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# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Test cases for Twisted component architecture.
"""
from __future__ import division, absolute_import
from functools import wraps
from zope.interface import Interface, implementer, Attribute
from zope.interface.adapter import AdapterRegistry
from twisted.python.compat import comparable, cmp
from twisted.trial import unittest
from twisted.python import components
from twisted.python.components import _addHook, _removeHook, proxyForInterface
class Compo(components.Componentized):
num = 0
def inc(self):
self.num = self.num + 1
return self.num
class IAdept(Interface):
def adaptorFunc():
raise NotImplementedError()
class IElapsed(Interface):
def elapsedFunc():
"""
1!
"""
@implementer(IAdept)
class Adept(components.Adapter):
def __init__(self, orig):
self.original = orig
self.num = 0
def adaptorFunc(self):
self.num = self.num + 1
return self.num, self.original.inc()
@implementer(IElapsed)
class Elapsed(components.Adapter):
def elapsedFunc(self):
return 1
class AComp(components.Componentized):
pass
class BComp(AComp):
pass
class CComp(BComp):
pass
class ITest(Interface):
pass
class ITest2(Interface):
pass
class ITest3(Interface):
pass
class ITest4(Interface):
pass
@implementer(ITest, ITest3, ITest4)
class Test(components.Adapter):
def __init__(self, orig):
pass
@implementer(ITest2)
class Test2:
temporaryAdapter = 1
def __init__(self, orig):
pass
class RegistryUsingMixin(object):
"""
Mixin for test cases which modify the global registry somehow.
"""
def setUp(self):
"""
Configure L{twisted.python.components.registerAdapter} to mutate an
alternate registry to improve test isolation.
"""
# Create a brand new, empty registry and put it onto the components
# module where registerAdapter will use it. Also ensure that it goes
# away at the end of the test.
scratchRegistry = AdapterRegistry()
self.patch(components, 'globalRegistry', scratchRegistry)
# Hook the new registry up to the adapter lookup system and ensure that
# association is also discarded after the test.
hook = _addHook(scratchRegistry)
self.addCleanup(_removeHook, hook)
class ComponentizedTests(unittest.SynchronousTestCase, RegistryUsingMixin):
"""
Simple test case for caching in Componentized.
"""
def setUp(self):
RegistryUsingMixin.setUp(self)
components.registerAdapter(Test, AComp, ITest)
components.registerAdapter(Test, AComp, ITest3)
components.registerAdapter(Test2, AComp, ITest2)
def testComponentized(self):
components.registerAdapter(Adept, Compo, IAdept)
components.registerAdapter(Elapsed, Compo, IElapsed)
c = Compo()
assert c.getComponent(IAdept).adaptorFunc() == (1, 1)
assert c.getComponent(IAdept).adaptorFunc() == (2, 2)
assert IElapsed(IAdept(c)).elapsedFunc() == 1
def testInheritanceAdaptation(self):
c = CComp()
co1 = c.getComponent(ITest)
co2 = c.getComponent(ITest)
co3 = c.getComponent(ITest2)
co4 = c.getComponent(ITest2)
assert co1 is co2
assert co3 is not co4
c.removeComponent(co1)
co5 = c.getComponent(ITest)
co6 = c.getComponent(ITest)
assert co5 is co6
assert co1 is not co5
def testMultiAdapter(self):
c = CComp()
co1 = c.getComponent(ITest)
co3 = c.getComponent(ITest3)
co4 = c.getComponent(ITest4)
self.assertIdentical(None, co4)
self.assertIdentical(co1, co3)
def test_getComponentDefaults(self):
"""
Test that a default value specified to Componentized.getComponent if
there is no component for the requested interface.
"""
componentized = components.Componentized()
default = object()
self.assertIdentical(
componentized.getComponent(ITest, default),
default)
self.assertIdentical(
componentized.getComponent(ITest, default=default),
default)
self.assertIdentical(
componentized.getComponent(ITest),
None)
def test_setAdapter(self):
"""
C{Componentized.setAdapter} sets a component for an interface by
wrapping the instance with the given adapter class.
"""
componentized = components.Componentized()
componentized.setAdapter(IAdept, Adept)
component = componentized.getComponent(IAdept)
self.assertEqual(component.original, componentized)
self.assertIsInstance(component, Adept)
def test_addAdapter(self):
"""
C{Componentized.setAdapter} adapts the instance by wrapping it with
given adapter class, then stores it using C{addComponent}.
