toElement missing from MouseEvent in v3.6-beta/dev

[bre1470]

TypeScript Version: 3.6.0-dev.20190807

Search Terms: super parent property , super parent properties

Code

// A *self-contained* demonstration of the problem follows...
// Test this by running `tsc` on the command-line, rather than through another build tool such as Gulp, Webpack, etc.
interface Obj extends PointerEvent {
}
let o: Obj;
if (o && (o.relatedTarget || o.toElement)) {
    console.log(':)');
}

Expected behavior:
Inherited toElement from MouseEvent should be recognized like relatedTarget.

Actual behavior:
Error: Property 'toElement' does not exist on type 'Obj'.

Playground Link:
Lacking v3.6.

Related Issues:
Unknown

[sandersn]

@bre1470 can you explain how these are unstable? Do they vary over time as you interact with them in the editor?

(I hope they are just inconsistent, because it's usually a simpler bug in that case.)

[sandersn]

@bre1470 I can't find toElement anywhere in the PointerEvent class hierarchy. It doesn't even show up in lib.dom.d.ts. Was it there on an older version of Typescript?

[sandersn]

Looks like toElement is an old IE property. lib.dom.d.ts doesn't include these anymore, so you may need a shim to provide them (or cast to any if you're just doing feature detection).

[bre1470]

Thanks for the help! It was part of previous declarations (though with deprecated flag) and when I checked the declaration in the editor, it was still present - but this was pointing to editors declaration (3.5.1), what I obviously missed. Sorry for the false alarm.

[sod]

Chrome implements it for mouseenter & mouseleave events. It contains the element the cursor hit when the event emits. In case there is a mouseleave because the user enters a native element (like autosuggest dropdown) it contains null.

In firefox it's undefined.