Syntax for ignored comments

[theoephraim]

I just ran across some very unexpected behaviour around html comments in templates.
Basically if there is a comment at the root of the component (either before or after an actual node) then it treats the component as a multi-root component, which breaks things like using a template ref to get to the component's root.

There is some discussion about how to handle comments in general here, but I wanted to bring up a different related idea which might also help.

I would imagine the majority of comments in templates are simply notes for devs, and are never required or even desired in the rendered HTML. There are for sure cases where the comments are deliberate and you want them preserved, but I'd say that's the exception, not the rule.

I'm suggesting introducing some new syntax for template comments that will be totally ignored during compilation.

Pug has a similar feature with one style of comments being preserved in the rendered output:

// this comment will be preserved in rendered html
//- this comment will not!

Perhaps there is something similar we could do where we introduce a slightly modified syntax which signals to the compiler to totally drop it. Something like:

<!-- this will be preserved -->
<!--/ this will not! -->

While I'd love a more terse single line comment style in vue templates only (something like <// single line comment woohoo). I imagine getting that built into all the IDE tooling would be a considerable lift versus something that is compatible with the existing/standard HTML comments.