/**
 * Plugin to automatically add `target` and `rel` attributes to external links.
 *
 * @type {import('unified').Plugin<[Options?] | Array<void>, Root>}
 */
export default function rehypeExternalLinks(
  options?: void | Options | undefined
):
  | void
  | import('unified').Transformer<import('hast').Root, import('hast').Root>
export type Root = import('hast').Root
export type Properties = import('hast').Properties
export type Element = import('hast').Element
export type ElementChild = Element['children'][number]
export type Target = '_self' | '_blank' | '_parent' | '_top'
export type Rel = Array<string> | string
export type Protocols = Array<string>
export type Content = ElementChild | Array<ElementChild>
export type ContentProperties = Properties
export type TargetCallback = (node: Element) => Target | null | undefined
export type RelCallback = (node: Element) => Rel | null | undefined
export type ProtocolsCallback = (node: Element) => Protocols | null | undefined
export type ContentCallback = (node: Element) => Content | null | undefined
export type ContentPropertiesCallback = (
  node: Element
) => Properties | null | undefined
/**
 * Configuration.
 */
export type Options = {
  /**
   * How to display referenced documents (`string?`: `_self`, `_blank`,
   * `_parent`, or `_top`, default: `_blank`).
   * The default (nothing) is to not set `target`s on links.
   */
  target?: Target | TargetCallback | undefined
  /**
   * Link types to hint about the referenced documents.
   * Pass an empty array (`[]`) to not set `rel`s on links.
   *
   * **Note**: when using a `target`, add `noopener` and `noreferrer` to avoid
   * exploitation of the `window.opener` API.
   */
  rel?: Rel | RelCallback | undefined
  /**
   * Protocols to check, such as `mailto` or `tel`.
   */
  protocols?: Protocols | ProtocolsCallback | undefined
  /**
   * hast content to insert at the end of external links.
   * Will be inserted in a `<span>` element.
   *
   * Useful for improving accessibility by giving users advanced warning when
   * opening a new window.
   */
  content?: Content | ContentCallback | undefined
  /**
   * hast properties to add to the `span` wrapping `content`, when given.
   */
  contentProperties?:
    | import('hast').Properties
    | ContentPropertiesCallback
    | undefined
}