Pytest如何直接调用带有fixture参数的函数

Question

我正在为网络应用构建一个测试套件。我正在使用如下固定装置：

import pytest
from selenium import webdriver
from common import Common

@pytest.fixture(scope='module')
def driver(module, headless=True):
    opts = webdriver.FirefoxOptions()
    opts.add_argument('--headless') if headless else None
    driver = webdriver.Firefox(options=opts)
    driver.get('http://localhost:8080/request')
    yield driver
    driver.quit()

def test_title(driver):
    assert driver.title == 'abc'

if __name__ == '__main__':
    test_title() #what I need to execute to see if everything is fine

假设我需要通过直接在if __name__ == '__main__': 中运行此模块来查看我的test_title 函数是否正在做它需要做的事情。如何使用作为参数传入的驱动程序调用test_title()？

像下面这样调用test_title：

if __name__ == '__main__':
    test_title(driver(None, False))

python 产生下面提到的错误：

(virtual) sflash@debian:~/Documents/php/ufj/ufj-test$ ./test_r*
Traceback (most recent call last):
  File "./test_request.py", line 30, in <module>
    test_empty_all(driver(None, headless=True))
  File "/home/sflash/Documents/php/ufj/ufj-test/virtual/lib/python3.7/site-packages/_pytest/fixtures.py", line 1176, in result
    fail(message, pytrace=False)
  File "/home/sflash/Documents/php/ufj/ufj-test/virtual/lib/python3.7/site-packages/_pytest/outcomes.py", line 153, in fail
    raise Failed(msg=msg, pytrace=pytrace)
Failed: Fixture "driver" called directly. Fixtures are not meant to be called directly,
but are created automatically when test functions request them as parameters.
See https://docs.pytest.org/en/stable/fixture.html for more information about fixtures, and
https://docs.pytest.org/en/stable/deprecations.html#calling-fixtures-directly about how to update your code.

Answer 1

正如在 cmets 中所讨论的，fixture 不能直接调用 - 它们只能与 pytest 一起使用。

要直接从您的代码中调用测试，您可以在__main__ 部分中调用pytest.main()，这与在命令行中调用pytest 的效果相同。任何命令行选项都可以作为参数添加到调用中（作为列表），例如：

if __name__ == '__main__':
    pytest.main(['-vv', 'test.py::test_title'])

要使用涉及 pytest 的驱动程序（这是您的意图），您必须提取驱动程序逻辑并从夹具和主程序中分别调用它：

import pytest
from selenium import webdriver
from common import Common

def get_driver(headless=True):
    opts = webdriver.FirefoxOptions()
    opts.add_argument('--headless') if headless else None
    driver = webdriver.Firefox(options=opts)
    driver.get('http://localhost:8080/request')
    return driver
):

@pytest.fixture(scope='module')
def driver(module):
    yield get_driver()
    driver.quit()

def test_title(driver):
    assert driver.title == 'abc'

if __name__ == '__main__':
    driver = get_driver()
    test_title() 
    driver.quit()

请注意，这仅在测试功能不依赖任何 pytest 特定的东西（例如自动应用的固定装置）时才有效。
另请注意，您不能像在示例中那样在夹具中使用参数，因为您无法提供参数。相反，您可以使用parametrized fixtures。