Rollup configuration for production

rollup.prod.js

import babel from "rollup-plugin-babel";
import resolve from "rollup-plugin-node-resolve";
import postcss from "rollup-plugin-postcss";
import commonjs from "rollup-plugin-commonjs";
import copy from "rollup-plugin-copy-assets";
import progress from "rollup-plugin-progress";
import visualizer from "rollup-plugin-visualizer";
import filesize from "rollup-plugin-filesize";

let external = [
	"react",
	"@shopify/polaris",
	"prop-types",
	"@shopify/react-utilities",
	"react-perfect-scrollbar",
	"react-dom",
	"validator",
	"react-rte",
	"warning",
	"invariant",
	"@shopify/javascript-utilities/other",
	"babel-runtime/helpers/classCallCheck",
	"babel-runtime/helpers/createClass",
	"@shopify/javascript-utilities/events",
	"@shopify/javascript-utilities/geometry",
	"lodash-decorators/throttle"
];

export default {
	input: "src/polaris.js",
	plugins: [
		babel(
			{
				babelrc: false,
				include: "src/**/*.js",
				exclude: [
					"node_modules/**"
				],
				presets: [["env", {modules: false}], "react", "es2015-rollup"],
				plugins: ["transform-object-rest-spread", "transform-class-properties", "external-helpers", "transform-runtime"],
				runtimeHelpers: true,
				externalHelpers: false
			}
		),
		resolve({
			jsnext: true,
			main: true,
			browser: true,
		}),
		postcss({
			modules: false,
			extract: "dist/polaris.css",
			inject: false,
			extensions: [".css"],
			sourceMap: "inline"
		}),
		commonjs(),
		copy({
			assets: [
				"./src/polaris.scss",
				"./src/styles/"
			]
		}),
		progress(),
		visualizer(),
		filesize(),
	],
	external: external,
	output: [
		{
			file: "dist/polaris.js",
			format: "cjs",
			moduleName: "polaris",
			sourceMap: true
		},
		{
			file: "dist/polaris.es.js",
			format: "es",
			moduleName: "polaris",
			sourceMap: true
		}
	]
};