vite-plugin-svelte VS svelte-preprocess

Actually in more recent SvelteKit projects they use the Vite-preprocessor to handle Typescript

You can use the inspector option with vite-plug-in-svelte. Look at inspector in the docs here and you’ll see. You can click on a component and it opens where it is in your editor. https://github.com/sveltejs/vite-plugin-svelte/blob/main/docs/config.md

Please report the issue to https://github.com/sveltejs/vite-plugin-svelte if you found a problem.

Looks like you can change this in the vite-plugin-svelte options: extensions: ['.svelte'],

Note that this is still experimental. There's a bug when using it with npm, but the author aware of it.

This question gives good insight on "why vite" but the fourth question on the migration stays quite unanswered. The vite-plugin-svelte is mentioned but I'm still not sure which steps there are to take exactly. Could someone give instructions on how to migrate a project from rollup to vite?

In Vite: https://github.com/sveltejs/vite-plugin-svelte Webpack: https://github.com/sveltejs/svelte-loader

You can learn more about the official svelte-preprocess and other available config here

svelte-preprocess is responsible for processing things like TypeScript and SCSS. The svelte compiler itself is only responsible for turning the svelte file into JavaScript.

svelte-preprocess should handle scss out-of-the-box, and it’s included in SvelteKit by default if you created your project with create-svelte

// svelte.config.js import sveltePreprocess from 'svelte-preprocess' export default { // Consult https://github.com/sveltejs/svelte-preprocess // for more information about preprocessors // **here -> postcss: true** preprocess: sveltePreprocess({ postcss: true, }) }

/** @type {import('@sveltejs/kit').Config} */ const config = { // Consult https://github.com/sveltejs/svelte-preprocess // for more information about preprocessors preprocess: preprocess({ typescript: true, postcss: true, scss: { prependData: @import 'src/styles/helpers/functions.scss'; } }), kit: { paths: { assets: '', base: dev ? '' : '/route/in/website' }, trailingSlash: 'always', adapter: adapter({ pages: 'build', assets: 'build', fallback: 'index.html' }), files: { hooks: 'src/hooks', }, prerender: { default: true, }, } };

Continue to use tags

In svelte.config.js ... (import aliases can be whatever you want)

1. import svelte_preprocess from 'svelte-preprocess'
2. import autoprefixer from 'autoprefixer'
3. pass the Svelte preprocessor to Kit's preprocess config option and pass the postcss plugin to that Svelte preprocessor:

svelte.config.js

import svelte_proprocess from 'svelte-process'
import autoprefixer from 'autoprefixer'

const config = {
    // Consult https://github.com/sveltejs/svelte-preprocess for more info
    preprocess: [
        svelte_preprocess({
            postcss: {
                plugins: [autoprefixer()]
            }
        })
    ]
}

import adapter from '@sveltejs/adapter-auto'; import preprocess from 'svelte-preprocess'; import { mdsvex } from 'mdsvex'; import remarkMath from 'remark-math'; import rehypeKatex from 'rehype-katex-svelte'; /** @type {import('@sveltejs/kit').Config} */ const config = { extensions: ['.svelte', '.svx', '.md'], // Consult https://github.com/sveltejs/svelte-preprocess // for more information about preprocessors preprocess: [ preprocess(), mdsvex({ extensions: ['.svx', '.md'], smartypants: true, layout: { project: "./src/routes/projects/layout.svelte", post: "./src/routes/blog/layout.svelte", }, remarkPlugins: [remarkMath], rehypePlugins: [rehypeKatex], }), ], kit: { adapter: adapter({ edge: false, external: [], split: false }) } }; export default config;

Have you tried https://github.com/sveltejs/svelte-preprocess

// We have changed the adapter line to use adapter-node@next import adapter from '@sveltejs/adapter-node@next'; import preprocess from 'svelte-preprocess'; /** @type {import('@sveltejs/kit').Config} */ const config = { // Consult https://github.com/sveltejs/svelte-preprocess // for more information about preprocessors preprocess: preprocess(), kit: { // We have changed this to point to a build directory adapter: adapter({ out: 'build' }) } }; export default config;