How do I import Modernizr in React

I'm trying to detect whether the browser supports window.addEventListener in a create-react-app. I followed the instructions on the modernizr website and have created a modernizr.min.js file with only the single feature test I want. I can't import modernizr since it's not a module. The minified code is hard to read so I'm not sure where I'd modify it to make this a module.

So how do I actually use Modernizr in the javascript of react app?

Solution

Under your public/index.html just import the script directly

public/index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico" />
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"/>
    <meta name="theme-color" content="#000000" />


    ...


    <!-- add your scripts here -->
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.8.3/modernizr.min.js"></script>
    <!-- -->


    <title>React App</title>
  </head>
  <body>

And then in your code just call it directly

i.e. in App.jsx

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';

class App extends Component {
  render() {

    // add this to not trigger eslint no-undef
    /* global Modernizr */
    console.log(Modernizr);
    // do your checking with Modernizr
    if (Modernizr.awesomeNewFeature) {
      // do your stuff here
    } 

 ...

If you're using typescript, you need to declare the module/object first in the beginning of the typescript file that will use Modernizr, i.e.

declare const Modernizr:any;

or extend the Window interface, i.e.

declare global {
  interface Window {
    Modernizr:any     
  }
}

and call Modernizr under window interface like so

window.Modernizr.someFeature