# Copyright (c) 2008-2011 testtools developers. See LICENSE for details. """Test case related stuff.""" __metaclass__ = type __all__ = [ 'clone_test_with_new_id', 'ExpectedException', 'gather_details', 'run_test_with', 'skip', 'skipIf', 'skipUnless', 'TestCase', ] import copy import itertools import sys import types import unittest from testtools import ( content, try_import, ) from testtools.compat import ( advance_iterator, reraise, ) from testtools.matchers import ( Annotate, Contains, Equals, MatchesAll, MatchesException, MismatchError, Is, IsInstance, Not, Raises, ) from testtools.monkey import patch from testtools.runtest import RunTest from testtools.testresult import ( ExtendedToOriginalDecorator, TestResult, ) wraps = try_import('functools.wraps') class TestSkipped(Exception): """Raised within TestCase.run() when a test is skipped.""" testSkipped = try_import('unittest2.case.SkipTest', TestSkipped) TestSkipped = try_import('unittest.case.SkipTest', TestSkipped) class _UnexpectedSuccess(Exception): """An unexpected success was raised. Note that this exception is private plumbing in testtools' testcase module. """ _UnexpectedSuccess = try_import( 'unittest2.case._UnexpectedSuccess', _UnexpectedSuccess) _UnexpectedSuccess = try_import( 'unittest.case._UnexpectedSuccess', _UnexpectedSuccess) class _ExpectedFailure(Exception): """An expected failure occured. Note that this exception is private plumbing in testtools' testcase module. """ _ExpectedFailure = try_import( 'unittest2.case._ExpectedFailure', _ExpectedFailure) _ExpectedFailure = try_import( 'unittest.case._ExpectedFailure', _ExpectedFailure) def run_test_with(test_runner, **kwargs): """Decorate a test as using a specific ``RunTest``. e.g.:: @run_test_with(CustomRunner, timeout=42) def test_foo(self): self.assertTrue(True) The returned decorator works by setting an attribute on the decorated function. `TestCase.__init__` looks for this attribute when deciding on a ``RunTest`` factory. If you wish to use multiple decorators on a test method, then you must either make this one the top-most decorator, or you must write your decorators so that they update the wrapping function with the attributes of the wrapped function. The latter is recommended style anyway. ``functools.wraps``, ``functools.wrapper`` and ``twisted.python.util.mergeFunctionMetadata`` can help you do this. :param test_runner: A ``RunTest`` factory that takes a test case and an optional list of exception handlers. See ``RunTest``. :param kwargs: Keyword arguments to pass on as extra arguments to 'test_runner'. :return: A decorator to be used for marking a test as needing a special runner. """ def decorator(function): # Set an attribute on 'function' which will inform TestCase how to # make the runner. function._run_test_with = ( lambda case, handlers=None: test_runner(case, handlers=handlers, **kwargs)) return function return decorator def _copy_content(content_object): """Make a copy of the given content object. The content within ``content_object`` is iterated and saved. This is useful when the source of the content is volatile, a log file in a temporary directory for example. :param content_object: A `content.Content` instance. :return: A `content.Content` instance with the same mime-type as ``content_object`` and a non-volatile copy of its content. """ content_bytes = list(content_object.iter_bytes()) content_callback = lambda: content_bytes return content.Content(content_object.content_type, content_callback) def gather_details(source_dict, target_dict): """Merge the details from ``source_dict`` into ``target_dict``. :param source_dict: A dictionary of details will be gathered. :param target_dict: A dictionary into which details will be gathered. """ for name, content_object in source_dict.items(): new_name = name disambiguator = itertools.count(1) while new_name in target_dict: new_name = '%s-%d' % (name, advance_iterator(disambiguator)) name = new_name target_dict[name] = _copy_content(content_object) class TestCase(unittest.TestCase): """Extensions to the basic TestCase. :ivar exception_handlers: Exceptions to catch from setUp, runTest and tearDown. This list is able to be modified at any time and consists of (exception_class, handler(case, result, exception_value)) pairs. :cvar run_tests_with: A factory to make the ``RunTest`` to run tests with. Defaults to ``RunTest``. The factory is expected to take a test case and an optional list of exception handlers. """ skipException = TestSkipped run_tests_with = RunTest def __init__(self, *args, **kwargs): """Construct a TestCase. :param testMethod: The name of the method to run. :keyword runTest: Optional class to use to execute the test. If not supplied ``RunTest`` is used. The instance to be used is created when run() is invoked, so will be fresh each time. Overrides ``TestCase.run_tests_with`` if given. """ runTest = kwargs.pop('runTest', None) super(TestCase, self).