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

Question

我试图用来py.test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，并在模拟对象search_s()上调用a 时控制它返回的内容。

我以为这会做我想要的，但是测试失败了，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

您可以直接使用补丁（并且您的结构有些不对劲）：

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