How to tell if user agent Shadow Dom is open or closed?

Question

I have the following typical shadow dom html code:

<input is="text-input" class="input-element style-scope paper-input" 
autocomplete="off" placeholder="" autocapitalize="none" autocorrect="off" 
aria-describedby="" aria-labelledby="paper-input-label-22" id="input-22" 
tabindex="0">
   #shadow-root (user-agent)
   <div id="inner-editor">test</div>
</input>

I am using Selenium to try to get the text inside the of the shadow root, but it always returns null, I know the differences between open vs closed shadow DOM, and the open version of Shadow dom always displays as #shadow-root (open) in my Devtool, so I am wondering how can I tell if this user-agent shadow dom is open or closed?

Edit: I am using JS and my code look like this:

driver.executeScript("return 
    arguments[0].shadowRoot",driver.findElement(webdriver.By.css("#input-
    22"))).then(function(text) { text.getText()});

text come back as null.

Answer 1

You can tell by seeing if the innerHTML of the root element is empty or not, see this example

import selenium
from selenium import webdriver
driver = webdriver.Chrome()
from bs4 import BeautifulSoup


def expand_shadow_element(element):
  shadow_root = driver.execute_script('return arguments[0].shadowRoot', element)
  return shadow_root

driver.get("chrome://settings")
root1 = driver.find_element_by_tag_name('settings-ui')

html_of_interest=driver.execute_script('return arguments[0].innerHTML',root1)
sel_soup=BeautifulSoup(html_of_interest, 'html.parser')
sel_soup# empty root not expande

shadow_root1 = expand_shadow_element(root1)

html_of_interest=driver.execute_script('return arguments[0].innerHTML',shadow_root1)
sel_soup=BeautifulSoup(html_of_interest, 'html.parser')
sel_soup

Answer 2

As per @FlorentB. suggests,

driver.findElement(By.css("#input-22")).getAttribute("value"‌​) 

will return the text value of the user agent shadow root.