Check if a value is a function on Javascript

const isFunction = (o) => ['[object Function]', '[object GeneratorFunction]', '[object AsyncFunction]', '[object Promise]'].includes(Object.prototype.toString.call(o));

// Return true
isFunction(function () {});

// Return true
const f = () => { return 'hello'; };
isFunction(f);

// Return false
const n = 10;
isFunction(n);