Value is async function

Angelos Chalaris · JavaScript, Type, Function · Oct 20, 2020

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

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