"""
componentized = components.Componentized()
componentized.addAdapter(Adept, ignoreClass=True)
component = componentized.getComponent(IAdept)
self.assertEqual(component.original, componentized)
self.assertIsInstance(component, Adept)
def test_setComponent(self):
"""
C{Componentized.setComponent} stores the given component using the
given interface as the key.
"""
componentized = components.Componentized()
obj = object()
componentized.setComponent(ITest, obj)
self.assertIdentical(componentized.getComponent(ITest), obj)
def test_unsetComponent(self):
"""
C{Componentized.setComponent} removes the cached component for the
given interface.
"""
componentized = components.Componentized()
obj = object()
componentized.setComponent(ITest, obj)
componentized.unsetComponent(ITest)
self.assertIdentical(componentized.getComponent(ITest), None)
def test_reprableComponentized(self):
"""
C{ReprableComponentized} has a C{__repr__} that lists its cache.
"""
rc = components.ReprableComponentized()
rc.setComponent(ITest, "hello")
result = repr(rc)
self.assertIn("ITest", result)
self.assertIn("hello", result)
class AdapterTests(unittest.SynchronousTestCase):
"""Test adapters."""
def testAdapterGetComponent(self):
o = object()
a = Adept(o)
self.assertRaises(components.CannotAdapt, ITest, a)
self.assertEqual(ITest(a, None), None)
class IMeta(Interface):
pass
@implementer(IMeta)
class MetaAdder(components.Adapter):
def add(self, num):
return self.original.num + num
@implementer(IMeta)
class BackwardsAdder(components.Adapter):
def add(self, num):
return self.original.num - num
class MetaNumber:
def __init__(self, num):
self.num = num
class FakeAdder:
def add(self, num):
return num + 5
class FakeNumber:
num = 3
class ComponentNumber(components.Componentized):
def __init__(self):
self.num = 0
components.Componentized.__init__(self)
implementer(IMeta)
class ComponentMeta(components.Adapter):
def __init__(self, original):
components.Adapter.__init__(self, original)
self.num = self.original.num
class ComponentAdder(ComponentMeta):
def add(self, num):
self.num += num
return self.num
class ComponentDoubler(ComponentMeta):
def add(self, num):
self.num += (num * 2)
return self.original.num
class IAttrX(Interface):
def x():
pass
class IAttrXX(Interface):
def xx():
pass
@implementer(IAttrX)
class Xcellent:
def x(self):
return 'x!'
@comparable
class DoubleXAdapter:
num = 42
def __init__(self, original):
self.original = original
def xx(self):
return (self.original.x(), self.original.x())
def __cmp__(self, other):
return cmp(self.num, other.num)
class MetaInterfaceTests(RegistryUsingMixin, unittest.SynchronousTestCase):
def testBasic(self):
components.registerAdapter(MetaAdder, MetaNumber, IMeta)
n = MetaNumber(1)
self.assertEqual(IMeta(n).add(1), 2)
def testComponentizedInteraction(self):
components.registerAdapter(ComponentAdder, ComponentNumber, IMeta)
c = ComponentNumber()
IMeta(c).add(1)
IMeta(c).add(1)
self.assertEqual(IMeta(c).add(1), 3)
def testAdapterWithCmp(self):
# Make sure that a __cmp__ on an adapter doesn't break anything
components.registerAdapter(DoubleXAdapter, IAttrX, IAttrXX)
xx = IAttrXX(Xcellent())
self.assertEqual(('x!', 'x!'), xx.xx())
class RegistrationTests(RegistryUsingMixin, unittest.SynchronousTestCase):
"""
Tests for adapter registration.
"""
def _registerAdapterForClassOrInterface(self, original):
"""
Register an adapter with L{components.registerAdapter} for the given
class or interface and verify that the adapter can be looked up with
L{components.getAdapterFactory}.
"""
adapter = lambda o: None
components.registerAdapter(adapter, original, ITest)
self.assertIdentical(
components.getAdapterFactory(original, ITest, None),
adapter)
def test_registerAdapterForClass(self):
"""
Test that an adapter from a class can be registered and then looked
up.
"""
class TheOriginal(object):
pass
return self._registerAdapterForClassOrInterface(TheOriginal)
def test_registerAdapterForInterface(self):
"""
Test that an adapter from an interface can be registered and then
looked up.
