vanillajs-browser-helpers/insertBefore.mjs

Collection of convenience code snippets (helpers) that aims to make it a little easier to work with vanilla JS in the browser

import isString from 'vanillajs-helpers/isString';
import ensureHTML from './ensureHTML';
import inDOM from './inDOM';
import isDOMElement from './isDOMElement';
/**
 * Inserts DOM element or plain HTML before a given DOM element
 *
 * @param elm - The DOM element to insert elements before
 * @param insertElm - DOM element or HTML (or selector) to insert
 * @return The inserted element
 */
export default function insertBefore(elm, insertElm) {
    if (!inDOM(elm) || isDOMElement(elm, 'html')) {
        return null;
    }
    if (isString(insertElm)) {
        elm.insertAdjacentHTML('beforebegin', ensureHTML(insertElm));
    }
    else {
        elm.insertAdjacentElement('beforebegin', insertElm);
    }
    return elm.previousElementSibling;
}