Refs #22955 -- Added test for admin's many-to-many widget refresh data loss bug.

        self.assertSelectOptions('#id_alumni_from', expected_unselected_values)

        self.assertSelectOptions('#id_alumni_to', expected_selected_values)

    def test_refresh_page(self):

        """

        Horizontal and vertical filter widgets keep selected options on page

        reload (#22955).

        """

        self.school.students.add(self.arthur, self.jason)

        self.school.alumni.add(self.arthur, self.jason)

        self.admin_login(username='super', password='secret', login_url='/')

        change_url = reverse('admin:admin_widgets_school_change', args=(self.school.id,))

        self.selenium.get(self.live_server_url + change_url)

        options_len = len(self.selenium.find_elements_by_css_selector('#id_students_to > option'))

        self.assertEqual(options_len, 2)

        # self.selenium.refresh() or send_keys(Keys.F5) does hard reload and

        # doesn't replicate what happens when a user clicks the browser's

        # 'Refresh' button.

        self.selenium.execute_script("location.reload()")

        self.wait_page_loaded()

        options_len = len(self.selenium.find_elements_by_css_selector('#id_students_to > option'))

        self.assertEqual(options_len, 2)

class HorizontalVerticalFilterSeleniumChromeTests(HorizontalVerticalFilterSeleniumFirefoxTests):

    webdriver_class = 'selenium.webdriver.chrome.webdriver.WebDriver'