fix querySelector typings

[k1r0s]

No description provided.

[HolgerJeromin]

Why is that PR needed?
document.querySelector("svg")
returns the first SVGSVGElement of the document. This is not an instance of HTMLElement.

[k1r0s]

This method is overloaded, other elements can be retrieved with that method, not only SVG instances. My PR fix wrong typings when retriving other elements such as <div>, <span> .. whatever. Basically typings retrieve the wrong Type which missmatch with the retrieved runtime instance.

[mhegazy]

This method is overloaded, other elements can be retrieved with that method, not only SVG instances.

but you removed the generic one that was a catch-all for both HTMLElement and SVGElement.

I am not sure i understand the issue, can you elaborate on what this change achieves?

Also for future references, please file a bug under https://github.com/Microsoft/TypeScript/issues first.

[k1r0s]

Problem is that Element doesn't contain some of properties of HTMLElement, say style for instance. I was wondering how to achieve this. I wasn't aware of SVGElement.

Any comments? maybe problem is on Element interface :\

[saschanaz]

You can do querySelectorAll<HTMLElement>(".if .you .need").

[k1r0s]

IMO using generics isn't a good solution.

[k1r0s]

By the way HTMLElement as a generic doesn't work either bcoz you have to specificly say what type you expect

[k1r0s]

I just checked that both HTMLElement and SVGSVGElement have an style property which should be and abstract one on Element, which now doesn't exist.

The real problem is on Element class

[k1r0s]

Maybe I should close this PR and create another

$ inputfiles/addedTypes.json

    {
        "kind": "property",
        "interface": "Element",
        "name": "style",
        "type": "CSSStyleDeclaration"
    },

[HolgerJeromin]

@k1r0s Element is no TypeScript invention!
It is defined in DOM.
You see Element as equivalent to HTMLElement | SVGElement which is the reality for current Browsers, but not according to the standard.

[k1r0s]

@HolgerJeromin I get your point.

Because generics aren't working with that signature

The only workarround is to use a Type alias. document.querySelector(".hello") as HTMLElement

And isn't enough for me

[HolgerJeromin]

@k1r0s
document.querySelector<HTMLElement>(".hello")
is better than the type assertion.

[k1r0s]

@HolgerJeromin try it by yourself. Isn't working because you have this signature:

querySelector<K extends keyof ElementTagNameMap>(selectors: K): ElementTagNameMap[K] | null

[HolgerJeromin]

@k1r0s I did with ts2.6.3 with strictNullCheck active

let hello = document.querySelector<HTMLElement>(".hello");
hello is HTMLElement|null and transpiled JS is
var hello = document.querySelector(".hello");

[k1r0s]

yep @HolgerJeromin didn't try latest version. Thanks

[HolgerJeromin]

@k1r0s This is new with 2.6

[k1r0s]

very nice. Indeed!