rollup.config-ssr.js

import svelte from 'rollup-plugin-svelte';
import sveltePreprocess from 'svelte-preprocess';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import svg from 'rollup-plugin-svg';
import json from '@rollup/plugin-json';
import dsv from '@rollup/plugin-dsv';
import execute from 'rollup-plugin-execute';

const preprocess = sveltePreprocess({
	postcss : {
		plugins : [ require('autoprefixer') ]
	}
});

export default {
	input   : 'src/components/App.svelte',
	output  : {
		format  : 'cjs',
		file    : '.tmp/ssr.js',
		exports : 'auto'
	},
	plugins : [
		svelte({
			compilerOptions : { generate: 'ssr' },
			emitCss         : false,
			preprocess
		}),
		resolve({
			browser : true,
			dedupe  : [ 'svelte' ]
		}),
		commonjs(),
		json(),
		dsv(),
		svg(),
		execute('node scripts/pre-render.js')
	]
};