ServiceWorker script evaluation failed

[pedrogscruz]

Bug Report or Feature Request (mark with an x)

- [x] bug report -> please search issues before submitting
- [ ] feature request

Versions.

browser: chrome
browser version: 75.0.3770.100
operating system: Linux Mint
webpack version: 4.39.1

Repro steps.

I just followed the steps of README.md. I even insert the sw.js from the example to test.

index.tsx

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { BrowserRouter } from "react-router-dom";
import { Route } from "react-router-dom";

import { initializeFirebase } from 'push-notification';
import App from "components/app/App";
import store from "redux/store";
// @ts-ignore
import runtime from 'serviceworker-webpack-plugin/lib/runtime';

import "index.css";

runtime.register();
initializeFirebase();

ReactDOM.render(
    <BrowserRouter>
        <Provider store={store}>
            <Route component={App} />
        </Provider>
    </BrowserRouter>,
    document.getElementById('root')
);

webpack

plugins: [
     ...
     new ServiceWorkerWebpackPlugin({ entry: path.resolve(__dirname, 'src')+'/sw.js' })
]

Desired or expected functionality

Don't get the errors
"window is not defined" in browser.js inside process lib.
"Failed to register a ServiceWorker: ServiceWorker script evaluation failed".