type CB<T> = (...args: [Error] | [null, T]) => void

declare module 'atomic-file-rw' {
  export function readFile(path: string, encoding: string, cb: CB<string>): void;
  export function writeFile(path: string, data: string, encoding: string, cb: CB<string>): void;
  export function deleteFile(path: string, cb: CB<null>): void;
}