__init__(*args, **kwargs) self._cleanups = [] self._unique_id_gen = itertools.count(1) # Generators to ensure unique traceback ids. Maps traceback label to # iterators. self._traceback_id_gens = {} self.__setup_called = False self.__teardown_called = False # __details is lazy-initialized so that a constructed-but-not-run # TestCase is safe to use with clone_test_with_new_id. self.__details = None test_method = self._get_test_method() if runTest is None: runTest = getattr( test_method, '_run_test_with', self.run_tests_with) self.__RunTest = runTest self.__exception_handlers = [] self.exception_handlers = [ (self.skipException, self._report_skip), (self.failureException, self._report_failure), (_ExpectedFailure, self._report_expected_failure), (_UnexpectedSuccess, self._report_unexpected_success), (Exception, self._report_error), ] if sys.version_info < (2, 6): # Catch old-style string exceptions with None as the instance self.exception_handlers.append((type(None), self._report_error)) def __eq__(self, other): eq = getattr(unittest.TestCase, '__eq__', None) if eq is not None and not unittest.TestCase.__eq__(self, other): return False return self.__dict__ == other.__dict__ def __repr__(self): # We add id to the repr because it makes testing testtools easier. return "<%s id=0x%0x>" % (self.id(), id(self)) def addDetail(self, name, content_object): """Add a detail to be reported with this test's outcome. For more details see pydoc testtools.TestResult. :param name: The name to give this detail. :param content_object: The content object for this detail. See testtools.content for more detail. """ if self.__details is None: self.__details = {} self.__details[name] = content_object def getDetails(self): """Get the details dict that will be reported with this test's outcome. For more details see pydoc testtools.TestResult. """ if self.__details is None: self.__details = {} return self.__details def patch(self, obj, attribute, value): """Monkey-patch 'obj.attribute' to 'value' while the test is running. If 'obj' has no attribute, then the monkey-patch will still go ahead, and the attribute will be deleted instead of restored to its original value. :param obj: The object to patch. Can be anything. :param attribute: The attribute on 'obj' to patch. :param value: The value to set 'obj.attribute' to. """ self.addCleanup(patch(obj, attribute, value)) def shortDescription(self): return self.id() def skipTest(self, reason): """Cause this test to be skipped. This raises self.skipException(reason). skipException is raised to permit a skip to be triggered at any point (during setUp or the testMethod itself). The run() method catches skipException and translates that into a call to the result objects addSkip method. :param reason: The reason why the test is being skipped. This must support being cast into a unicode string for reporting. """ raise self.skipException(reason) # skipTest is how python2.7 spells this. Sometime in the future # This should be given a deprecation decorator - RBC 20100611. skip = skipTest def _formatTypes(self, classOrIterable): """Format a class or a bunch of classes for display in an error.""" className = getattr(classOrIterable, '__name__', None) if className is None: className = ', '.join(klass.__name__ for klass in classOrIterable) return className def addCleanup(self, function, *arguments, **keywordArguments): """Add a cleanup function to be called after tearDown. Functions added with addCleanup will be called in reverse order of adding after tearDown, or after setUp if setUp raises an exception. If a function added with addCleanup raises an exception, the error will be recorded as a test error, and the next cleanup will then be run. Cleanup functions are always called before a test finishes running, even if setUp is aborted by an exception. """ self._cleanups.append((function, arguments, keywordArguments)) def addOnException(self, handler): """Add a handler to be called when an exception occurs in test code. This handler cannot affect what result methods are called, and is called before any outcome is called on the result object. An example use for it is to add some diagnostic state to the test details dict which is expensive to calculate and not interesting for reporting in the success case. Handlers are called before the outcome (such as addFailure) that the exception has caused. Handlers are called in first-added, first-called order, and if they raise an exception, that will propogate out of the test running machinery, halting test processing. As a result, do not call code that may unreasonably fail. """ self.__exception_handlers.append(handler) def _add_reason(self, reason): self.addDetail('reason', content.text_content(reason)) def assertEqual(self, expected, observed, message=''): """Assert that 'expected' is equal to 'observed'. :param expected: The expected value. :param observed: The observed value. :param message: An optional message to include in the error. """ matcher = Equals(expected) self.assertThat(observed, matcher, message) failUnlessEqual = assertEquals = assertEqual def assertIn(self, needle, haystack): """Assert that needle is in haystack.""" self.assertThat(haystack, Contains(needle)) def assertIsNone(self, observed, message=''): """Assert that 'observed' is equal to None. :param observed: The observed value. :param message: An optional message describing the error. """ matcher = Is(None) self.assertThat(observed, matcher, message) def assertIsNotNone(self, observed, message=''): """Assert that 'observed' is not equal to None. :param observed: The observed value. :param message: An optional message describing the error. """ matcher = Not(Is(None)) self.assertThat(observed, matcher, message) def assertIs(self, expected, observed, message=''): """Assert that 'expected' is 'observed'. :param expected: The expected value. :param observed: The observed value. :param message: An optional message describing the error. """ matcher = Is(expected) self.assertThat(observed, matcher, message) def assertIsNot(self, expected, observed, message=''): """Assert that 'expected' is not 'observed'.""" matcher = Not(Is(expected)) self.assertThat(observed, matcher, message) def assertNotIn(self, needle, haystack): """Assert that needle is not in haystack.""" matcher = Not(Contains(needle)) self.assertThat(haystack, matcher) def assertIsInstance(self, obj, klass, msg=None): if isinstance(klass, tuple): matcher = IsInstance(*klass) else: matcher = IsInstance(klass) self.assertThat(obj, matcher, msg) def assertRaises(self, excClass, callableObj, *args, **kwargs): """Fail unless an exception of class excClass is thrown by callableObj when invoked with arguments args and keyword arguments kwargs. If a different type of exception is thrown, it will not be caught, and the test case will be deemed to have suffered an error, exactly as for an unexpected exception. """ class ReRaiseOtherTypes(object): def match(self, matchee): if not issubclass(matchee[0], excClass): reraise(*matchee) class CaptureMatchee(object): def match(self, matchee): self.matchee = matchee[1] capture = CaptureMatchee() matcher = Raises(MatchesAll(ReRaiseOtherTypes(), MatchesException(excClass), capture)) our_callable = Nullary(callableObj, *args, **kwargs) self.assertThat(our_callable, matcher) return capture.matchee failUnlessRaises = assertRaises def assertThat(self, matchee, matcher, message='', verbose=False): """Assert that matchee is matched by matcher. :param matchee: An object to match with matcher. :param matcher: An object meeting the testtools.Matcher protocol. :raises MismatchError: When matcher does not match thing. """ matcher = Annotate.if_message(message, matcher) mismatch = matcher.match(matchee) if not mismatch: return existing_details = self.getDetails() for (name, content) in mismatch.get_details().items(): full_name = name suffix = 1 while full_name in existing_details: full_name = "%s-%d" % (name, suffix) suffix += 1 self.addDetail(full_name, content) raise MismatchError(matchee, matcher, mismatch, verbose) def defaultTestResult(self): return TestResult() def expectFailure(self, reason, predicate, *args, **kwargs): """Check that a test fails in a particular way. If the test fails in the expected way, a KnownFailure is caused. If it succeeds an UnexpectedSuccess is caused. The expected use of expectFailure is as a barrier at the point in a test where the test would fail. For example: >>> def test_foo(self): >>> self.expectFailure("1 should be 0", self.assertNotEqual, 1, 0) >>> self.assertEqual(1, 0) If in the future 1 were to equal 0, the expectFailure call can simply be removed. This separation preserves the original intent of the test while it is in the expectFailure mode. """ # TODO: implement with matchers. self._add_reason(reason) try: predicate(*args, **kwargs) except self.failureException: # GZ 2010-08-12: Don't know how to avoid exc_info cycle as the new # unittest _ExpectedFailure wants old traceback exc_info = sys.exc_info() try: self._report_traceback(exc_info) raise _ExpectedFailure(exc_info) finally: del exc_info else: raise _UnexpectedSuccess(reason) def