Using Google Analytics in React Redux

googleAnalyticsUtils.js

/* 
  Getting Google Analytics ID from environment variable GA_ID 
  This should be set on the form UA-8401XXXX-X and can be set by:
  
  1) in package.json under "scripts": {
    "start": "GA_ID=UA-8401XXXX-X node server.js"
  } 
  
  2) In webpack, under plugins:
    new webpack.EnvironmentPlugin([ 'API_URL', 'GA_ID' ])
  
  * Remember to call analyticsInit() once when application is initialized (e.g. in your index.js)
 */

export function analyticsInit() {
    if (window.ga !== undefined) {
        return;
    }
    let gaId = process.env.GA_ID;
    if (!gaId) {
        throw 'Exception: GA_ID not found as an environment variable';
    }

    /* eslint-disable */
    (function (i, s, o, g, r, a, m) {
        i['GoogleAnalyticsObject'] = r;
        i[r] = i[r] || function () {
                (i[r].q = i[r].q || []).push(arguments)
            }, i[r].l = 1 * new Date();
        a = s.createElement(o),
            m = s.getElementsByTagName(o)[0];
        a.async = 1;
        a.src = g;
        m.parentNode.insertBefore(a, m)
    })(window, document, 'script', 'https://www.google-analytics.com/analytics.js', 'ga');
    /* eslint-enable */

    window.ga('create', gaId, 'auto');
    window.ga('set', 'anonymizeIp', true);
}

export function registerPageView(title) {
    window.ga('send', {
        hitType: 'pageview',
        title: title
    });
}

export function sendCustomEvent(category, action, label, value=1) {
   window.ga('send', {
        hitType: 'event',
        eventCategory: category,
        eventAction: action,
        eventLabel: label,
        eventValue: value
    });
}