nti.testing 4.1.0

基本匹配器

is_true 和 is_false 检查提供的对象（出于解释目的，我们使用字面量，但显然当匹配的对象是一个变量时（通常是一个更复杂类型的变量）更有意义，并且读起来更好）的布尔值。

>>> from hamcrest import assert_that, is_
>>> from nti.testing import is_true, is_false
>>> assert_that("Hi", is_true())
>>> assert_that(0, is_false())

接口匹配器

接下来是支持基本使用 zope.interface 的匹配器。

我们可以检查一个对象是否提供了一个接口，以及一个工厂是否实现了它。

>>> from zope.interface import Interface, Attribute, implementer
>>> class IThing1(Interface):
...     pass
>>> class IThing2(Interface):
...     pass
>>> class IThings(IThing1, IThing2):
...     got_that_thing_i_sent_you = Attribute("Did you get that thing?")
>>> @implementer(IThings)
... class Thing(object):
...     def __repr__(self): return "<object Thing>"

>>> from nti.testing import provides, implements
>>> assert_that(Thing(), provides(IThings))
>>> assert_that(Thing, implements(IThings))

细心的读者会注意到，IThings 定义了一个我们的实现实际上并不提供的属性。这就是下一个更严格的检查出现的地方。 verifiably_provides 使用接口机制来确定接口中指定的所有属性和方法都存在并按描述提供。

>>> from nti.testing import verifiably_provides
>>> assert_that(Thing(), verifiably_provides(IThing2, IThing1))
>>> assert_that(Thing(), verifiably_provides(IThings))
Traceback (most recent call last):
...
AssertionError:...
Expected: object verifiably providing <...IThings>
     but: Using class <class 'Thing'> the object <object Thing> has failed to implement interface ....IThings: The ....IThings.got_that_thing_i_sent_you attribute was not provided.
<BLANKLINE>

如果多个属性或方法未提供，所有此类缺失信息都将被报告。

>>> class IThingReceiver(IThings):
...    def receive(some_thing):
...        """Get the thing"""
>>> @implementer(IThingReceiver)
... class ThingReceiver(object):
...     def __repr__(self): return "<object ThingReceiver>"
>>> assert_that(ThingReceiver(), verifiably_provides(IThingReceiver))
Traceback (most recent call last):
...
AssertionError:...
Expected: object verifiably providing <...IThingReceiver>
     but: Using class <class 'ThingReceiver'> the object <object ThingReceiver> has failed to implement interface ....IThingReceiver:
          The ....IThings.got_that_thing_i_sent_you attribute was not provided
          The ....IThingReceiver.receive(some_thing) attribute was not provided
<BLANKLINE>

zope.interface 只能检查属性或方法是否存在。为了在属性值上放置（任意）更严格的约束，我们可以升级到 zope.schema 和 validly_provides 匹配器。

>>> from zope.schema import Bool
>>> class IBoolThings(IThing1, IThing2):
...     got_that_thing_i_sent_you = Bool(required=True)
>>> @implementer(IBoolThings)
... class BoolThing(object):
...     def __repr__(self): return "<object BoolThing>"

validly_provides 是 verifiably_provides 的超集。

>>> from nti.testing import validly_provides
>>> assert_that(BoolThing(), validly_provides(IThing1, IThing2))
>>> assert_that(BoolThing(), validly_provides(IBoolThings))
Traceback (most recent call last):
...
AssertionError:...
Expected: (object verifiably providing <...IBoolThings> and object validly providing ....IBoolThings)
     but: object verifiably providing <....IBoolThings> Using class <class 'BoolThing'> the object <object BoolThing> has failed to implement interface ....IBoolThings: The ....IBoolThings.got_that_thing_i_sent_you attribute was not provided.
<BLANKLINE>

为了更精细的控制，我们可以使用 validated_by 和 not_validated_by 将数据与模式字段进行比较。

>>> from nti.testing import validated_by, not_validated_by
>>> field = IBoolThings.get('got_that_thing_i_sent_you')
>>> assert_that(True, is_(validated_by(field)))
>>> assert_that(None, is_(not_validated_by(field)))

父子关系

aq_inContextOf 匹配器使用 Acquisition 的概念来检查父子关系。

>>> from nti.testing import aq_inContextOf
>>> class Parent(object):
...     pass
>>> class Child(object):
...     __parent__ = None
>>> parent = Parent()
>>> child = Child()
>>> child.__parent__ = parent

>>> assert_that(child, aq_inContextOf(parent))