Expose Svelte AST node types from `svelte/compiler` to public

[xeho91]

Describe the problem

As per thread on Discord.

I was working on addon for Storybook - @storybook/addon-svelte-csf. It uses svelte/compiler to extract Svelte AST nodes and analyss them for further code transformation.

Then I upgraded Svelte version. And I have noticed that since this release svelte@5.0.0-next.165 AST nodes from svelte/compiler are no longer exposed to public.

Such as:

• Component (AST version)
• Root
• SnippetBlock
• SvelteNode
• ... etc.

Possibly related PR: Rich-Harris/dts-buddy#82

Describe the proposed solution

I would like to be able to access those Svelte AST nodes, so I can have a better typings experience on those AST data structures.

Importance

would make my life easier

[benmccann]

We also need need this to get SvelteKit passing against the ecosystem CI since enhanced-img uses things like TemplateNode, BaseDirective, Attribute, and SpreadAttribute

https://github.com/sveltejs/kit/blob/43544107269013e8b5160d268da25f1e003b6f6f/packages/enhanced-img/src/preprocessor.js#L44
https://github.com/sveltejs/kit/blob/43544107269013e8b5160d268da25f1e003b6f6f/packages/enhanced-img/src/preprocessor.js#L216

[dummdidumm]

If we expose them again I'd like us to make sure somehow to not expose the internal properties of the AST nodes (for example metadata)

[huntabyte]

Hey @dummdidumm, is it just the metadata that needs to be omitted from the public interfaces or is there more? Not having these types is blocking us on a couple of things, so we are willing to attempt a PR with some guidance.

I imagine the desire is to incorporate this into the build script rather than just exporting with Omit right?

[dummdidumm]

Yeah metadata is basically all that needs to be removed (and if there's a parent property, then that, too).
I have no opinion at this time how it should be accomplished, as long as it's low maintenance, stable and relatively straightforward

[vnphanquang]

@huntabyte there was some additional discussion in the original Discord thread FYI: https://discord.com/channels/457912077277855764/1258093339232702556