DOM Comments don't align with HTML comments

[josepharhar]

In the HTML spec, it says that comments must not contain --> among other things: https://html.spec.whatwg.org/multipage/syntax.html#comments

In the DOM spec, it says that you can create a Comment with any text, no restrictions: https://dom.spec.whatwg.org/#interface-comment

This was raised in a chrome issue where someone pointed out that you can create a Comment in script which contains a -->, put other things after the -->, and reassign document.body.innerHTML = document.body.innerHTML which will make everything after the --> get parsed as actual HTML instead of comments

@mfreed7

[annevk]

It's generally true that you can create node trees that cannot be serialized or that can be serialized and then when parsed result in a different tree. This is not a unique ability of comments.

https://html.spec.whatwg.org/#serialising-html-fragments points this out in a warning.

https://html.spec.whatwg.org/#serialising-xhtml-fragments on the other hand does attempt to account for it, but I'm not sure how well tested that is.

Did you have a suggestion or do you think DOM should call this out more prominently?

[josepharhar]

It's generally true that you can create node trees that cannot be serialized or that can be serialized and then when parsed result in a different tree. This is not a unique ability of comments.

With this in mind, I think it's OK to leave things as is.