[w3c/webcomponents] The comments on constructor conformance are somewhat redundant with the ES spec (#623)

Here's a quick list of some of the issues I found:

- [2.2 Requirements for custom element constructors](https://w3c.github.io/webcomponents/spec/custom/#custom-element-conformance)

    1. The first bullet is mostly redundant, since the language already does the right thing regarding `this`. All that really needs stated is that `super()` must be used without arguments. (It's not technically a function call, either.)
    2. The second bullet should just say that only the current instance may be returned from the constructor, if any value is.

- [2.5 Upgrades](https://w3c.github.io/webcomponents/spec/custom/#upgrades)

    The note right after step 8 is partially redundant and somewhat incorrect. The only way `super()` isn't called is if either 1. invocation throws or 2. something other than the current instance is returned (violating the invariants above), and this is enforced at the language level. The spec code does properly address this, though.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/623