在 Python 中模拟套接字连接

问题描述

我正在尝试为 python 中的一个类编写单元测试.该类在 init 上打开一个 tcp 套接字.我试图对此进行模拟，以便我可以断言使用正确的值调用连接，但显然在单元测试中实际上并没有发生.我已经厌倦了 MagicMock、补丁等，但我还没有找到解决方案.

I am trying to write unit tests for a class in python. The class opens a tcp socket on init. I am trying to mock this out so that I can assert that connecting is called with the correct values but obviously doesn't actually happen in unit tests. I have tired MagicMock, patch, etc but I have not found a solution.

到目前为止，我的班级看起来像这样

My class so far looks like this

import socket

class MyClass(object):

    def __init__(self):
        self.tcp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.tcp_socket.connect('0.0.0.0', '6767')

推荐答案

如果只想断言 connect 被正确调用，那么简单的 as

If you just want to assert that connect is called correctly, it's a simple as

import mock
import socket

class MyClass(object):

    def __init__(self):
        self.tcp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.tcp_socket.connect('0.0.0.0', '6767')

with mock.patch('socket.socket'):
    c = MyClass()
    c.tcp_socket.connect.assert_called_with('0.0.0.0', '6767')

如果您必须先导入模块才能访问 MyClass，则需要稍微调整补丁:

If you have to import a module first to access MyClass, you'll need to adjust the patch slightly:

from mymodule import MyClass
import mock

with mock.patch('mymodule.socket.socket'):
    c = MyClass()
    c.tcp_socket.connect.assert_called_with('0.0.0.0', '6767')