HTMLSelectElement.options

[cevek]

interface HTMLSelectElement {
    options: HTMLSelectElement; // should be HTMLCollection

[robfe]

Is there any special reason why this one-line fix keeps getting pushed back? https://github.com/Microsoft/TypeScript/blob/master/src/lib/dom.generated.d.ts#L6078

If it's just a matter of priorities I'd love to help out. This one is annoying me since there's no clean way to replace the interface property

[mhegazy]

@zhengbli can you take a look.

[RyanCavanaugh]

@robfe it's a prioritization thing. FWIW we're always accepting PRs for lib.d.ts fixes (or anything else that's very low-risk, e.g. wiki edits, comments / formatting improvements, etc).

[robfe]

I've just noticed that IE 11 itself considers options to be a reference to the select element

var s = document.createElement("select");
console.log(s.options === s); // true in IE 11, false in other browsers

In the older spec options is a HTMLCollection: http://www.w3.org/TR/REC-DOM-Level-1/level-one-html.html#ID-94282980

readonly attribute HTMLCollection options;

But as per http://www.w3.org/TR/html5/forms.html#dom-select-options it's an HTMLOptionsCollection

The options IDL attribute must return an HTMLOptionsCollection rooted at the select node, whose filter matches the elements in the list of options.

where HTMLOptionsCollection is:

interface HTMLOptionsCollection : HTMLCollection {
  // inherits item()
           attribute unsigned long length; // shadows inherited length
  legacycaller HTMLOptionElement? (DOMString name);
  setter creator void (unsigned long index, HTMLOptionElement? option);
  void add((HTMLOptionElement or HTMLOptGroupElement) element, optional (HTMLElement or long)? before = null);
  void remove(long index);
           attribute long selectedIndex;
};

I'm keen to submit a fix for this, but what's your preference @mhegazy @RyanCavanaugh @zhengbli ?

1. leave it as is (with the interface matching IE11's implementation)?
2. a one line PR that changes it to HTMLCollection?
3. a slightly larger PR that adds the HTMLOptionsCollection interface?

[zhengbli]

Confirmed that in Edge the HTMLSelectElement.options is still a reference of itself, the same with IE 11. I suggest to make the type of HTMLSelectElement.options HTMLSelectElement | HTMLCollection to avoid assignability problems.

[mhegazy]

that does not help much. now the users who expect it to be HTMLSelectElement do not get that, nor the ones who want it to be HTMLCollection. both groups will have to cast.

[zhengbli]

@mhegazy tested on the latest Edge that HTMLSelectElement.options became HTMLCollection, which is consistent with Chrome and Firefox. It should be OK to use it instead.

[mhegazy]

👍