How to fix “TypeError: Cannot read property 'inherits' of undefined” in React project?

Question

I working on React project. I'm trying to use the npm package async-polling ( https://www.npmjs.com/package/async-polling ), that wants to use the inherits class of the node-utils ; Internally the library has the following lines:

var inherits = hasWindow ? window.nodeUtil.inherits : require('util').inherits;
var EventEmitter = hasWindow ? window.nodeEventEmitter : require('events').EventEmitter;

Of course since the app is running in the browser, hasWindow is true. But there is no nodeUtil or nodeEventEmitter . Therefore I get the error:

TypeError: Cannot read property 'inherits' of undefined

Then I tried adding the util and events package and doing this:

window.nodeUtil = require('util');
window.nodeEventEmitter = require('events');

But I got this error:

TypeError: AsyncPolling is not a constructor

Anther fork was able to fix this issue, but I want to try and stick with the original package, is there a way to fix the issue?

Answer 1

As best I can tell async-polling is an old, unmaintained module that you're better off avoiding. You're running into problems because the module is expecting the presence of two global variables nodeUtil and nodeEventEmitter . It looks like the package is better suited to a node environment and is relying on polyfills in the browser.

I'd suggest finding a more up-to-date package or simply using setInterval to poll.

const intervalInMilliseconds = 5000;
const timerId = setInterval(() => {
  if (/* some condition is met */) {
    clearInterval(timerId);
  } else {
    // do stuff
  }
}, intervalInMilliseconds);