# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for L{twisted.persisted.styles}.
"""
import pickle
from twisted.trial import unittest
from twisted.persisted.styles import unpickleMethod, _UniversalPicklingError
class Foo:
"""
Helper class.
"""
def method(self):
"""
Helper method.
"""
class Bar:
"""
Helper class.
"""
def sampleFunction():
"""
A sample function for pickling.
"""
lambdaExample = lambda x: x
class UniversalPicklingErrorTests(unittest.TestCase):
"""
Tests the L{_UniversalPicklingError} exception.
"""
def raise_UniversalPicklingError(self):
"""
Raise L{UniversalPicklingError}.
"""
raise _UniversalPicklingError
def test_handledByPickleModule(self):
"""
Handling L{pickle.PicklingError} handles
L{_UniversalPicklingError}.
"""
self.assertRaises(pickle.PicklingError,
self.raise_UniversalPicklingError)
def test_handledBycPickleModule(self):
"""
Handling L{cPickle.PicklingError} handles
L{_UniversalPicklingError}.
"""
try:
import cPickle
except ImportError:
raise unittest.SkipTest("cPickle not available.")
else:
self.assertRaises(cPickle.PicklingError,
self.raise_UniversalPicklingError)
class UnpickleMethodTests(unittest.TestCase):
"""
Tests for the unpickleMethod function.
"""
def test_instanceBuildingNamePresent(self):
"""
L{unpickleMethod} returns an instance method bound to the
instance passed to it.
"""
foo = Foo()
m = unpickleMethod('method', foo, Foo)
self.assertEqual(m, foo.method)
self.assertIsNot(m, foo.method)
def test_instanceBuildingNameNotPresent(self):
"""
If the named method is not present in the class,
L{unpickleMethod} finds a method on the class of the instance
and returns a bound method from there.
"""
foo = Foo()
m = unpickleMethod('method', foo, Bar)
self.assertEqual(m, foo.method)
self.assertIsNot(m, foo.method)
def test_primeDirective(self):
"""
We do not contaminate normal function pickling with concerns from
Twisted.
"""
def expected(n):
return "\n".join([
"c" + __name__,
sampleFunction.__name__, "p" + n, "."
]).encode("ascii")
self.assertEqual(pickle.dumps(sampleFunction, protocol=0),
expected("0"))
try:
import cPickle
except:
pass
else:
self.assertEqual(
cPickle.dumps(sampleFunction, protocol=0),
expected("1")
)
def test_lambdaRaisesPicklingError(self):
"""
Pickling a C{lambda} function ought to raise a L{pickle.PicklingError}.
"""
self.assertRaises(pickle.PicklingError, pickle.dumps, lambdaExample)
try:
import cPickle
except:
pass
else:
self.assertRaises(cPickle.PicklingError, cPickle.dumps,
lambdaExample)