Description
I just merged a PR (w3c/css-houdini-drafts#980) specifying how to serialize an @property rule. I wasn't sure whether it should all be serialized on one line (as the PR specified, and now in the draft), or if they should be indented on a newline, so I went looking for precedents, and it doesn't appear we have any.
Afaict, no spec defines how to serialize rules at all: not CSSOM, nor any spec that defines its own at-rules, like Conditional or Animations.
I presume we want to specify this so we can be consistent, and can test rule serialization? How should it work? Where should such a definition live - individual specs, or in CSSOM, or general rules in CSSOM with explicit hooks that individual specs have to define for serialization of preludes and which descriptors to include?