index.html

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
            <title>Loading ...</title>
            <script>
                if (typeof process === "undefined") { // running in the browser, not Electron!
                    window.process = { env: { HOT: true } };
                    console.log("Running in development mode, in-browser");
                    function require(n) {
                        function stub() {
                            console.log("Called function `" + arguments.callee.name + ' ` with data: ', arguments);
                            return "";
                        }
                        console.log("Required `" + n + "`");
                        if (n === 'querystring') {
                            return { parse: stub }
                        }
                        if (n === 'electron') {
                            return { ipcRenderer: { send: stub, on: stub } }
                        }
                    }
                }
            </script>
    </head>
    <body>
        <div id="root"></div>
        <div id="full"></div>
        <script>
            (function() {
                const script = document.createElement('script');
                script.src = (process.env.HOT) ? 'http://localhost:3000/dist/bundle.js' : 'bundle.js';
                document.write(script.outerHTML);
            }());
        </script>
    </body>
</html>