rollup.config.mjs

import svelte from 'rollup-plugin-svelte';
import commonjs from '@rollup/plugin-commonjs';
import resolve from '@rollup/plugin-node-resolve';
import { terser } from 'rollup-plugin-terser';
import { sveltePreprocess } from 'svelte-preprocess';
import typescript from '@rollup/plugin-typescript';
import postcss from 'rollup-plugin-postcss';
import tailwindcss from 'tailwindcss';
import tailwindConfig from './tailwind.config.js';

const production = !process.env.ROLLUP_WATCH;

export default {
	input: 'src/main.ts',
	output: {
		sourcemap: true,
		format: 'iife',
		name: 'app',
		file: 'out/compiled/bundle.js'
	},
	plugins: [
		svelte({
			preprocess: sveltePreprocess({ sourceMap: !production }),
			compilerOptions: {
				// enable run-time checks when not in production
				dev: !production
			}
		}),
		// we'll extract any component CSS out into
		// a separate file - better for performance
		postcss({
			config: {
			  path: './postcss.config.js',
			},
			extensions: [".css"],
			minimize: true,
			extract: true,
			plugins: [tailwindcss(tailwindConfig)],
			output: "bundle.css"
		}),

		// If you have external dependencies installed from
		// npm, you'll most likely need these plugins. In
		// some cases you'll need additional configuration -
		// consult the documentation for details:
		// https://github.com/rollup/plugins/tree/master/packages/commonjs
		resolve({
			browser: true,
			dedupe: ['svelte']
		}),
		commonjs(),
		typescript({
			sourceMap: !production,
			inlineSources: !production
		}),

		// If we're building for production (npm run build
		// instead of npm run dev), minify
		production && terser()
	],
	watch: {
		clearScreen: false
	}
};