Tests for https://gist.github.com/926178

test_patch.py

from nose.tools import eq_
from patch import Patch
from unittest import TestCase


class SampleOld:

    SETTING = None

    def __init__(self, msg):
        self.msg = msg

    def hello(self):
        return self.msg

    def goodbye(self):
        return 'goodbye'


class SampleNew(object):

    SETTING = None

    def __init__(self, msg):
        self.msg = msg

    def hello(self):
        return self.msg

    def goodbye(self):
        return 'goodbye'


def outer_hello(self):
    return self.msg * 3


class TestPatch(TestCase):

    def shout(self):
        return self.msg.upper()

    def test_patch_new_instance(self):
        s = SampleNew('hello')
        eq_('hello', s.hello())
        with Patch(s, hello=outer_hello):
            eq_('hellohellohello', s.hello())
            eq_('hi', SampleNew('hi').hello())
        with Patch(s, hello=self.shout):
            eq_('HELLO', s.hello())
        eq_('hello', s.hello())

    def test_patch_old_instance(self):
        s = SampleOld('hello')
        eq_('hello', s.hello())
        with Patch(s, hello=outer_hello):
            eq_('hellohellohello', s.hello())
            eq_('hi', SampleOld('hi').hello())
        with Patch(s, hello=self.shout):
            eq_('HELLO', s.hello())
        eq_('hello', s.hello())

    def test_patch_new_class(self):
        s = SampleNew('hello')
        eq_('hello', s.hello())
        with Patch(SampleNew, hello=outer_hello):
            eq_('hellohellohello', s.hello())
            eq_('hihihi', SampleNew('hi').hello())
        with Patch(s, hello=self.shout):
            eq_('HELLO', s.hello())
        eq_('hello', s.hello())

    def test_patch_old_class(self):
        s = SampleOld('hello')
        eq_('hello', s.hello())
        with Patch(SampleOld, hello=outer_hello):
            eq_('hellohellohello', s.hello())
            eq_('hihihi', SampleOld('hi').hello())
        with Patch(s, hello=self.shout):
            eq_('HELLO', s.hello())
        eq_('hello', s.hello())

    def test_blank_out_methods_new(self):
        s = SampleNew('hello')
        eq_('hello', s.hello())
        with Patch(SampleNew, hello=None):
            eq_(None, s.hello())
        eq_('hello', s.hello())

    def test_blank_out_methods_old(self):
        s = SampleOld('hello')
        eq_('hello', s.hello())
        with Patch(SampleOld, hello=None):
            eq_(None, s.hello())
        eq_('hello', s.hello())

    def test_restore_from_null_property_new(self):
        with Patch(SampleNew, SETTING='stuff'):
            eq_('stuff', SampleNew.SETTING)
        eq_(None, SampleNew.SETTING)

    def test_restore_from_null_property_old(self):
        with Patch(SampleOld, SETTING='stuff'):
            eq_('stuff', SampleOld.SETTING)
        eq_(None, SampleOld.SETTING)