問題描述

我一直在嘗試找到一種同時使用模擬裝飾器和 pytest capsys 的方法，但我找不到正確的方法.

I have being trying to find a way to use mocking decorators and pytest capsys at the same time but I wasn't able to find the right way to do it.

import pytest
import requests_mock


@requests_mock.mock()
def test_with_mock(m):
    pass

def test_with_capsys(capsys):
    pass


# how to write a test that works with both?

推薦答案

如 request-mock 的文檔:

As stated in the request-mock's docs:

pytest 有自己的注冊和加載自定義夾具的方法.requests-mock 提供了一個用 pytest 注冊的外部夾具，因此只需將其指定為參數(shù)即可使用.無需導入requests-mock，只需要安裝并指定參數(shù)requests_mock.

pytest has its own method of registering and loading custom fixtures. requests-mock provides an external fixture registered with pytest such that it is usable simply by specifying it as a parameter. There is no need to import requests-mock it simply needs to be installed and specify the argument requests_mock.

然后，fixture 提供與 requests_mock.Mocker 相同的接口，讓您可以按預期使用 requests-mock.

The fixture then provides the same interface as the requests_mock.Mocker letting you use requests-mock as you would expect.

>>> import pytest
>>> import requests

>>> def test_url(requests_mock):
...     requests_mock.get('http://test.com', text='data')
...     assert 'data' == requests.get('http://test.com').text
...

所以只需使用 requests_mock 夾具而不是裝飾器:

So just use the requests_mock fixture instead of the decorator:

def test_with_mock_and_capsys(requests_mock, capsys):
    pass

背景

pytest 不能與向測試函數(shù)添加位置參數(shù)的函數(shù)裝飾器一起使用.pytest 考慮所有參數(shù)

Background

pytest doesn't play along with function decorators that add positional arguments to the test function. pytest considers all arguments that

• 不像在實例或類方法中那樣綁定到實例或類型；
• 沒有默認值；
• 不與 functools.partial;
綁定
• 不替換為 unittest.mock 模擬

被替換為夾具值，如果沒有找到適合任何參數(shù)的夾具，則會失敗.所以像

to be replaced with fixture values, and will fail if it doesn't find a suitable fixture for any argument. So stuff like

import functools
import pytest


def deco(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        args += ('spam',)
        return func(*args, **kwargs)
    return wrapper


@deco
def test_spam(spam_arg):
    assert True

會失敗，而這正是 requests-mock 所做的.一種解決方法是通過關鍵字 args 傳遞 mocker:

will fail, and this is exactly what requests-mock does. A workaround to that would be passing the mocker via keyword args:

import pytest
import requests_mock


@requests_mock.Mocker(kw='m')
def test_with_mock_and_fixtures(capsys, **kwargs):
    m = kwargs['m']
    ...

但是既然 requests-mock 已經(jīng)提供了一個fixture，為什么還要使用裝飾器呢?

but since requests-mock already offers a fixture, why bother using the decorator?

這篇關于如何在具有模擬裝飾器的測試中使用 pytest capsys?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！