From the Web IDL spec: https://heycam.github.io/webidl/#idl-undefined
[...]
undefined constant values in IDL are represented with the `undefined`
token.
[...]
Note: This value was previously spelled `void`, and more limited in how
it was allowed to be used.
Specification: https://dom.spec.whatwg.org/#concept-event-dispatch
This also introduces shadow roots due to it being a requirement of
the event dispatcher.
However, it does not introduce the full shadow DOM, that can be
left for future work.
This changes some event dispatches which require certain attributes
to be initialised to a value.
Reading the property has a few warts (see FIXMEs in the included
tests), but with this the timestamps on http://45.33.8.238/
get localized :^)
Since the Date() constructor currently ignores all arguments,
they don't get localized correctly but are all set to the current
time, but hey, it's still progress from a certain point of view.
...{All} to ParentNode. Exposes createDocumentFragment and
createComment on Document. Stubs out the document.body setter.
Also adds ParentNode back :^).
HTMLElement is the only interface that includes ElementContentEditable
in the HTML specification. This makes sense, as Element is also a base
class for elements in other specifications such as SVG,
which definitely shouldn't be editable.
Also adds a test for the attribute based on what Andreas did in the
video that added it.
