def testInvariant(self):
from zope.interface.exceptions import Invalid
from zope.interface import directlyProvides
from zope.interface.tests.unitfixtures import BarGreaterThanFoo
from zope.interface.tests.unitfixtures import ifFooThenBar
from zope.interface.tests.unitfixtures import IInvariant
from zope.interface.tests.unitfixtures import InvariantC
from zope.interface.tests.unitfixtures import ISubInvariant
# set up
o = InvariantC()
directlyProvides(o, IInvariant)
# a helper
def errorsEqual(self, o, error_len, error_msgs, iface=None):
if iface is None:
iface = IInvariant
self.assertRaises(Invalid, iface.validateInvariants, o)
e = []
try:
iface.validateInvariants(o, e)
except Invalid, error:
self.assertEquals(error.args[0], e)
else:
self.assertEquals(msg, error_msgs.pop(0))
# the tests
self.assertEquals(IInvariant.getTaggedValue('invariants'),
[ifFooThenBar])
self.assertEquals(IInvariant.validateInvariants(o), None)
o.bar = 27
self.assertEquals(IInvariant.validateInvariants(o), None)
o.foo = 42
self.assertEquals(IInvariant.validateInvariants(o), None)
del o.bar
errorsEqual(self, o, 1, ['If Foo, then Bar!'])
# nested interfaces with invariants:
self.assertEquals(ISubInvariant.getTaggedValue('invariants'),
[BarGreaterThanFoo])
o = InvariantC()
directlyProvides(o, ISubInvariant)
o.foo = 42
# even though the interface has changed, we should still only have one
# error.
errorsEqual(self, o, 1, ['If Foo, then Bar!'], ISubInvariant)
# however, if we set foo to 0 (Boolean False) and bar to a negative
# number then we'll get the new error
o.foo = 2
o.bar = 1
errorsEqual(self, o, 1, ['Please, Boo MUST be greater than Foo!'],
ISubInvariant)
# and if we set foo to a positive number and boo to 0, we'll
# get both errors!
o.foo = 1
o.bar = 0
for msg in msgs:
self.assertEquals(msg, error_msgs.pop(0))
# the tests
self.assertEquals(IInvariant.getTaggedValue('invariants'),
[ifFooThenBar])
self.assertEquals(IInvariant.validateInvariants(o), None)
o.bar = 27
self.assertEquals(IInvariant.validateInvariants(o), None)
o.foo = 42
self.assertEquals(IInvariant.validateInvariants(o), None)
del o.bar
errorsEqual(self, o, 1, ['If Foo, then Bar!'])
# nested interfaces with invariants:
self.assertEquals(ISubInvariant.getTaggedValue('invariants'),
[BarGreaterThanFoo])
o = InvariantC()
directlyProvides(o, ISubInvariant)
o.foo = 42
# even though the interface has changed, we should still only have one
# error.
errorsEqual(self, o, 1, ['If Foo, then Bar!'], ISubInvariant)
# however, if we set foo to 0 (Boolean False) and bar to a negative
# number then we'll get the new error
o.foo = 2
o.bar = 1
errorsEqual(self, o, 1, ['Please, Boo MUST be greater than Foo!'],
ISubInvariant)
# and if we set foo to a positive number and boo to 0, we'll
# get both errors!
o.foo = 1
o.bar = 0