rollup.config.js

import resolve from 'rollup-plugin-node-resolve'
import babel from 'rollup-plugin-babel'
// Convert CJS modules to ES6, so they can be included in a bundle
import commonjs from 'rollup-plugin-commonjs'
import postcss from 'rollup-plugin-postcss'
import postcssModules from 'postcss-modules'
import uglify from 'rollup-plugin-uglify'
import url from 'rollup-plugin-url'

const cssExportMap = {}
const isProd = process.env.NODE_ENV === 'production'

export default {
  input: 'src/app.js',
  output: {
    file: 'dist/bundle.js',
    format: 'cjs',
    sourcemap: true
  },
  external: [
    'react',
    'react-proptypes',
    'url',
    'events',
    'classnames',
    'query-string'
  ],
  plugins: [
    resolve({
      preferBuiltins: true
    }),
    url({
      include: ['images/*'], // defaults to .svg, .png, .jpg and .gif files
      emitFiles: true // defaults to true
    }),
    postcss({
      plugins: [
        postcssModules({
          getJSON (id, exportTokens) {
            cssExportMap[id] = exportTokens
          }
        })
      ],
      extensions: ['.css'],
      getExportNamed: false,
      getExport (id) {
        return cssExportMap[id]
      },
      extract: 'dist/bundle.css'
    }),
    babel({
      exclude: 'node_modules/**',
      plugins: ['external-helpers']
    }),
    commonjs({
      namedExports: {
        // left-hand side can be an absolute path, a path
        // relative to the current directory, or the name
        // of a module in node_modules
        'node_modules/react-dom/index.js': ['createPortal', 'findDOMNode'],
        'node_modules/validate.js/validate.js': ['validate'],
        'node_modules/react-is/index.js': ['isValidElementType']
      }
    }),
    isProd && uglify(),
  ]
}