30-seconds-of-code/snippets/isAsyncFunction.md

title, tags, expertise, firstSeen, lastUpdated

title	tags	expertise	firstSeen	lastUpdated
Value is async function	type,function	intermediate	2020-08-07T15:41:55+03:00	2020-10-20T11:21:07+03:00

Checks if the given argument is an async function.

• Use Object.prototype.toString() and Function.prototype.call() and check if the result is '[object AsyncFunction]'.

const isAsyncFunction = val =>
  Object.prototype.toString.call(val) === '[object AsyncFunction]';

isAsyncFunction(function() {}); // false
isAsyncFunction(async function() {}); // true