Svelte Grammar is outdated for usage with Typescript

[sebastinez]

Currently linguist uses https://github.com/umanghome/svelte-atom as grammar for svelte.
The issue is that Svelte has a somewhat new typescript directive lang="ts" in the script tag, which can create issues when rendering.

See here https://github.com/radicle-dev/radicle-interface/blob/master/src/Authorship.svelte

The correct way to highlight this should be:

I would suggest while waiting for the tree-sitter-svelte grammar to be solid, to have a new updated fork for the pretty lights svelte grammar.

I have updated the grammar on a fork of mine in the meantime https://github.com/sebastinez/svelte-atom/tree/sebastinez/add-lang-ts

[lildude]

We can certainly switch to using your fork, but before we do, you might want to check on the progress of the https://github.com/sveltejs/svelte-atom grammar. We switched to it but had to revert as it broke the syntax highlighting of Svelte code between <(script|style|template)> tags. See #6164 for the full discussion and history and upstream issue links.

[sebastinez]

Hey @lildude,

Thanks for your quick response! I already went down this rabbit hole 😅
It seems that the sveltejs/svelte-atom didn't had any improvements in the last months, since you switched to it and then reverted back from it.
Regarding the fix I have in my fork over the one from @umanghome it seems that this is already addressed in the svelte-atom repo https://github.com/sveltejs/svelte-atom/blob/865a55f096ed0d60a316234f55f6f356abd5cd1f/grammars/svelte.cson#L42

Have to compile the svelte-atom grammar to json to see what's still broken there..

[lildude]

Regarding the fix I have in my fork over the one from @umanghome it seems that this is already addressed in the svelte-atom repo https://github.com/sveltejs/svelte-atom/blob/865a55f096ed0d60a316234f55f6f356abd5cd1f/grammars/svelte.cson#L42

Have to compile the svelte-atom grammar to json to see what's still broken there..

No need. Linguist can use CSON grammars. The problem is the fix you've pointed to won't work until the grammar is updated to address the $ naming problem identified in #6164 (comment)

[sebastinez]

Ok from what I can see, the issue that started the entire discussion you pointed at is here sveltejs/svelte-atom#20 and has to do with the template tag not being handled correctly, which ended in reverting the usage of the sveltejs/svelte-atom repo.

So AFAIC see the umanghome/svelte-atom repo has this issue handled, but since it's not maintained lost some of the newer svelte features.
So I'll create a PR to use my fork of the umanghome/svelte-atom repo where the newest features are implemented and the $ naming problem isn't an issue, since we declare everything explicitly.

If at any point in time the svelte treesitter grammar improves enough to be used instead this should be done of course.

[sebastinez]

Ok I wrote a small PR that moves the Svelte Grammar definition to a maintained fork
#6216