如何使用 pytest-mock 模拟 class 并控制 py.test 中的返回值？

Question

我正在尝试使用 py.test 来测试一些执行各种 LDAP 搜索和修改的代码。

我正在使用 pytest-mock，但我无法理解如何模拟 LDAP 对象的创建，以及如何在 search_s() 时控制它 returns在模拟对象上调用。

我以为这会做我想做的事，但测试失败，计数显示生成器函数 find_users() 永远不会产生任何结果。

import pytest
# Here is some code to simply test mocking out ldap.initialize(), and
# controlling the return value from calls to search_s()
import ldap

def find_users(ldap_url, admin_user, admin_password, userbase):
    lobj = ldap.initialize(ldap_url)
    lobj.simple_bind_s(admin_user, admin_password)
    for i in lobj.search_s(userbase, ldap.SCOPE_SUBTREE, '*'):
        yield i[1]['uid'][0]

class TestMocking:

    @pytest.fixture()
    def no_ldap(self, mocker):
        return mocker.patch('ldap.initialize')


    def test_ad_one_user(self, no_ldap):
        # try and modify how search_s() would return
        no_ldap.search_s.return_value = ('', {'uid': ['happy times']})
        count = 0 
        for i in find_users('', '', '', ''):
            count += 1
            assert i=='happy times'
        assert count == 1

Answer 1

我认为您可能对 https://docs.python.org/3/library/unittest.mock.html 和 pytest 猴子补丁感到困惑。我不认为两者的行为方式相同。

您可以使用模拟补丁使其工作 (https://docs.python.org/3/library/unittest.mock.html#unittest.mock.patch)

@pytest.fixture()
def no_ldap(self):
    patcher = mock.patch('ldap.initialize')
    patcher.start()
    yield patcher
    patcher.stop()

Answer 2

你可以直接使用补丁（你的结构有些问题）：

from mock import patch, Mock
import pytest
# Here is some code to simply test mocking out ldap.initialize(), and
# controlling the return value from calls to search_s()
import ldap

def find_users(ldap_url, admin_user, admin_password, userbase):
    lobj = ldap.initialize(ldap_url)
    lobj.simple_bind_s(admin_user, admin_password)
    for i in lobj.search_s(userbase, ldap.SCOPE_SUBTREE, '*'):
        yield i[1]['uid'][0]

class TestMocking:

    @patch('ldap.initialize')
    def test_ad_one_user(self, no_ldap):
        # try and modify how search_s() would return
        data = [('', {'uid': ['happy times']})]
        search_s = Mock(return_value=data)
        no_ldap.return_value = Mock(search_s=search_s)
        count = 0
        for i in find_users('', '', '', ''):
            count += 1
            assert i=='happy times'
        assert count == 1

如何使用 pytest-mock 模拟 class 并控制 py.test 中的返回值？

How do I mock a class and control a returned value in py.test with pytest-mock?

python

mocking

pytest