Question

考虑模拟返回文件对象的打开调用

>>> from unittest.mock import MagicMock
>>> mock_fi = MagicMock()
>>> mock_op = MagicMock()  
>>> mock_op.return_value = mock_file
>>> 
>>> f = mock_op()
>>> f is mock_fi
True

到目前为止一切顺利。 mock_calls的内容是

>>> mock_fi.mock_calls
[]
>>> mock_op.mock_calls
[call()]

也没关系。现在考虑循环文件

中的行

>>> for l in mock_fi:
...     break
... 
>>> mock_fi.mock_calls
[call.__iter__()]

这是预期的。我不明白的是为什么mock_op对象也记录了__iter__调用

>>> mock_op.mock_calls
[call(), call().__iter__()]

Answer 1

根据文档，mock_calls记录了对象的所有调用，以及对该对象的调用返回的对象。

例如：

>>> my_mock = MagicMock()
>>> my_mock.foo().bar()
<MagicMock name='mock.foo().bar()' id='140397146563528'>
>>> my_mock.mock_calls
[call.foo(), call.foo().bar()] # bar() was not called directly on my_mock,
                               # yet, it is included since it was called on 
                               # the return value of foo() which is a direct 
                               # access to my_mock

在原始代码中，mock_op.mock_calls报告了call().__iter__() __iter__() mock_fi上的show。

在for循环中模拟open / file

1 个答案: