I think it's worth tokenizing {{ as a single punctuation.definition.bracket.curly.begin.jsdoc (same for ending brackets), and maybe even applying specific rules when that is encountered. I believe that should allow us to maintain the invalid highlighting. Thoughts?

{{ seems to be the most common reason to split a type across lines, but I don't think it's the only one. For example a function type with many arguments or a union type with many alternatives can also get long.

/cc @Alhadis

My approach would've been to add a separate rule for multiline types, prepended to the JSDoc grammar's #type rule. Something like this:

	'type':
		'patterns': [
			{
				# {{ …Multiline type… }}
				'name': 'meta.multiline-type.jsdoc'
				'begin': '\\G\\{\\{'
				'end':   '\\}\\}|(?=\\*/)'
				'beginCaptures': 'punctuation.section.bracket.curly.begin.jsdoc'
				'endCaptures':   'punctuation.section.bracket.curly.end.jsdoc'
				'patterns': [ '…etc…' ]
			}
			{
				# {unclosed
				'match': '\\G{(?:[^}*]|\\*[^/}])+$'
				'name': 'invalid.illegal.type.jsdoc'

Dunno exactly what patterns should go in the above example's patterns array, because I've never heard of multiline types until now.

But this approach, while more work, would allow us to keep both the existing error-highlights, and multiline type-definitions.

A multi line jsdoc tag is just one that has the 2nd bracket on another line. Often it will start with '{{', but not always. The only way to tell if you've really got an invalid tag is to see if you get the */ before the closing '}'. But the grammar syntax doesn't have any way to do that, since it only does line based matching.

I'd really like to see this happen!

Is there an update on this feature?

It seems like the only thing this is waiting for is a style change from code review. Can I submit another PR with those changes to get this moving?

Apparently the previous comment is no longer accurate, as this needs to be migrated to Tree-sitter grammar to be accepted, is that correct?

Been sort of in limbo now for a few months where I have a feature that works, but without the syntax highlighting to go along with it.... is there help needed to get this resolved?