为什么我可以从其他文件中修补一个单元测试的类别的类？

Question

我有一个名为some.py的文件：

from dataclasses import dataclass
from some_folder.some_reader import SomeReader

class SomeClass:
    def __init__(self, url):
        self.reader = SomeReader(url)

和some_reader.py：

class SomeReader:
    def read_path(self, url):
        return "read_path"

和some_test.py：

from unittest.mock importpatch
from some_folder.some import SomeClass

@patch("some_folder.some_reader.SomeReader")
def test_some_class(mock_some_reader):
    SomeClass("")

当我运行some_test ，看来somereader实例化不是模拟对象，而是：

SomeReader
<class 'some_folder.some_reader.SomeReader'>

如果我将somereader放入some.py 。

Answer 1

参见在哪里进行修补

。

from some_folder.some_reader import SomeReader


class SomeClass:
    def __init__(self, url):
        self.reader = SomeReader(url)

​

class SomeReader:
    def read_path(self, url):
        return "read_path"

​

import unittest
from unittest.mock import patch
from some import SomeClass


class TestSome(unittest.TestCase):
    @patch("some.SomeReader")
    def test_some_class(self, mock_some_reader):
        some = SomeClass("")
        print(some.reader)

if __name__ == '__main__':
    unittest.main()

​

<MagicMock name='SomeReader()' id='4520784368'>
.
----------------------------------------------------------------------
Ran 1 test in 0.001s

OK