document.all is undefined

[omarsy]

Basic info:

• Node.js version: v12.16.1
• jsdom version:16.4.0

Minimal reproduction case

When I try to get document.all in jsdom that returns me 'undefined' or in the browser it returns me HTMLAllCollection

The link to reproduce the issue: https://repl.it/@omarsy1/BothRosyScience#index.js

[ExE-Boss]

Implementing this correctly will be difficult, as it will require a native Node module to create a Proxy with the [[IsHTMLDDA]] internal slot.

It will also require a way to specify custom Proxy constructors in WebIDL2JS.