export interface Heading {
  /** The heading's own id, or a slug of its text when it has none. */
  id: string;
  text: string;
  /** 1–6, from the heading tag. */
  level: number;
}
 
export interface HeadingNode extends Heading {
  children: HeadingNode[];
}
 
export interface HeadingOptions {
  /** Shallowest level to collect. Defaults to 2, skipping the page title. */
  minLevel?: number;
  /** Deepest level to collect. Defaults to 3. */
  maxLevel?: number;
}
 
const HEADING_SELECTOR = 'h1, h2, h3, h4, h5, h6';
 
export function slugify(text: string): string {
  return text
    .toLowerCase()
    .trim()
    .replace(/[^a-z0-9\s-]/g, '')
    .replace(/\s+/g, '-')
    .replace(/-+/g, '-');