rollup.config.js

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 css from 'rollup-plugin-css-only';
import pkg from "./package.json";

const production = !process.env.ROLLUP_WATCH;

const { name } = pkg;

const license = `
Copyright (c) 2021 Michael Lucht

Copyright (c) 2016-21 [these people](https://github.com/sveltejs/svelte/graphs/contributors)

    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
    
    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
    
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


`
const addLicense = ()=>({
	name: "add-licenses",
	generateBundle:(options, bundle, isWrite)=>{
		Object.keys(bundle).forEach(v=>{
			bundle[v].code = "/*\n" + license + "\n*/" + bundle[v].code;
		})	
	}
})
export default {
	input: 'src/ripple.js',
	output: [
		{
		  file: pkg.module,
		  format: "es",
		  sourcemap: false,
		  name
		},
		{
		  file: pkg.main,
		  format: "umd",
		  sourcemap: false,
		  name
		}
	  ],
	plugins: [
		svelte({
			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
		css({ 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(),

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