kwargs: Extra kwargs.        """        if expected_regexp is not None:            expected_regexp = re.compile(expected_regexp)        context = _AssertRaisesContext(expected_exception, self, expected_regexp)        if callable_obj is None:            return context        with context:            callable_obj(*args, **kwargs)    def assertRegexpMatches(self, text, expected_regexp, msg=None):        """Fail the test unless the text matches the regular expression."""        if isinstance(expected_regexp, basestring):            expected_regexp = re.compile(expected_regexp)        if not expected_regexp.search(text):            msg = msg or "Regexp didn't match"            msg = '%s: %r not found in %r' % (msg, expected_regexp.pattern, text)            raise self.failureException(msg)    def assertNotRegexpMatches(self, text, unexpected_regexp, msg=None):        """Fail the test if the text matches the regular expression."""        if isinstance(unexpected_regexp, basestring):            unexpected_regexp = re.compile(unexpected_regexp)        match = unexpected_regexp.search(text)        if match:            msg = msg or "Regexp matched"            msg = '%s: %r matches %r in %r' % (msg,                                               text[match.start():match.end()],                                               unexpected_regexp.pattern,                                               text)            raise self.failureException(msg)class FunctionTestCase(TestCase):    """A test case that wraps a test function.    This is useful for slipping pre-existing test functions into the    unittest framework. Optionally, set-up and tidy-up functions can be    supplied. As with TestCase, the tidy-up ('tearDown') function will    always be called if the set-up ('setUp') function ran successfully.    """    def __init__(self, testFunc, setUp=None, tearDown=None, description=None):        super(FunctionTestCase, self).__init__()        self._setUpFunc = setUp        self._tearDownFunc = tearDown        self._testFunc = testFunc        self._description = description    def setUp(self):        if self._setUpFunc is not None:            self._setUpFunc()    def tearDown(self):        if self._tearDownFunc is not None:            self._tearDownFunc()    def runTest(self):        self._testFunc()    def id(self):        return self._testFunc.__name__    def __eq__(self, other):        if not isinstance(other, self.__class__):            return NotImplemented        return self._setUpFunc == other._setUpFunc and \               self._tearDownFunc == other._tearDownFunc and \               self._testFunc == other._testFunc and \               self._description == other._description    def __ne__(self, other):        return not self == other    def __hash__(self):        return hash((type(self), self._setUpFunc, self._tearDownFunc,                     self._testFunc, self._description))    def __str__(self):        return "%s (%s)" % (strclass(self.__class__),                            self._testFunc.__name__)    def __repr__(self):        return "<%s tec=%s>" % (strclass(self.__class__),                                     self._testFunc)    def shortDescription(self):        if self._description is not None:            return self._description        doc = self._testFunc.__doc__        return doc and doc.split("\n")[0].strip() or None