如何在 Python 中模拟 redis 客户端?

2022-01-08 00:00:00 python mocking unit-testing python-mock

问题描述

我刚刚发现一堆单元测试失败了，因为开发人员没有在测试中模拟出对 redis 客户端的依赖.我正在努力解决这个问题，但我自己也遇到了困难.

I just found that a bunch of unit tests are failing, due a developer hasn't mocked out the dependency to a redis client within the test. I'm trying to give a hand in this matter but have difficulties myself.

该方法写入一个redis客户端:

The method writes to a redis client:

redis_client = get_redis_client()
redis_client.set('temp-facility-data', cPickle.dumps(df))

稍后在断言中检索结果:

Later in the assert the result is retrieved:

res = cPickle.loads(get_redis_client().get('temp-facility-data'))
expected = pd.Series([set([1, 2, 3, 4, 5])], index=[1])
assert_series_equal(res.variation_pks, expected)

我成功地修补了redis客户端的get()和set().

I managed to patch the redis client's get() and set() successfully.

@mock.patch('redis.StrictRedis.get')
@mock.patch('redis.StrictRedis.set')
def test_identical(self, mock_redis_set, mock_redis_get):
    mock_redis_get.return_value = ???
    f2 = deepcopy(self.f)
    f3 = deepcopy(self.f)
    f2.pk = 2
    f3.pk = 3
    self.one_row(f2, f3)

但我不知道如何将 get() 的 return_value 设置为 set() 将在代码中设置的值，以便测试通过.

but I don't know how to set the return_value of get() to what the set() would set in the code, so that the test would pass.

现在这条线没有通过测试:

Right now this line fails the test:

res = cPickle.loads(get_redis_client().get('temp-facility-data'))
TypeError: must be string, not MagicMock

有什么建议吗?

解决方案

认为你可以使用副作用在本地字典中设置和获取值

Think you can use side effect to set and get value in a local dict

data = {}
def set(key, val):
    data[key] = val

def get(key):
    return data[key]

mock_redis_set.side_effect = set
mock_redis_get.side_effect = get

未对此进行测试，但我认为它应该可以满足您的需求

not tested this but I think it should do what you want

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