how to know the value of cookie in javascript in nodejs code example

Example: get cookie value in javascript

const getCookie = (cookie_name) =>{
  // Construct a RegExp object as to include the variable name
  const re = new RegExp(`(?<=${cookie_name}=)[^;]*`);
  try{
    return document.cookie.match(re)[0];	// Will raise TypeError if cookie is not found
  }catch{
    return "this-cookie-doesn't-exist";
  }
}

getCookie('csrftoken')	// ADZlxZaPSa6k4oyelVBa5iWTtLJW8P3Jf7nhW90L2ZWc5Zcq2vKLO1RRFbaKco3C
getCookie('_non_existent') // this-cookie-doesn't-exist