python - 如何创建 Selenium Webdriver 测试以验证元素不存在？

Question

我在 Selenium Webdriver 中为我的 Django 应用程序创建单元测试。

我有一个从数据库中删除主题的 AJAX 方法。我正在尝试弄清楚如何验证已删除的主题不再出现在页面上。

我正在 try catch 当 Webdriver 找不到元素时应该生成的异常:selenium.common.exceptions.NoSuchAttributeException

相反，我看到了一个错误:

*** URLError: <urlopen error timed out>

这是我设置测试的方式:

from selenium import webdriver
from django.utils import unittest  

class TestAuthentication(unittest.TestCase):    
    scheme = 'http'    
    host = 'localhost'    
    port = '4444'    


    def setUp(self):    
        self._driver = webdriver.Firefox()    
        self._driver.implicitly_wait(10)    

    def login_as_Kallie(self):    
        # Kallie has manual login    
        self._driver.get('http://localhost:8000/account/signin/')    
        user = self._driver.find_element_by_id('id_username')    
        user.send_keys("Kallie")    
        password = self._driver.find_element_by_id('id_password')    
        password.send_keys('*********')    
        submit = self._driver.find_element_by_id('blogin')    
        submit.click()    

    def test_Kallie_can_delete_topic(self):    
        self.login_as_Kallie()    
        self._driver.find_element_by_link_text("Topic to delete").click()    
        self._driver.find_element_by_xpath("/html/body/div/div[4]/div/div/div[2]/div/table/tbody/tr/td[2]/div/div[3]/span[5]/a").click()    
        self._driver.find_element_by_class_name('dialog-yes').click()    
        self._driver.get("http://localhost:8000/questions/")    
        # this is the Python exception to catch: selenium.common.exceptions.NoSuchAttributeException    
        self.assertRaises('selenium.common.exceptions.NoSuchAttributeException', self._driver.find_element_by_link_text("Topic to delete"))    

    def tearDown(self):    
        self._driver.quit()    

如何测试页面元素是否缺失？

Answer 1

from selenium.common.exceptions import NoSuchElementException

with self.assertRaises(NoSuchElementException):
    self._driver.find_element_by_link_text("Topic to delete")