/**
 * Checks if the given HTML element contains the specified text or matches the regular expression.
 *
 * @param node - The HTML element to check for the presence of text.
 * @param textMatch - The text or regular expression to match within the HTML element.
 * @returns Returns one of the following:
 *   - true, if the element contains the exact text match;
 *   - RegExpMatchArray, if the element's text matches the regular expression;
 *   - null, if there is no match.
 */
export default function hasText(node: HTMLElement, textMatch: string | RegExp): true | RegExpMatchArray | null;