/**
 * @callback Exit
 *   Exit function.
 * @returns {void}
 */
/**
 * @callback Enter
 *   Enter function.
 * @returns {Exit}
 *   Exit function.
 */
/**
 * Create a toggle, which when entering toggles `key` on `ctx` (or `this`, if
 * `ctx` is not given) to `!initial`, and when exiting, sets `key` on the
 * context back to the value it had before entering.
 *
 * @param {string} key
 *   Key to toggle
 * @param {boolean} state
 *   Default state.
 * @param {Record<string|number|symbol, unknown>} [ctx]
 *   Record to toggle on (default: `this` of `enter`).
 * @returns {Enter}
 *   Enter function.
 */
export function stateToggle(
  key: string,
  state: boolean,
  ctx?: Record<string | number | symbol, unknown> | undefined
): Enter
/**
 * Exit function.
 */
export type Exit = () => void
/**
 * Enter function.
 */
export type Enter = () => Exit