rollup.config.js

const { rollup } = require('rollup');
const babel = require('rollup-plugin-babel');
const resolve = require('@rollup/plugin-node-resolve');
const commonJS = require('@rollup/plugin-commonjs');
const { uglify } = require('rollup-plugin-uglify');
const sizes = require('rollup-plugin-sizes');
const filesize = require('rollup-plugin-filesize');

const production = process.env.NODE_ENV === 'production';

module.exports = module => {
  return rollup({
    input: module.input,
    plugins: [
      babel({
        exclude: /node_modules\/(?!(dom7|ssr-window|swiper|micromodal|lozad)\/).*/,
        presets: [
          [
            '@babel/preset-env',
            {
              modules: false
            }
          ]
        ],
        plugins: [
          ['@babel/transform-react-jsx', { pragma: 'h' }],
          '@babel/plugin-proposal-class-properties'
        ]
      }),
      resolve(),
      commonJS({
        // ignore importing optional momentjs, which comes with pikaday
        ignore: ['moment']
      }),
      production && uglify(),
      production && sizes(),
      production && filesize()
    ]
  })
    .then(bundle => {
      return bundle.write({
        file: module.file,
        format: 'iife',
        sourcemap: !production
      });
    })
    .catch(err => {
      console.error(err);
      throw err;
    });
};