Python Unittest：如何在类中初始化 selenium 并避免浏览器打开两次？

Question

考虑下面的示例，因为我在 setUp 方法中初始化驱动程序并在 test_login 中使用它，浏览器将打开两次，第一次在 setUp 期间打开，然后它将关闭并开始测试。

如果我从setUp 中删除逻辑并将其放入test_login，则驱动程序将在test_profile 和tearDown 中未定义

在不导致浏览器打开两次的情况下，初始化驱动程序并在整个课程中使用它的正确方法是什么？

from selenium import webdriver
import unittest
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager


class Test(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome(
            service=Service(ChromeDriverManager().install()))
        self.driver.get('https://example.com/login')
        self.current_url = self.driver.current_url
        self.dashboard_url = 'https://example.com/dashboard'

    def test_login(self):
        self.assertEqual(self.dashboard_url, self.current_url)
    
    def test_profile(self):
        self.driver.get('https://example.com/profile')
    
    def tearDown(self):
        self.driver.close()

Answer 1

您需要使用setUpClass / tearDownClass：

import unittest


class Test(unittest.TestCase):
    @classmethod
    def setUpClass(cls) -> None:
        print('setUpClass')

    @classmethod
    def tearDownClass(cls) -> None:
        print('tearDownClass')

    def setUp(self):
        print('setUp')

    def test_login(self):
        print('login')

    def test_profile(self):
        print('profile')

    def tearDown(self):
        print('tearDown')

Answer 2

您的代码工作正常。请在 setUp 和 tearDown 方法之前添加装饰器@classmethod。 此外，setUp 方法中的行 self.driver.get('https://example.com/login') 也存在问题。只需从那里删除它，然后创建一个新函数来保存该代码。

Answer 3

这是一个将 unittest.TestCase 与 Selenium 结合使用的示例。它具有 setUp() 和 tearDown() 步骤，它会获得您正在寻找的所需行为，尽管可能比您要求的更多。

你可以用python -m unittest运行它：

import sys
from selenium import webdriver
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.ui import WebDriverWait
from unittest import TestCase

class RefinedRawSelenium(TestCase):
    def setUp(self):
        self.driver = None
        options = webdriver.ChromeOptions()
        options.add_argument("--disable-notifications")
        if "linux" in sys.platform:
            options.add_argument("--headless=new")
        options.add_experimental_option(
            "excludeSwitches", ["enable-automation", "enable-logging"],
        )
        prefs = {
            "credentials_enable_service": False,
            "profile.password_manager_enabled": False,
        }
        options.add_experimental_option("prefs", prefs)
        self.driver = webdriver.Chrome(options=options)

    def tearDown(self):
        if self.driver:
            try:
                if self.driver.service.process:
                    self.driver.quit()
            except Exception:
                pass

    def wait_for_element_visible(
        self, selector, by="css selector", timeout=10
    ):
        try:
            return WebDriverWait(self.driver, timeout).until(
                EC.visibility_of_element_located((by, selector))
            )
        except Exception:
            raise Exception(
                "Element {%s} was not visible after %s seconds!"
                % (selector, timeout)
            )

    def wait_for_element_clickable(
        self, selector, by="css selector", timeout=10
    ):
        try:
            return WebDriverWait(self.driver, timeout).until(
                EC.element_to_be_clickable((by, selector))
            )
        except Exception:
            raise Exception(
                "Element {%s} was not visible/clickable after %s seconds!"
                % (selector, timeout)
            )

    def wait_for_element_not_visible(
        self, selector, by="css selector", timeout=10
    ):
        try:
            return WebDriverWait(self.driver, timeout).until(
                EC.invisibility_of_element((by, selector))
            )
        except Exception:
            raise Exception(
                "Element {%s} was still visible after %s seconds!"
                % (selector, timeout)
            )

    def open(self, url):
        self.driver.get(url)

    def click(self, selector, by="css selector", timeout=7):
        el = self.wait_for_element_clickable(selector, by=by, timeout=timeout)
        el.click()

    def type(self, selector, text, by="css selector", timeout=10):
        el = self.wait_for_element_clickable(selector, by=by, timeout=timeout)
        el.clear()
        if not text.endswith("
"):
            el.send_keys(text)
        else:
            el.send_keys(text[:-1])
            el.submit()

    def assert_element(self, selector, by="css selector", timeout=7):
        self.wait_for_element_visible(selector, by=by, timeout=timeout)

    def assert_text(self, text, selector="html", by="css selector", timeout=7):
        el = self.wait_for_element_visible(selector, by=by, timeout=timeout)
        self.assertIn(text, el.text)

    def assert_exact_text(self, text, selector, by="css selector", timeout=7):
        el = self.wait_for_element_visible(selector, by=by, timeout=timeout)
        self.assertEqual(text, el.text)

    def assert_element_not_visible(
        self, selector, by="css selector", timeout=7
    ):
        self.wait_for_element_not_visible(selector, by=by, timeout=timeout)

    def test_add_item_to_cart(self):
        self.open("https://www.saucedemo.com")
        self.type("#user-name", "standard_user")
        self.type("#password", "secret_sauce
")
        self.assert_element("div.inventory_list")
        self.assert_text("PRODUCTS", "span.title")
        self.click('button[name*="backpack"]')
        self.click("#shopping_cart_container a")
        self.assert_exact_text("YOUR CART", "span.title")
        self.assert_text("Backpack", "div.cart_item")
        self.click("#remove-sauce-labs-backpack")
        self.assert_element_not_visible("div.cart_item")
        self.click("#react-burger-menu-btn")
        self.click("a#logout_sidebar_link")
        self.assert_element("input#login-button")

# When run with "python" instead of "pytest" or "python -m unittest"
if __name__ == "__main__":
    from unittest import main
    main()

这是取自我在SeleniumBase/examples/migration/raw_selenium/refined_raw.py 中的示例

它实际上将成为我今年 SeleniumConf 2023 (https://seleniumconf.com/agenda/#python-selenium-fundamentals-to-frameworks-with-seleniumbase) 会议的一部分，在那里我将演示如何将其简化为类似这样的东西，它在导入的幕后使用unittest.TestCase：

from seleniumbase import BaseCase

class CleanSeleniumBase(BaseCase):
    def test_add_item_to_cart(self):
        self.open("https://www.saucedemo.com")
        self.type("#user-name", "standard_user")
        self.type("#password", "secret_sauce
")
        self.assert_element("div.inventory_list")
        self.assert_text("PRODUCTS", "span.title")
        self.click('button[name*="backpack"]')
        self.click("#shopping_cart_container a")
        self.assert_exact_text("YOUR CART", "span.title")
        self.assert_text("Backpack", "div.cart_item")
        self.click("#remove-sauce-labs-backpack")
        self.assert_element_not_visible("div.cart_item")
        self.click("#react-burger-menu-btn")
        self.click("a#logout_sidebar_link")
        self.assert_element("input#login-button")

# When run with "python" instead of "pytest"
if __name__ == "__main__":
    from pytest import main
    main([__file__, "-s"])

（那个使用seleniumbase.BaseCase，它继承了unittest.TestCase。示例来自SeleniumBase/examples/migration/raw_selenium/simple_sbase.py）