Alternatively, you can manually trigger a real scroll event as following:
el.dispatchEvent(new CustomEvent('scroll'))
Which feels a bit less of a hack (and more performant) than dual scrolling by +1 and -1 pixels…
This should run any piece of code listening for a scroll event.
Edit: To support IE11 or other legacy browser, consider using a CustomEvent polyfill such as mdn-polyfills