Use webidl2js named/indexed properties everywhere

[domenic]

Now that we have support for named and indexed properties, we should figure out how to use them everywhere---while not regressing performance.

Existing collections implemented in jsdom, to update

• FileList
• DOMStringMap
• NodeList
• HTMLCollection
• HTMLOptionsCollection
• HTMLSelectElement
• NamedNodeMap Convert NamedNodeMap to IDL #2052
• DOMTokenList Convert DOMTokenList to IDL + related goodies #1953
• HTMLFormElement (currently doesn't do anything)
• Document (aka HTMLDocument in jsdom; currently doesn't do anything)

There's also Window, but that's a whole bunch more work, as it needs a special named properties object, and performance is likely to be even more delicate.

New collections we can now implement

• Storage, i.e. localStorage and sessionStorage: localstorage doesn't work within jsdom #1137

[Joris-van-der-Wel]

Some are marked as [OverrideBuiltins] http://www.w3.org/TR/WebIDL/#OverrideBuiltins:

• HTMLFormElement
• DOMStringMap
• Document

(but not HTMLCollection and Window).

This means that the named properties will shadow any property (e.g. toString, attributes, firstChild, proto). This will break a lot. For this to work, jsdom must only use getters/setters/methods that are not exposed (for example, everything protected by symbols).

IMO, this part of the spec is completely insane and I would rather pretend [OverrideBuiltins] does not exist. Even if the browsers all implement it this way.

[Joris-van-der-Wel]

I think it is okay to do it for DOMStringMap though, it has no default properties except for what Object provides. So it would be kinda like {}

[domenic]

Yeah, I'd be happy leaving [OverrideBuiltins] as a TODO for the far future when none of jsdom goes through the public interface of any other part of jsdom.

[domenic]

Renamed and updated OP in light of #1934!

[TimothyGu]

An update: NodeList and HTMLCollection now use webidl2js. NamedNodeMap (used for element.attributes) was moved to webidl2js, but Proxy performance was then found to be too slow for NamedNodeMap. DOMTokenList has been implemented in jsdom, but has not been transitioned yet. It's on my radar though. Additionally, DOMStringMap (used for element.dataset) and HTMLOptionsCollection (a la selectElement.options) have been implemented.

[domenic]

Thanks, updated OP further. I misremembered about NodeList.