在Python单元测试中集成模拟和补丁

如何解决在Python单元测试中集成模拟和补丁

我有一个带有一些我要为其编写单元测试用例的方法的类。对于最小的可重现示例，我附上了该类中的3种方法：

我正在测试的类的方法：

class WebViewLincSession(object):
    def renew_session_id(self,request):
            session = request.getSession()
            new_session_key = self.get_token()
            while new_session_key in session.guard.sessions:  # just in case the key is already used
                new_session_key = self.get_token()
            session.guard.sessions.pop(session.uid)  # remove the current session
            session.uid = new_session_key  # update the key
            session.guard.sessions[new_session_key] = session  # add session back with the new key
            request.addCookie(session.guard.cookieKey,new_session_key,path='/',secure=True,httpOnly=True)  # send updated cookie value
    def set_nonce(self,request):
        '''
        create a nonce value and send it as cookie
        '''
        if self._nonce_key is None:
            if self._NONCE_FOR_TEST:
                self._nonce_key = 'ecnon_for_test'
            else:
                self._nonce_key = 'ecnon_' + self.get_token()
            
        new_nonce_value = self.get_token()
        while new_nonce_value in self._nonce:  # just in case the value is already used
            new_nonce_value = self.get_token()
        
        now = time()
        stay_alive = now + self._STAY_ALIVE

        # reset timeout value for all existing nonces         
        for key in self._nonce.keys():
            if self._nonce[key] > stay_alive:
                self._nonce[key] = stay_alive
        
        self._nonce[new_nonce_value] = now + self._NONCE_TIMEOUT
        
        request.addCookie(self._nonce_key,new_nonce_value,httpOnly=True)  # send updated cookie value
        
        return new_nonce_value


    def get_valid_nonce(self):
        now = time()
        return [nonce for nonce in self._nonce.keys() if self._nonce[nonce] > now]

我的测试课程如下：

from __future__ import (division,absolute_import,with_statement)

from time import sleep

from mock import patch,MagicMock,mock,Mock
from requests.sessions import Session
from twisted.trial.unittest import TestCase

from viewlinc.webserver.web_viewlinc_session import WebViewLincSession


class MockGuard(object):
    '''Mock guard object for testing'''
    def __init__(self,*ags,**kwargs):
        ''' class constructor
        '''
        super(MockGuard,self).__init__(*ags,**kwargs)
        self.cookieKey = 'test_cookie_key'
        self.sessions = {'_test_session_': {}}

class MockSession(object):
    '''Mock session object for testing'''
    def __init__(self,**kwargs):
        ''' class constructor
        '''
        super(MockSession,**kwargs)
        self.guard = MockGuard()
        self.uid = '_test_session_'

class MockRequest(object):
    '''Mock Request object for testing'''
    def __init__(self,**kwargs):
        ''' class constructor
        '''
        super(MockRequest,**kwargs)
        self.session = MockSession()
        self.cookies = {}
  
    def getSession(self):
        ''' returns session object
        '''
        return self.session
          
    def addCookie(self,key,value,httpOnly=True,expires=None):
        ''' add/replace cookie
        '''
        self.cookies[key] = {
            'value': value,'path': path,'secure': secure,'httpOnly': httpOnly,'expires': expires
        }
          
    def getCookie(self,key):
        ''' retrieve a cookie
        '''
        cookie = self.cookies.get(key,{'value': None})
        return cookie['value']

class WebViewLincSessionTests(TestCase):
    '''Test WebViewLincSession methods'''

    def __init__(self,**kwargs):
        ''' class constructor
        '''
        super(WebViewLincSessionTests,**kwargs)
        self.request = MockRequest()
        self.web_session = WebViewLincSession()
    


    def test_02_renew_session_id(self):
        '''Test renew_session_id
        '''
        self.web_session.renew_session_id(self.request)
        session = self.request.session
        return self.assertTrue(session.uid != '_test_session_' and session.uid in session.guard.sessions,'renew_session_id failed')

    def test_03_set_nonce(self):
        '''Test set_nonce
        '''
        self.web_session.set_nonce(self.request)
        
        return self.assertTrue(len(self.request.cookies) > 0,'set_nonce failed.')


    def test_04_get_valid_nonce(self):
        '''Test get_valid_nonce
        '''
        # use a clean session
        web_session = WebViewLincSession()
        web_session.set_nonce(self.request)
        web_session.set_nonce(self.request)
        valid_nonce = web_session.get_valid_nonce()

        self.assertTrue(len(valid_nonce) == 2,'Expecting 2 valid nonces.')
        
        sleep(16)
        valid_nonce = web_session.get_valid_nonce()
        
        return self.assertTrue(len(valid_nonce) == 1,'Expecting 1 valid nonce.')

我想要的：

我想尽可能在​​测试类中使用模拟/补丁。这可能意味着将MockGuard，MockSession和MockRequest替换为模拟实例。我想看看如何改进它以使用python unittest包中的模拟/补丁。

解决方法

好的，尝试给您一个主意。在测试中，您为测试创建了伪造的addCookie方法，但是仅使用它来检查如何调用addCookie。因此，例如，您的测试3和4可以重写：

   def test_03_set_nonce(self):
        request = mock.Mock()
        self.web_session.set_nonce(request)
        # we only need to know that it was called once
        request.addCookie.assert_called_once()

   def test_04_get_valid_nonce(self):
        request = mock.Mock()
        web_session = WebViewLincSession()
        web_session.set_nonce(request)
        web_session.set_nonce(request)
        # check that addCookie it has been called twice
        self.assertEqual(2,request.addCookie.call_count)
        
        valid_nonce = web_session.get_valid_nonce()
        ... # the rest is not dependent on mocks

在其他测试中，您可能还必须检查调用中使用的参数。您始终必须定义实际要测试的内容，然后设置模拟，以便仅测试该功能。

还请注意，在某些情况下，像您一样使用额外的模拟类可能很有意义-如果最适合您，那没有什么错。