Python pytest mock assert_调用_，类函数失败

我计划使用pytest和pytest mock来验证Python代码。作为一个新手，编写了一个示例代码来验证类上的mock并看到失败。我想知道出了什么问题

src/main.py

class Main(object):
    def __init__(self, my_var=None):
        self.var = my_var

    def internal_func(self, var=10):
        my_var = var + 20
        return my_var

    def test_func(self):
        val = self.internal_func(20)
        return val + 40

测试/测试_main.py

    import pytest
    from pytest_mock import mocker
    from src.main import Main

    def new_func(cls, *args, **kwargs):
        return 2

    def test_main_mock(mocker):
        mocker.patch.object(Main, 'internal_func')
        val = Main().test_func()
        assert Main.internal_func.assert_called_with(20)

它失败，出现以下错误

    ======================================================================================== FAILURES ========================================================================================
    _____________________________________________________________________________________ test_main_mock _____________________________________________________________________________________

    mocker = <pytest_mock.MockFixture object at 0x7f34f490d8d0>

        def test_main_mock(mocker):
            mocker.patch.object(Main, 'internal_func')
            main = Main()
            val = main.test_func()
        #    assert val == 80
    >       assert Main.internal_func.assert_called_with(20)
    E       AssertionError: assert None
    E        +  where None = <bound method MagicMock.wrap_assert_called_with of <MagicMock name='internal_func' id='139865418160784'>>(20)
    E        +    where <bound method MagicMock.wrap_assert_called_with of <MagicMock name='internal_func' id='139865418160784'>> = <MagicMock name='internal_func' id='139865418160784'>.assert_called_with
    E        +      where <MagicMock name='internal_func' id='139865418160784'> = Main.internal_func

    tests/test_main.py:13: AssertionError

======================================================================================================================================================失败========================================================================================
_____________________________________________________________________________________测试主模拟_____________________________________________________________________________________
嘲弄者=
def测试主模拟（模拟）：
mocker.patch.object（Main，“internal_func”）
main=main（）
val=main.test_func（）
#断言值==80
>assert Main.internal函数assert函数调用（20）
断言错误：断言无
E+其中无=（20）
E+where=.assert_调用_
E+其中=Main.internal_func
tests/test_main.py:13:AssertionError

在修补函数生效之前，必须设置返回值或副作用

def test_main_mock(mocker):
    # mock internal_func of class Main
    mocked_internal_func = mocker.patch.object(Main, 'internal_func')
    # assign return_value or side_effect
    mocked_internal_func.return_value = -10
    # class instance
    ma = Main()
    val = ma.test_func()

    assert ma.internal_func.assert_called_with(20)

更正错误，断言不应与

assert\u一起使用，称为\u with

，它们是独立的断言

---

仍然是相同的错误>assert ma.internal_func.assert_called_with（20）E AssertionError:assert None E+where None=（20）E+where=.assert_called_with E+where=.internal_funcomocker=def test_main_mock（mocker）：m=mocker.patch.object（main，'internal_func'）m.return\u value=-10 ma=Main（）val=ma.test\u func（）>assert ma.internal\u func.assert\u调用了带有（20）E AssertionError:assert的None@suri，你是对的，我把2个断言混在一起了，这就是它失败的原因

    assert val == 30
    mocked_internal_func.assert_called
    ma.internal_func.assert_called_with(20)
    mocked_internal_func.assert_called_with(20)