getUniqueInteger(self): """Get an integer unique to this test. Returns an integer that is guaranteed to be unique to this instance. Use this when you need an arbitrary integer in your test, or as a helper for custom anonymous factory methods. """ return advance_iterator(self._unique_id_gen) def getUniqueString(self, prefix=None): """Get a string unique to this test. Returns a string that is guaranteed to be unique to this instance. Use this when you need an arbitrary string in your test, or as a helper for custom anonymous factory methods. :param prefix: The prefix of the string. If not provided, defaults to the id of the tests. :return: A bytestring of '-'. """ if prefix is None: prefix = self.id() return '%s-%d' % (prefix, self.getUniqueInteger()) def onException(self, exc_info, tb_label='traceback'): """Called when an exception propogates from test code. :seealso addOnException: """ if exc_info[0] not in [ TestSkipped, _UnexpectedSuccess, _ExpectedFailure]: self._report_traceback(exc_info, tb_label=tb_label) for handler in self.__exception_handlers: handler(exc_info) @staticmethod def _report_error(self, result, err): result.addError(self, details=self.getDetails()) @staticmethod def _report_expected_failure(self, result, err): result.addExpectedFailure(self, details=self.getDetails()) @staticmethod def _report_failure(self, result, err): result.addFailure(self, details=self.getDetails()) @staticmethod def _report_skip(self, result, err): if err.args: reason = err.args[0] else: reason = "no reason given." self._add_reason(reason) result.addSkip(self, details=self.getDetails()) def _report_traceback(self, exc_info, tb_label='traceback'): id_gen = self._traceback_id_gens.setdefault( tb_label, itertools.count(0)) tb_id = advance_iterator(id_gen) if tb_id: tb_label = '%s-%d' % (tb_label, tb_id) self.addDetail(tb_label, content.TracebackContent(exc_info, self)) @staticmethod def _report_unexpected_success(self, result, err): result.addUnexpectedSuccess(self, details=self.getDetails()) def run(self, result=None): return self.__RunTest(self, self.exception_handlers).run(result) def _run_setup(self, result): """Run the setUp function for this test. :param result: A testtools.TestResult to report activity to. :raises ValueError: If the base class setUp is not called, a ValueError is raised. """ ret = self.setUp() if not self.__setup_called: raise ValueError( "TestCase.setUp was not called. Have you upcalled all the " "way up the hierarchy from your setUp? e.g. Call " "super(%s, self).setUp() from your setUp()." % self.__class__.__name__) return ret def _run_teardown(self, result): """Run the tearDown function for this test. :param result: A testtools.TestResult to report activity to. :raises ValueError: If the base class tearDown is not called, a ValueError is raised. """ ret = self.tearDown() if not self.__teardown_called: raise ValueError( "TestCase.tearDown was not called. Have you upcalled all the " "way up the hierarchy from your tearDown? e.g. Call " "super(%s, self).tearDown() from your tearDown()." % self.__class__.__name__) return ret def _get_test_method(self): absent_attr = object() # Python 2.5+ method_name = getattr(self, '_testMethodName', absent_attr) if method_name is absent_attr: # Python 2.4 method_name = getattr(self, '_TestCase__testMethodName') return getattr(self, method_name) def _run_test_method(self, result): """Run the test method for this test. :param result: A testtools.TestResult to report activity to. :return: None. """ return self._get_test_method()() def useFixture(self, fixture): """Use fixture in a test case. The fixture will be setUp, and self.addCleanup(fixture.cleanUp) called. :param fixture: The fixture to use. :return: The fixture, after setting it up and scheduling a cleanup for it. """ try: fixture.setUp() except: gather_details(fixture.getDetails(), self.getDetails()) raise else: self.addCleanup(fixture.cleanUp) self.addCleanup( gather_details, fixture.getDetails(), self.getDetails()) return fixture def setUp(self): super(TestCase, self).setUp() self.__setup_called = True def tearDown(self): super(TestCase, self).tearDown() unittest.TestCase.tearDown(self) self.