18F/web-design-standards

const select = require("./select");
/**
 * @name isElement
 * @desc returns whether or not the given argument is a DOM element.
 * @param {any} value
 * @return {boolean}
 */
const isElement = (value) =>
  value && typeof value === "object" && value.nodeType === 1;

/**
 * @name selectOrMatches
 * @desc selects elements from the DOM by class selector or ID selector.
 * @param {string} selector - The selector to traverse the DOM with.
 * @param {Document|HTMLElement?} context - The context to traverse the DOM
 *   in. If not provided, it defaults to the document.
 * @return {HTMLElement[]} - An array of DOM nodes or an empty array.
 */
module.exports = (selector, context) => {
  const selection = select(selector, context);
  if (typeof selector !== "string") {
    return selection;
  }

  if (isElement(context) && context.matches(selector)) {
    selection.push(context);
  }

  return selection;
};