"""
return self._registerAdapterForClassOrInterface(ITest2)
def _duplicateAdapterForClassOrInterface(self, original):
"""
Verify that L{components.registerAdapter} raises L{ValueError} if the
from-type/interface and to-interface pair is not unique.
"""
firstAdapter = lambda o: False
secondAdapter = lambda o: True
components.registerAdapter(firstAdapter, original, ITest)
self.assertRaises(
ValueError,
components.registerAdapter,
secondAdapter, original, ITest)
# Make sure that the original adapter is still around as well
self.assertIdentical(
components.getAdapterFactory(original, ITest, None),
firstAdapter)
def test_duplicateAdapterForClass(self):
"""
Test that attempting to register a second adapter from a class
raises the appropriate exception.
"""
class TheOriginal(object):
pass
return self._duplicateAdapterForClassOrInterface(TheOriginal)
def test_duplicateAdapterForInterface(self):
"""
Test that attempting to register a second adapter from an interface
raises the appropriate exception.
"""
return self._duplicateAdapterForClassOrInterface(ITest2)
def _duplicateAdapterForClassOrInterfaceAllowed(self, original):
"""
Verify that when C{components.ALLOW_DUPLICATES} is set to C{True}, new
adapter registrations for a particular from-type/interface and
to-interface pair replace older registrations.
"""
firstAdapter = lambda o: False
secondAdapter = lambda o: True
class TheInterface(Interface):
pass
components.registerAdapter(firstAdapter, original, TheInterface)
components.ALLOW_DUPLICATES = True
try:
components.registerAdapter(secondAdapter, original, TheInterface)
self.assertIdentical(
components.getAdapterFactory(original, TheInterface, None),
secondAdapter)
finally:
components.ALLOW_DUPLICATES = False
# It should be rejected again at this point
self.assertRaises(
ValueError,
components.registerAdapter,
firstAdapter, original, TheInterface)
self.assertIdentical(
components.getAdapterFactory(original, TheInterface, None),
secondAdapter)
def test_duplicateAdapterForClassAllowed(self):
"""
Test that when L{components.ALLOW_DUPLICATES} is set to a true
value, duplicate registrations from classes are allowed to override
the original registration.
"""
class TheOriginal(object):
pass
return self._duplicateAdapterForClassOrInterfaceAllowed(TheOriginal)
def test_duplicateAdapterForInterfaceAllowed(self):
"""
Test that when L{components.ALLOW_DUPLICATES} is set to a true
value, duplicate registrations from interfaces are allowed to
override the original registration.
"""
class TheOriginal(Interface):
pass
return self._duplicateAdapterForClassOrInterfaceAllowed(TheOriginal)
def _multipleInterfacesForClassOrInterface(self, original):
"""
Verify that an adapter can be registered for multiple to-interfaces at a
time.
"""
adapter = lambda o: None
components.registerAdapter(adapter, original, ITest, ITest2)
self.assertIdentical(
components.getAdapterFactory(original, ITest, None), adapter)
self.assertIdentical(
components.getAdapterFactory(original, ITest2, None), adapter)
def test_multipleInterfacesForClass(self):
"""
Test the registration of an adapter from a class to several
interfaces at once.
"""
class TheOriginal(object):
pass
return self._multipleInterfacesForClassOrInterface(TheOriginal)
def test_multipleInterfacesForInterface(self):
"""
Test the registration of an adapter from an interface to several
interfaces at once.
"""
return self._multipleInterfacesForClassOrInterface(ITest3)
def _subclassAdapterRegistrationForClassOrInterface(self, original):
"""
Verify that a new adapter can be registered for a particular
to-interface from a subclass of a type or interface which already has an
adapter registered to that interface and that the subclass adapter takes
precedence over the base class adapter.
"""
firstAdapter = lambda o: True
secondAdapter = lambda o: False
class TheSubclass(original):
pass
components.registerAdapter(firstAdapter, original, ITest)
components.registerAdapter(secondAdapter, TheSubclass, ITest)
self.assertIdentical(
components.getAdapterFactory(original, ITest, None),
firstAdapter)
self.assertIdentical(
components.getAdapterFactory(TheSubclass, ITest, None),
secondAdapter)
def test_subclassAdapterRegistrationForClass(self):
"""
Test that an adapter to a particular interface can be registered
from both a class and its subclass.
