- breaking: make TypeScript a peer dependency
- breaking: require node 18 or later
- breaking: require Svelte 4 or later (devDependencies pinned to Svelte 3 because other packages in this repo still use it. Theoretically we still support Svelte 3 with svelte-check v4 but this gives us the opportunity to adjust that later without a major)
- chore: switch from fast-glob to fdir (#2433)

closes #2397
fixes #2364

---------

Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>

- closes #2148
- fixes #1234 - due to the change of how files are resolved (breaking change)
- fixes #1976 - less options are now forced (breaking change)
- fixes #2154 (breaking change)

- use Svelte 4 as built-in version now
- add exports map
- bump vs code ls/client version to 9
- require Node 18 / VS Code 1.82 minimum
- drive-by fix of __sveltets_2_ensureComponent (the previous version didn't work after all)

requires adjustments of mapping tests and a fix in the InlayHintProvider, because more things are mappable now

#1392

This adds enhanced type checking for bindings in Svelte 5: We're not only passing the variable in, we're also assigning the value of the component property back to the variable. That way, we can catch type errors like the child binding having a wider type as the input we give it.
It's done for Svelte 5 only because it's a) easier there b) doesn't break as much code (people who upgrade can then also upgrade the types, or use type assertions in the template, which is only possible in Svelte 5).
There's one limitation: Because of how the transformation works, we cannot infer generics. In other words, we will not catch type errors for bindings that rely on a generic type. The combination of generics + bindings is probably rare enough that this is okay, and we can revisit this later to try to find a way to make it work, if it comes up.
Also note that this does not affect DOM element bindings like <input bind:value={...} />, this is only about component bindings.

Svelte files are now resolved by intercepting checks for .d.svelte.ts instead of .svelte.ts. As a consequence, we can handle sibling foo.svelte / foo.svelte.ts files and importing both. When doing import Foo from './foo.svelte this now resolves to the Svelte file (prio to #2463 it would resovle to the .svelte.ts file), and doing import Foo from './foo.svelte.js will resolve to the TS file.

… root (#2480)

part of #2479

This was missing in #2473

Possibly related to sveltejs/svelte#13039

closes #2371