import { Resolvable } from './types'

/**
 * Returns a promise that will be resolved to `undefined` after given `ms` milliseconds.
 * @param ms Time delay in milliseconds.
 */
export async function delay (ms: number): Promise<undefined>

/**
 * Returns a promise that will first resolve the `value`, then wait for given `ms` milliseconds
 * before returning the resolved value.
 * @param ms Time delay in milliseconds.
 * @param value Value to be resolved to or a promise-like object to be fulfilled.
 */
export async function delay<T> (ms: number, value: Resolvable<T>): Promise<T>

export async function delay<T> (ms: number, value?: Resolvable<T>): Promise<T | undefined> {
  const result = await value
  // eslint-disable-next-line @typescript-eslint/return-await
  return new Promise(resolve => setTimeout(resolve, ms, result))
}