/**
 * Create an assertion from `check`.
 *
 * @param {Check} [check]
 *   Check.
 * @returns {Assert}
 *   Assertion.
 */
export function convert(check?: Check): Assert
/**
 * Check if `file` is a specific file.
 *
 * Converts `check` to an assertion and calls that assertion with `file`.
 * If you’re doing a lot of checks, use `convert`.
 *
 * @param {unknown} file
 *   File to check (typically `VFile`).
 * @param {Check} [check]
 *   Check.
 * @returns {boolean}
 *   Whether `file` is a file and matches `check`.
 */
export function is(file: unknown, check?: Check): boolean
export type VFile = import('vfile').VFile
/**
 * Check that a file is a `vfile` and passes a test.
 */
export type Assert = (file?: unknown) => boolean
/**
 * Check if a file passes a custom test.
 */
export type CheckFile = (file: VFile) => boolean | null | undefined | void
/**
 * Object describing fields to values.
 *
 * Each key is a field in the file and each value is:
 *
 * *   `boolean` — whether the field exists or not
 * *   `string` — exact value of that field
 * *   `object` — start (prefix) and/or end (suffix) of the field
 */
export type CheckFields = Record<
  string,
  FieldPartial | boolean | string | null | undefined
>
export type CheckItem = CheckFields | CheckFile | string | null | undefined
/**
 * Different ways to check for a specific file.
 *
 * *   if check is a glob string, checks if that glob matches `file.path`
 * *   if check is a normal string, checks if that is `file.basename` or
 *  `file.extname`
 * *   if check is a function, checks whether that yields `true` when called
 * *   if check is a normal object, checks if the given file matches the
 *  `Spec`
 * *   if check is an array, all tests in it must pass
 */
export type Check = Array<CheckItem> | CheckItem
/**
 * Check the prefix and/or suffix of a field.
 */
export type FieldPartial = {
  /**
   * Prefix.
   */
  prefix?: string | null | undefined
  /**
   * Suffix.
   */
  suffix?: string | null | undefined
}