TDD/testing CSS and HTML

问题

I am stuck at this point below:

'''selenium.common.exceptions.NoSuchElementException: Message: Unable to locate element: .has-error'''

I tried to find a solution related to ".has-error" in order to get one of the functional tests via TDD to pass. Anyone ever experienced being stuck with that? Am I doing something wrong or missing a very little point? Your help would be appreciated!

Related code between my template/selenium:

Python part:

self.wait_for(lambda: self.assertEqual(self.browser.find_element_by_css_selector('.has-error').text,
            "You can't have an empty list item"))

html part:

            <div class="form-group has-error">
                    <span class="help-block">{{ error }}</span>
                </div>
     {% endif %}

来源：https://stackoverflow.com/questions/61740786/tdd-testing-css-and-html