How to test the display of banners on the website if…

Identification of locales and banners: Determine which locales (languages, regions) the site supports and for which locales banners are provided. Obtain a list of all possible banners for each locale.
Test cases: Create test cases for each combination of locale and banner. For each test case, describe:
- Input conditions (selected locale, user actions leading to banner display).
- Expected result (correct display of the specific banner for the selected locale).
- Acceptance criteria (e.g., correct text, image, clickability).
Manual testing:
- Manually switch the site locale via UI.
- Navigate through the site to trigger banner display in each locale.
- Visually verify the correctness of banner display (text, image, placement).
- Check clickability (redirect to the correct URL).
Automated testing:
- Use a web automation framework (e.g., Selenium, Cypress).
- Create tests that:
  - Set the required locale (via cookies, URL parameters, or site functionality).
  - Navigate to pages with banners.
  - Check for the presence and visibility of banner elements (e.g., via CSS selectors or XPath).
  - Verify banner content (text, image URL) matches the expected for the given locale (can compare with reference data).
  - Check the href attribute of the banner link.

# Example using Selenium WebDriver
from selenium import webdriver
from selenium.webdriver.common.by import By

def test_banner_display(driver, locale, expected_banner_text):
    # Set locale (example: via cookies)
    driver.add_cookie({'name': 'locale', 'value': locale})
    driver.refresh()

    # Navigate to the page with the banner
    driver.get("https://your-website.com/page-with-banner")

    # Find the banner element (example: by CSS class)
    banner_element = driver.find_element(By.CSS_SELECTOR, ".banner-class")

    # Check banner text
    assert banner_element.text == expected_banner_text, f"Banner text does not match for locale {locale}"

    # Check banner link URL (if present)
    banner_link = banner_element.find_element(By.TAG_NAME, "a").get_attribute("href")
    # Add validation for banner_link against expected value for this locale

Testing on different devices and browsers: Ensure banners display correctly across various browsers and screen sizes/devices for each locale.
Content testing: Verify that banner text is correctly translated for each locale, free of grammatical errors, and images match regional cultural features (if necessary).
Regression testing: Include banner display tests for different locales in the regression suite to ensure new code changes do not break their display.
Monitoring: After deployment, implement monitoring to track loading or display errors of banners in production for different locales.

How to test the display of banners on the website if they can vary depending on locales?