'this' reference is undefined

[GeorgeKnap]

I am using screenfull.js 4.2.0 in Angular app and I'm curious if anyone encountered my situation as I'm running out of ideas.

this is how I use this library in one of my component:

import * as screenfull from 'screenfull';
import { Screenfull } from 'screenfull';

const sf = screenfull as Screenfull;
 if (sf.enabled) {
      sf.toggle(someElement);
    }

Everything works fine when it's served for development via ng serve.
However, when built via ng build --prod I'm getting runtime error TypeError: Cannot read property 'isFullscreen' of undefined.

[1615450788]

4.0.1 is normal

[sindresorhus]

Screenfull is an object, and its methods are not individual exports, so when you try to import each method individually with import * as screenfull from 'screenfull';, you lose the this binding. The correct way to import it is import screenfull = require('screenfull');.