View of /DecoratorTools/test_decorators.py

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Refactor tracing mechanism to be less intrusive; specifically, don't
install a global trace hook if one's already in place, don't uninstall
it if we didn't install it, and make sure that uninstallations happen
in the correct chaining order.  This may fix some long-standing issues
with debuggers (such as PyDev) that use different local and global 
tracing functions.

from unittest import TestCase, makeSuite, TestSuite
from peak.util.decorators import *
import sys

def ping(log, value):

    """Class decorator for testing"""

    def pong(klass):
        log.append((value,klass))
        return [klass]

    decorate_class(pong)


def additional_tests():
    import doctest
    return doctest.DocFileSuite(
        'README.txt',
        optionflags=doctest.ELLIPSIS|doctest.NORMALIZE_WHITESPACE,
    )




















class DecoratorTests(TestCase):

    def testAssignAdvice(self):

        log = []
        def track(f,k,v,d):
            log.append((f,k,v))
            if k in f.f_locals:
                del f.f_locals[k]   # simulate old-style advisor

        decorate_assignment(track,frame=sys._getframe())
        test_var = 1
        self.assertEqual(log, [(sys._getframe(),'test_var',1)])
        log = []
        decorate_assignment(track,1)
        test2 = 42
        self.assertEqual(log, [(sys._getframe(),'test2',42)])

        # Try doing double duty, redefining an existing variable...
        log = []
        decorate_assignment(track,1)
        decorate_assignment(track,1)

        test2 = 42
        self.assertEqual(log, [(sys._getframe(),'test2',42)]*2)


    def testAs(self):

        def f(): pass

        [decorate(lambda x: [x])]
        f1 = f

        self.assertEqual(f1, [f])

        [decorate(list, lambda x: (x,))]
        f1 = f
        self.assertEqual(f1, [f])


    def test24DecoratorMode(self):
        log = []
        def track(f,k,v,d):
            log.append((f,k,v))
            return v

        def foo(x): pass

        decorate_assignment(track,1)(foo)
        x = 1

        self.assertEqual(log, [(sys._getframe(),'foo',foo)])

    def testAlreadyTracing(self):
        log = []
        def my_global_tracer(frm,event,arg):
            log.append(frm.f_code.co_name)
            return my_local_tracer
        def my_local_tracer(*args):
            return my_local_tracer

        sys.settrace(my_global_tracer)  # This is going to break your debugger!
        self.testAssignAdvice()
        sys.settrace(None)

        # And this part is going to fail if testAssignAdvice() or
        # decorate_assignment change much...
        self.assertEqual(log, [
            'testAssignAdvice',
            'decorate_assignment', 'enclosing_frame', '<lambda>', 'failUnlessEqual',
            'decorate_assignment', 'enclosing_frame', '<lambda>', 'failUnlessEqual',
            'decorate_assignment', 'enclosing_frame', '<lambda>',
            'decorate_assignment', 'enclosing_frame', '<lambda>', 'failUnlessEqual',
        ])
            






moduleLevelFrameInfo = frameinfo(sys._getframe())

class FrameInfoTest(TestCase):

    classLevelFrameInfo = frameinfo(sys._getframe())

    def testModuleInfo(self):
        kind,module,f_locals,f_globals = moduleLevelFrameInfo
        assert kind=="module"
        for d in module.__dict__, f_locals, f_globals:
            assert d is globals()

    def testClassInfo(self):
        kind,module,f_locals,f_globals = self.classLevelFrameInfo
        assert kind=="class"
        assert f_locals['classLevelFrameInfo'] is self.classLevelFrameInfo
        for d in module.__dict__, f_globals:
            assert d is globals()


    def testCallInfo(self):
        kind,module,f_locals,f_globals = frameinfo(sys._getframe())
        assert kind=="function call"
        assert f_locals is locals() # ???
        for d in module.__dict__, f_globals:
            assert d is globals()


    def testClassExec(self):
        d = {'sys':sys, 'frameinfo':frameinfo}
        exec "class Foo: info=frameinfo(sys._getframe())" in d
        kind,module,f_locals,f_globals = d['Foo'].info
        assert kind=="class", kind








class ClassDecoratorTests(TestCase):

    def testOrder(self):
        log = []
        class Foo:
            ping(log, 1)
            ping(log, 2)
            ping(log, 3)

        # Strip the list nesting
        for i in 1,2,3:
            assert isinstance(Foo,list)
            Foo, = Foo

        assert log == [
            (1, Foo),
            (2, [Foo]),
            (3, [[Foo]]),
        ]

    def testOutside(self):
        try:
            ping([], 1)
        except SyntaxError:
            pass
        else:
            raise AssertionError(
                "Should have detected advice outside class body"
            )

    def testDoubleType(self):
        if sys.hexversion >= 0x02030000:
            return  # you can't duplicate bases in 2.3
        class aType(type,type):
            ping([],1)
        aType, = aType
        assert aType.__class__ is type




    def testSingleExplicitMeta(self):

        class M(type): pass

        class C(M):
            __metaclass__ = M
            ping([],1)

        C, = C
        assert C.__class__ is M


    def testMixedMetas(self):

        class M1(type): pass
        class M2(type): pass

        class B1: __metaclass__ = M1
        class B2: __metaclass__ = M2

        try:
            class C(B1,B2):
                ping([],1)
        except TypeError:
            pass
        else:
            raise AssertionError("Should have gotten incompatibility error")

        class M3(M1,M2): pass

        class C(B1,B2):
            __metaclass__ = M3
            ping([],1)

        assert isinstance(C,list)
        C, = C
        assert isinstance(C,M3)




    def testMetaOfClass(self):

        class metameta(type):
            pass

        class meta(type):
            __metaclass__ = metameta

        assert metaclass_for_bases((meta,type))==metameta



class ClassyMetaTests(TestCase):
    """Test subclass/instance checking of classy for Python 2.6+ ABC mixin"""

    def setUp(self):
        class x(classy): pass
        class y(x): pass
        class cc(type(classy)): pass
        self.__dict__.update(locals())

    def test_subclassing(self):
        self.failUnless(issubclass(self.x, classy))
        self.failUnless(issubclass(self.y, self.x))
        self.failIf(issubclass(self.x, self.y))
        self.failIf(issubclass(classy, self.x))
        self.failIf(issubclass(self.x, type(classy)))

    def test_instancing(self):
        self.failIf(isinstance(self.x, classy))
        self.failUnless(isinstance(self.x, type(classy)))
        self.failIf(isinstance(self.x(), type(classy)))
        self.failIf(isinstance(object, type(classy)))
        self.failIf(isinstance(self.x(),self.y))
        self.failUnless(isinstance(self.y(),self.x))