isPromise

Determine if a value is a Promise

Pass in a value and get a boolean telling you if the value is a Promise. This function is not “bullet proof” because determining if a value is a Promise in javascript is not “bullet proof”. The standard/recommended method is to use Promise.resolve to essentially cast any value, promise or not, into an awaited value. However, this may do in a pinch.

API

function isPromise(value: any): value is Promise<any>;

Usage

import { isPromise } from '@feedzai/js-utilities';

isPromise('hello')
// false

isPromise(['hello'])
// false

isPromise(new Promise(res => res()))
// true