refactor(types): use dts-buddy to generate types with map

[dominikg]

and cleanup type definitions and tsconfig

This introduces a types:generate script that has to be called every time you change a type to update types/index.d.ts which is commited.

Having the generated file in the repo ensures that we are able to review changes in public types and can prevent unintended drift or breaking changes

[dominikg]

@Rich-Harris in #658 you did an export of index.js from a d.ts files which I didn't use here. Was that something that has changed in dts-buddy or is this one here holding it wrong?

[dominikg]

example of the script that validates types are in sync https://github.com/sveltejs/vite-plugin-svelte/actions/runs/6207076288/job/16851955290?pr=751#step:12:18

[dominikg]

hmm, dts-buddy pulling in an older version of ts isn't optimal...

[Rich-Harris]

Bumped dts-buddy, so that it now consumes TypeScript as a peer dependency.

in #658 you did an export of index.js from a d.ts files which I didn't use here

The reason for that is that people should be able to do this...

import type { CompileOptions } from '@sveltejs/vite-plugin-svelte';

...which isn't possible if the index.js is the entry module, since it doesn't (can't) re-export the stuff in public.d.ts. In cases where we want to expose both types and values, but are authoring in .js with JSDoc, we need to treat the .d.ts file as the entry point and re-export the values from the real entry point.

[dominikg]

hmm, i think this works. Not for CompileOptions as that is now imported from svelte-4 and only part of the Options type of vite-plugin-svelte, but here is the type in the namespace
https://github.com/sveltejs/vite-plugin-svelte/pull/751/files#diff-3ce3450c71e77215bb00652cd1afec4105620695f279d2c142552a181c3fb877R7

and at least in my local tests import type {Options} from '@sveltejs/vite-plugin-svelte' works. (for the rare case a user needs to do it at all, usually they just do

import {svelte} from '@sveltejs/vite-plugin-svelte';
import {defineConfig} from 'vite';
export default defineConfig({
  plugins: [
    svelte({
      // yay for autocomplete
    })
  ]
})

note that in this repo the output of dts-buddy is commited, so /types/index.d.ts is what is going to get published. a mismatch is prevented by calling a script that ensures the output is in sync with the current repo content.

[bluwy]

Still not a fan of dts-buddy 😬 But I won't block the PR if you want to merge it.