onEvent throws on HTMLElement instances that are not elements

[matthewp]

For example:

let el = document.createElement('div');

canReflect.onEvent(el.__proto__, "foo", function(){});

This is because el.__proto__ is not the actual element. I'm looking for a way to detect this.

[matthewp]

I think the mechanism the DOM uses here is an internal slot that JavaScript doesn't have access to. So there's likely no way to detect that the addEventListener method can be called. try/catch might be the only option.

[chasenlehara]

@matthewp Was this fixed/worked-around by canjs/can-observable-mixin#94?

[matthewp]

It was worked around, not sure if this issue is still valid or not, but I don't need it any more.