rollup.config.js

import svelte from 'rollup-plugin-svelte';
import serve from 'rollup-plugin-serve';
import autoPreprocess from 'svelte-preprocess';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import html from '@gen/rollup-plugin-generate-html';
import pkg from './package.json';

const dev = process.env.NODE_ENV === 'development'

const name = pkg.name
	.replace(/^(@\S+\/)?(svelte-)?(\S+)/, '$3')
	.replace(/^\w/, m => m.toUpperCase())
	.replace(/-\w/g, m => m[1].toUpperCase());

const plugins = [
	svelte({
		preprocess: autoPreprocess()
	}),
	commonjs(),
	resolve()
];

if (dev) {
	plugins.push(
		html({
			template: 'demo/index.html',  // Default undefined
		filename: 'index.html', // Default index.html
		publicPath: 'dist' // Default undefined
		}),
		serve({
			contentBase: 'dist',
			port: 12001
		})
	)
}

export default {
	input: dev ? './demo/demo.js' : 'src/index.js',
	output: [
		{ file: pkg.module, 'format': 'es' },
		{ file: pkg.main, 'format': 'umd', name }
	],
	plugins: plugins
};