__teardown_called = True class PlaceHolder(object): """A placeholder test. `PlaceHolder` implements much of the same interface as TestCase and is particularly suitable for being added to TestResults. """ failureException = None def __init__(self, test_id, short_description=None, details=None, outcome='addSuccess', error=None): """Construct a `PlaceHolder`. :param test_id: The id of the placeholder test. :param short_description: The short description of the place holder test. If not provided, the id will be used instead. :param details: Outcome details as accepted by addSuccess etc. :param outcome: The outcome to call. Defaults to 'addSuccess'. """ self._test_id = test_id self._short_description = short_description self._details = details or {} self._outcome = outcome if error is not None: self._details['traceback'] = content.TracebackContent(error, self) def __call__(self, result=None): return self.run(result=result) def __repr__(self): internal = [self._outcome, self._test_id, self._details] if self._short_description is not None: internal.append(self._short_description) return "<%s.%s(%s)>" % ( self.__class__.__module__, self.__class__.__name__, ", ".join(map(repr, internal))) def __str__(self): return self.id() def countTestCases(self): return 1 def debug(self): pass def id(self): return self._test_id def _result(self, result): if result is None: return TestResult() else: return ExtendedToOriginalDecorator(result) def run(self, result=None): result = self._result(result) result.startTest(self) outcome = getattr(result, self._outcome) outcome(self, details=self._details) result.stopTest(self) def shortDescription(self): if self._short_description is None: return self.id() else: return self._short_description def ErrorHolder(test_id, error, short_description=None, details=None): """Construct an `ErrorHolder`. :param test_id: The id of the test. :param error: The exc info tuple that will be used as the test's error. This is inserted into the details as 'traceback' - any existing key will be overridden. :param short_description: An optional short description of the test. :param details: Outcome details as accepted by addSuccess etc. """ return PlaceHolder(test_id, short_description=short_description, details=details, outcome='addError', error=error) # Python 2.4 did not know how to copy functions. if types.FunctionType not in copy._copy_dispatch: copy._copy_dispatch[types.FunctionType] = copy._copy_immutable def clone_test_with_new_id(test, new_id): """Copy a `TestCase`, and give the copied test a new id. This is only expected to be used on tests that have been constructed but not executed. """ newTest = copy.copy(test) newTest.id = lambda: new_id return newTest def skip(reason): """A decorator to skip unit tests. This is just syntactic sugar so users don't have to change any of their unit tests in order to migrate to python 2.7, which provides the @unittest.skip decorator. """ def decorator(test_item): if wraps is not None: @wraps(test_item) def skip_wrapper(*args, **kwargs): raise TestCase.skipException(reason) else: def skip_wrapper(test_item): test_item.skip(reason) return skip_wrapper return decorator def skipIf(condition, reason): """Skip a test if the condition is true.""" if condition: return skip(reason) def _id(obj): return obj return _id def skipUnless(condition, reason): """Skip a test unless the condition is true.""" if not condition: return skip(reason) def _id(obj): return obj return _id class ExpectedException: """A context manager to handle expected exceptions. In Python 2.5 or later:: def test_foo(self): with ExpectedException(ValueError, 'fo.*'): raise ValueError('foo') will pass. If the raised exception has a type other than the specified type, it will be re-raised. If it has a 'str()' that does not match the given regular expression, an AssertionError will be raised. If no exception is raised, an AssertionError will be raised. """ def __init__(self, exc_type, value_re=None): """Construct an `ExpectedException`. :param exc_type: The type of exception to expect. :param value_re: A regular expression to match against the 'str()' of the raised exception. """ self.exc_type = exc_type self.value_re = value_re def __enter__(self): pass def __exit__(self, exc_type, exc_value, traceback): if exc_type is None: raise AssertionError('%s not raised.' % self.exc_type.__name__) if exc_type != self.exc_type: return False if self.value_re: matcher = MatchesException(self.exc_type, self.value_re) mismatch = matcher.match((exc_type, exc_value, traceback)) if mismatch: raise AssertionError(mismatch.describe()) return True class Nullary(object): """Turn a callable into a nullary callable. The advantage of this over ``lambda: f(*args, **kwargs)`` is that it preserves the ``repr()`` of ``f``. """ def __init__(self, callable_object, *args, **kwargs): self._callable_object = callable_object self._args = args self._kwargs = kwargs def __call__(self): return self._callable_object(*self._args, **self._kwargs) def __repr__(self): return repr(self._callable_object) # Signal that this is part of the testing framework, and that code from this # should not normally appear in tracebacks. __unittest = True