DomEvent.off() not working correctly when called with one parameter

How to reproduce

• Leaflet version I’m using: 1.3.0
• Browser (with version) I’m using: Chome 63.0.3239.132
• OS/Platform (with version) I’m using: Linux
• Assing event handler on an element using DomEvent.on(element, ‘eventType’, callback)
• Remove all event handlers from element using DomEvent.off(element)
• Expect that after firing event, the callback will not be executed. (It is not working)

Minimal example reproducing the issue

var div = document.getElementById('leaflet');
var eventHandler = function(){
  alert('Handler fired!');
}
L.DomEvent.on(div, 'click', eventHandler);
L.DomEvent.off(div);
//now manually click on div element -> alert is shown

https://plnkr.co/edit/yQ1GzAFD9oDNqnV0Nhok?p=preview

Possible solution

I think that problem is in DomEvent.js

export function off(obj, types, fn, context) {
(...)
	} else {
		for (var j in obj[eventsKey]) {
                        //this does nothing cause j variable is not parsed
			removeOne(obj, j, obj[eventsKey][j]);
		}
		delete obj[eventsKey];
	}
(...)

In this case j is a key which isn’t event type. It is a event handler id (e.g. resize37_35) In order to fix it, j= j.replace(/[^a-z]/g, '') or something similar.

[IvanSanchez]

~~~I think you should use `map.on(...)` instead of `L.DomEvent.on(map, ...)`. Or, if deemed necessary, `L.ComEvent.on(map.getContainer(), ... )`. Note how, according to the documentation, the return type of `getContainer` is an `HTMLElement`.~~~

[johnd0e]

the docs no longer claim this is possible.

But our code still has some code trying to handle this case: https://github.com/Leaflet/Leaflet/blob/ec35ab52f66c191f7c855583354722c40dcdf239/src/dom/DomEvent.js#L30-L36

As mentioned by @IvanSanchez this code fails. So we need either to remove it completely, or fix it (which is easy too).