相关疑难解决方法(0)

我应该如何自定义unittest.mock.mock_open来处理这段代码？

file: impexpdemo.py
def import_register(register_fn):
    with open(register_fn) as f:
        return [line for line in f]

我第一次尝试尝试read_data.

class TestByteOrderMark1(unittest.TestCase):
    REGISTER_FN = 'test_dummy_path'
    TEST_TEXT = ['test text 1\n', 'test text 2\n']

    def test_byte_order_mark_absent(self):
        m = unittest.mock.mock_open(read_data=self.TEST_TEXT)
        with unittest.mock.patch('builtins.open', m):
            result = impexpdemo.import_register(self.REGISTER_FN)
            self.assertEqual(result, self.TEST_TEXT)

这失败了,大概是因为代码不使用read,readline或readlines.unittest.mock.mock_open 的文档说:"read_data是要返回的文件句柄的read(),readline()和readlines()方法的字符串.对这些方法的调用将从read_data中获取数据,直到它耗尽为止这些方法的模拟非常简单.如果你需要更多地控制你要测试代码的数据,你需要自己定制这个模拟.默认情况下,read_data是一个空字符串."

由于文件没有给出暗示上会需要什么样定制我试图return_value和side_effect.都没有奏效.

class TestByteOrderMark2(unittest.TestCase):
    REGISTER_FN = 'test_dummy_path'
    TEST_TEXT = ['test text 1\n', 'test text 2\n']

    def test_byte_order_mark_absent(self):
        m = unittest.mock.mock_open()
        m().side_effect = self.TEST_TEXT
        with unittest.mock.patch('builtins.open', m):
            result = impexpdemo.import_register(self.REGISTER_FN) …