CommonJS Illegal invocation error when calling function on module.exports

Question

Doing this works fine:

var requestAnimationFrame = 
    window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame;

function _test() {
    console.log('hello from test');
}

requestAnimationFrame(_test);

However moving this to another file and exporting it using CommonJS/webpack results in:

Uncaught TypeError: Illegal invocation

(like so:)

module.exports.requestAnimationFrame = 
    window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame;

...

var poly = require('../utils/polyfills');
poly.requestAnimationFrame(_test);

It's probably super obvious but in my mind I don't get why that wouldn't work :/

Answer 1

I found the answer here: Why are certain function calls termed "illegal invocations" in JavaScript?

It seems some native functions depend on context, so to fix this I bind to window:

module.exports.requestAnimationFrame = 
    (window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame).bind(window);