"""
class TheOriginal(object):
pass
return self._subclassAdapterRegistrationForClassOrInterface(TheOriginal)
def test_subclassAdapterRegistrationForInterface(self):
"""
Test that an adapter to a particular interface can be registered
from both an interface and its subclass.
"""
return self._subclassAdapterRegistrationForClassOrInterface(ITest2)
class IProxiedInterface(Interface):
"""
An interface class for use by L{proxyForInterface}.
"""
ifaceAttribute = Attribute("""
An example declared attribute, which should be proxied.""")
def yay(*a, **kw):
"""
A sample method which should be proxied.
"""
class IProxiedSubInterface(IProxiedInterface):
"""
An interface that derives from another for use with L{proxyForInterface}.
"""
def boo(self):
"""
A different sample method which should be proxied.
"""
@implementer(IProxiedInterface)
class Yayable(object):
"""
A provider of L{IProxiedInterface} which increments a counter for
every call to C{yay}.
@ivar yays: The number of times C{yay} has been called.
"""
def __init__(self):
self.yays = 0
self.yayArgs = []
def yay(self, *a, **kw):
"""
Increment C{self.yays}.
"""
self.yays += 1
self.yayArgs.append((a, kw))
return self.yays
@implementer(IProxiedSubInterface)
class Booable(object):
"""
An implementation of IProxiedSubInterface
"""
yayed = False
booed = False
def yay(self):
"""
Mark the fact that 'yay' has been called.
"""
self.yayed = True
def boo(self):
"""
Mark the fact that 'boo' has been called.1
"""
self.booed = True
class IMultipleMethods(Interface):
"""
An interface with multiple methods.
"""
def methodOne():
"""
The first method. Should return 1.
"""
def methodTwo():
"""
The second method. Should return 2.
"""
class MultipleMethodImplementor(object):
"""
A precise implementation of L{IMultipleMethods}.
"""
def methodOne(self):
"""
@return: 1
"""
return 1
def methodTwo(self):
"""
@return: 2
"""
return 2
class ProxyForInterfaceTests(unittest.SynchronousTestCase):
"""
Tests for L{proxyForInterface}.
"""
def test_original(self):
"""
Proxy objects should have an C{original} attribute which refers to the
original object passed to the constructor.
"""
original = object()
proxy = proxyForInterface(IProxiedInterface)(original)
self.assertIdentical(proxy.original, original)
def test_proxyMethod(self):
"""
The class created from L{proxyForInterface} passes methods on an
interface to the object which is passed to its constructor.
"""
klass = proxyForInterface(IProxiedInterface)
yayable = Yayable()
proxy = klass(yayable)
proxy.yay()
self.assertEqual(proxy.yay(), 2)
self.assertEqual(yayable.yays, 2)
def test_decoratedProxyMethod(self):
"""
Methods of the class created from L{proxyForInterface} can be used with
the decorator-helper L{functools.wraps}.
"""
base = proxyForInterface(IProxiedInterface)
class klass(base):
@wraps(base.yay)
def yay(self):
self.original.yays += 1
return base.yay(self)
original = Yayable()
yayable = klass(original)
yayable.yay()
self.assertEqual(2, original.yays)
def test_proxyAttribute(self):
"""
Proxy objects should proxy declared attributes, but not other
attributes.
"""
yayable = Yayable()
yayable.ifaceAttribute = object()
proxy = proxyForInterface(IProxiedInterface)(yayable)
self.assertIdentical(proxy.ifaceAttribute, yayable.ifaceAttribute)
self.assertRaises(AttributeError, lambda: proxy.yays)
def test_proxySetAttribute(self):
"""
The attributes that proxy objects proxy should be assignable and affect
the original object.
"""
yayable = Yayable()
proxy = proxyForInterface(IProxiedInterface)(yayable)
thingy = object()
proxy.ifaceAttribute = thingy
self.assertIdentical(yayable.ifaceAttribute, thingy)
def test_proxyDeleteAttribute(self):
"""
The attributes that proxy objects proxy should be deletable and affect
the original object.
"""
yayable = Yayable()
yayable.ifaceAttribute = None
proxy = proxyForInterface(IProxiedInterface)(yayable)
del proxy.ifaceAttribute
self.assertFalse(hasattr(yayable, 'ifaceAttribute'))
def test_multipleMethods(self):
"""
[Regression test] The proxy should send its method calls to the correct
method, not the incorrect one.
