rollup.config.js

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

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

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

const plugins = [
	resolve(),
	commonjs(),
	css(),
	svelte()
]

const output = [
	{ file: `${pkg.module}`, 'format': 'es' },
	{ file: `${pkg.main}`, 'format': 'umd', name }
]

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,
	plugins
}