luhn-generator/update/node_modules/axe-core/lib/commons/dom/idrefs.js

A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm

import getRootNode from './get-root-node';
import { tokenList } from '../../core/utils';

/**
 * Get elements referenced via a space-separated token attribute;
 * it will insert `null` for any Element that is not found
 * @method idrefs
 * @memberof axe.commons.dom
 * @instance
 * @param  {HTMLElement} node
 * @param  {String} attr The name of attribute
 * @return {Array|null} Array of elements (or `null` if not found)
 *
 * NOTE: When in a shadow DOM environment: ID refs (even for slotted content)
 * refer to the document in which the element is considered to be in the
 * "light DOM". Therefore, we use getElementById on the root node and not QSA
 * on the flattened tree to dereference idrefs.
 *
 */
function idrefs(node, attr) {
	node = node.actualNode || node;

	try {
		const doc = getRootNode(node);
		const result = [];
		let attrValue = node.getAttribute(attr);

		if (attrValue) {
			attrValue = tokenList(attrValue);
			for (let index = 0; index < attrValue.length; index++) {
				result.push(doc.getElementById(attrValue[index]));
			}
		}

		return result;
	} catch (e) {
		throw new TypeError('Cannot resolve id references for non-DOM nodes');
	}
}

export default idrefs;