"""
multi = MultipleMethodImplementor()
proxy = proxyForInterface(IMultipleMethods)(multi)
self.assertEqual(proxy.methodOne(), 1)
self.assertEqual(proxy.methodTwo(), 2)
def test_subclassing(self):
"""
It is possible to subclass the result of L{proxyForInterface}.
"""
class SpecializedProxy(proxyForInterface(IProxiedInterface)):
"""
A specialized proxy which can decrement the number of yays.
"""
def boo(self):
"""
Decrement the number of yays.
"""
self.original.yays -= 1
yayable = Yayable()
special = SpecializedProxy(yayable)
self.assertEqual(yayable.yays, 0)
special.boo()
self.assertEqual(yayable.yays, -1)
def test_proxyName(self):
"""
The name of a proxy class indicates which interface it proxies.
"""
proxy = proxyForInterface(IProxiedInterface)
self.assertEqual(
proxy.__name__,
"(Proxy for "
"twisted.python.test.test_components.IProxiedInterface)")
def test_implements(self):
"""
The resulting proxy implements the interface that it proxies.
"""
proxy = proxyForInterface(IProxiedInterface)
self.assertTrue(IProxiedInterface.implementedBy(proxy))
def test_proxyDescriptorGet(self):
"""
_ProxyDescriptor's __get__ method should return the appropriate
attribute of its argument's 'original' attribute if it is invoked with
an object. If it is invoked with None, it should return a false
class-method emulator instead.
For some reason, Python's documentation recommends to define
descriptors' __get__ methods with the 'type' parameter as optional,
despite the fact that Python itself never actually calls the descriptor
that way. This is probably do to support 'foo.__get__(bar)' as an
idiom. Let's make sure that the behavior is correct. Since we don't
actually use the 'type' argument at all, this test calls it the
idiomatic way to ensure that signature works; test_proxyInheritance
verifies the how-Python-actually-calls-it signature.
"""
class Sample:
called = False
def hello(self):
self.called = True
fakeProxy = Sample()
testObject = Sample()
fakeProxy.original = testObject
pd = components._ProxyDescriptor("hello", "original")
self.assertEqual(pd.__get__(fakeProxy), testObject.hello)
fakeClassMethod = pd.__get__(None)
fakeClassMethod(fakeProxy)
self.assertTrue(testObject.called)
def test_proxyInheritance(self):
"""
Subclasses of the class returned from L{proxyForInterface} should be
able to upcall methods by reference to their superclass, as any normal
Python class can.
"""
class YayableWrapper(proxyForInterface(IProxiedInterface)):
"""
This class does not override any functionality.
"""
class EnhancedWrapper(YayableWrapper):
"""
This class overrides the 'yay' method.
"""
wrappedYays = 1
def yay(self, *a, **k):
self.wrappedYays += 1
return YayableWrapper.yay(self, *a, **k) + 7
yayable = Yayable()
wrapper = EnhancedWrapper(yayable)
self.assertEqual(wrapper.yay(3, 4, x=5, y=6), 8)
self.assertEqual(yayable.yayArgs,
[((3, 4), dict(x=5, y=6))])
def test_interfaceInheritance(self):
"""
Proxies of subinterfaces generated with proxyForInterface should allow
access to attributes of both the child and the base interfaces.
"""
proxyClass = proxyForInterface(IProxiedSubInterface)
booable = Booable()
proxy = proxyClass(booable)
proxy.yay()
proxy.boo()
self.assertTrue(booable.yayed)
self.assertTrue(booable.booed)
def test_attributeCustomization(self):
"""
The original attribute name can be customized via the
C{originalAttribute} argument of L{proxyForInterface}: the attribute
should change, but the methods of the original object should still be
callable, and the attributes still accessible.
"""
yayable = Yayable()
yayable.ifaceAttribute = object()
proxy = proxyForInterface(
IProxiedInterface, originalAttribute='foo')(yayable)
self.assertIdentical(proxy.foo, yayable)
# Check the behavior
self.assertEqual(proxy.yay(), 1)
self.assertIdentical(proxy.ifaceAttribute, yayable.ifaceAttribute)
thingy = object()
proxy.ifaceAttribute = thingy
self.assertIdentical(yayable.ifaceAttribute, thingy)
del proxy.ifaceAttribute
self.assertFalse(hasattr(yayable, 'ifaceAttribute'))
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