For future me

logAllEventsForEl.js

const logAllEventsForEl = (el) => {
    Object.keys(el.__proto__.__proto__)
        .reduce((eventNames, key) => {
            if (key.startsWith('on')) {
                return [...eventNames, key.substr(2)]
            }
            return eventNames
        }, [])
        .map(eventName => {
            el.addEventListener(eventName, event => console.log(event.type))
        })
}