rollup with react-reason starter repo

rollup.config.js

var rollup = require('rollup').rollup;
var commonjs = require('rollup-plugin-commonjs');
var nodeResolve = require('rollup-plugin-node-resolve');
var replace = require('rollup-plugin-replace');

const entry = 'simple/simpleRoot';
const results = [];
const dest = 'bundle.js';
const ENV = 'development';
// const ENV = 'production';

rollup({
  entry: 'lib/es6/src/' + entry + '.js',
  dest: dest,
  format: 'iife',
  plugins: [
    replace({
      'process.env.NODE_ENV': JSON.stringify(ENV),
    }),
    nodeResolve({
      jsnext: true,
      main: true,
      module: true,
    }),

    commonjs({
      // non-CommonJS modules will be ignored, but you can also
      // specifically include/exclude files
      include: 'node_modules/**',  // Default: undefined
      // exclude: [ 'node_modules/foo/**', 'node_modules/bar/**' ],  // Default: undefined

      // if true then uses of `global` won't be dealt with by this plugin
      ignoreGlobal: false,  // Default: false

      // if false then skip sourceMap generation for CommonJS modules
      sourceMap: false,  // Default: true

      // explicitly specify unresolvable named exports
      // (see below for more details)
      namedExports: {
        'react': [
          'createClass',
          'createElement',
        ],
        'react-dom': [
          'render'
        ]
      },  // Default: undefined

      // sometimes you have to leave require statements
      // unconverted. Pass an array containing the IDs
      // or a `id => boolean` function. Only use this
      // option if you know what you're doing!
      // ignore: [ 'conditional-runtime-dependency' ]
    }),
  ]
})
.then((all) => {
  return all.write({
    dest: dest,
    format: 'iife'
  });
})
.catch(console.log);