export type Deferred<T> = Promise<T> & {
  resolve: (value?: T | PromiseLike<T>) => void
  reject: (reason?: any) => void
}

export function deferred<T>(): Deferred<T> {
  let methods
  const promise = new Promise<T>((resolve, reject): void => {
    methods = { resolve, reject }
  })
  return Object.assign(promise, methods) as Deferred<T>
}