如何在Python中使用Mockito编写单元测试

Question

我是Python的新手，因此在Python中使用模仿还是有问题。

我的生产代码如下所示：

from stompest.config import StompConfig
from stompest.sync import Stomp


class Connector:
    def sendMessage(self):
        message = {'message'}
        dest = '/queue/foo'

    def _send(self, message='', dest=''):
        config = StompConfig(uri="tcp://localhost:61613")
        client = Stomp(config)
        client.connect()
        client.send(body=message, destination=dest,
                    headers='')
        client.disconnect()

如您所见，我想使用Stomp协议发送消息。 我的测试我想测试w，当我从Connector类调用send方法时，从Stompest库调用send方法将仅被调用一次。

我的单元测试如下：

from Connector import Connector

import unittest
from mockito import *
import stompest
from stompest.config import StompConfig
from stompest.sync import Stomp


class test_Connector(unittest.TestCase):
    def test_shouldInvokeConnectMethod(self):
        stomp_config = StompConfig(uri="tcp://localhost:61613")
        mock_stomp = mock(Stomp(stomp_config))

        connector = Connector()
        connector.sendMessage()
        verify(mock_stomp, times=1).connect()

当我在调试模式下运行测试时，我看到实例connect（）的方法被调用并且方法也发送了，但是作为测试的结果，我得到了：

Failure
Traceback (most recent call last):
  File "C:\development\systemtest_repo\robot_libraries\test_Connector.py", line 16, in test_shouldInvokeConnectMethod
    verify(mock_stomp, times=1).connect()
  File "C:\Python27\lib\site-packages\mockito\invocation.py", line 111, in __call__
    verification.verify(self, len(matched_invocations))
  File "C:\Python27\lib\site-packages\mockito\verification.py", line 63, in verify
    raise VerificationError("\nWanted but not invoked: %s" % (invocation))
VerificationError: 
Wanted but not invoked: connect()

我做错了什么？

Answer 1

您实际上并没有在模拟对象上调用connect方法-您只需检查它是否被调用即可。 该错误也说明了此问题， Wanted but not invoked: connect() 。 也许在调用verify之前添加对mock_stomp.connect()的调用将解决此问题：

mock_stomp = mock(Stomp(stomp_config))

# call the connect method first...
mock_stomp.connect()

connector = Connector()
connector.sendMessage()

# ...then check it was called
verify(mock_stomp, times=1).connect()

如果改为尝试检查是否已从Connector调用了模拟程序，则可能至少需要通过依赖注入来传递mock_stomp对象。 例如

class Connector:
  def __init__(self, stomp):
   self.stomp = stomp

  def sendMessage(self, msg):
    self.stomp.connect()
    # etc ...

在你的测试中

mock_stomp = mock(Stomp(stomp_config))
connector = Connector(mock_stomp)
connector.sendMessage()

verify(mock_stomp, times=1).connect()

否则，我看不到如何在断言所基于的同一mock_stomp实例上调用connect()方法。