修补datetime.timedelta.total_seconds

Question

我为web应用程序编写单元测试，我应该更改函数等待时间TIME_TO_WAIT来测试一些模块。代码示例：

import time
from datetime import datetime as dt

def function_under_test():
    TIME_TO_WAIT = 300
    start_time = dt.now()
    while True:
        if (dt.now() - start_time).total_seconds() > TIME_TO_WAIT:
            break
        time.sleep(1)

我看到了一个用datetime.timedelta.total_seconds()的补丁来解决这个问题的方法，但是我不知道如何正确地做到这一点。

谢谢。

Answer 1

正如我在评论中所写的-为了控制测试执行的速度，我将修补dt和time，如下所示：

from unittest import TestCase
from mock import patch
from datetime import datetime

from tested.module import function_under_test

class FunctionTester(TestCase):

    @patch('tested.module.time')
    @patch('tested.module.dt')
    def test_info_query(self, datetime_mock, time_mock):
        datetime_mock.now.side_effect = [
            datetime(year=2000, month=1, day=1, hour=0, minute=0, second=0),
            datetime(year=2000, month=1, day=1, hour=0, minute=5, second=0),
            # this should be over the threshold
            datetime(year=2000, month=1, day=1, hour=0, minute=5, second=1),
        ]
        value = function_under_test()
        # self.assertEquals(value, ??)
        self.assertEqual(datetime_mock.now.call_count, 3)