On 08/13/2018 12:25 PM, David Burns wrote:
> Do we have sufficient tests
There are some tests, but as always, not enough. And there are areas which are not spec'ed, like
dir-attribute handling on HTML elements with Shadow DOM and session history of iframes which are in shadow DOM.
> for this to guarantee webcompat and interop
> with other browsers?CustomElements is easier, since it doesn't really change much, just adds a way to add couple of callbacks to user defined elements.
And the behavior of those callbacks is somewhat easy to test.
Shadow DOM is trickier, since the specs aren't always quite up-to-date, or leave things undefined.
Also, in general web components are relatively rarely used feature. Google has been a big user, but it relies on
v0 implementations, meaning basically Blink, and uses polyfills with other browsers.
So, there is definitely some risk breaking web sites, but there isn't too much we can do other than trying to ship.