Check if class exists somewhere in parent - vanilla JS

You'll have to do it recursively :

// returns true if the element or one of its parents has the class classname
function hasSomeParentTheClass(element, classname) {
    if (element.className.split(' ').indexOf(classname)>=0) return true;
    return element.parentNode && hasSomeParentTheClass(element.parentNode, classname);
}

Demonstration (open the console to see true)

You can use the closest() method of Element that traverses parents (heading toward the document root) of the Element until it finds a node that matches the provided selectorString. Will return itself or the matching ancestor. If no such element exists, it returns null.

You can convert the returned value into boolean

const el = document.getElementById('div-03');

const r1 = el.closest("#div-02");  
console.log(Boolean(r1));
// returns the element with the id=div-02

const r2 = el.closest("#div-not-exists");
console.log(Boolean(r2));

<article>
  <div id="div-01">Here is div-01
    <div id="div-02">Here is div-02
      <div id="div-03">Here is div-03</div>
    </div>
  </div>
</article>

You can use some and contains to achieve the result:

function hasParentWithMatchingSelector (target, selector) {
  return [...document.querySelectorAll(selector)].some(el =>
    el !== target && el.contains(target)
  )
}

// usage
hasParentWithMatchingSelector(myElement, '.some-class-name');