python 模拟第三方模块

Question

我正在尝试测试一些处理推文的类。我使用 Sixohsix twitter 来处理 Twitter API。我有一个类充当 Twitter 类的外观，我的想法是模拟实际的 Sixohsix 类，通过随机生成新推文或从数据库检索它们来模拟推文的到达。

我的外观看起来像:

from twitter import TwitterStream


class TwitterFacade(object):
    def __init__(self, dev='soom'):
        self._auth = OAuth(dev_keys["ACCESS_TOKEN"], dev_keys["ACCESS_SECRET"],   dev_keys["CONSUMER_KEY"], dev_keys["CONSUMER_SECRET"])

    def tweets(self, callback=None, users=[], terms=[], locations=[], count=5):
        t = TwitterStream(auth=self._auth)

        args = {}
        if users:     args['follow']    = ",".join(users)
        if terms:     args['track']     = ",".join(terms)
        if locations: args['locations'] = ",".join(str(l) for l in locations)

        # this controls the general loop, it re-enters if there was an exception,
        # otherwise the for loop should take care of looping trough the tweets
        cant = count
        while cant > 0:
            try:
                iterator = t.statuses.filter(**args)
                for twit in iterator:
                    if twit.get('text'):
                        callback(twit)
                        cant -= 1
                        if cant == 0:
                            iterator.close()
                            break
            except Exception as e:
                print e
                #some error handling code

因此，如果在单元测试中我想测试某个对推文执行某些操作的模块，我将如何模拟 TwitterStream 类？我尝试过使用模拟:

from mock import patch
from twitter_facade import TwitterFacade


class TwitterStreamProxy(object):
    def __init__(self):
        pass
        #some code for dealing with statuses.filter(..)


@patch('twitter.TwitterStream', TwitterStreamProxy())
def test_filter_on_tweets():
    facade = TwitterFacade()
    facade.tweets(somemethod, [], ['term1', 'term2'], [], count=50)

def somemethod(tweet):
    #some logic in here

这不起作用，twitter api 仍然被调用。我本以为，由于我没有向模拟类添加任何代码，我会收到错误或其他错误，但改为调用 Sixohsix twitter 类。

Answer 1

您需要修补本地对象；您的模块有一个对 TwitterStream 对象的引用，请修补:

@patch('yourmodule.TwitterStream', TwitterStreamProxy())

查看模拟 Where to Patch文档。