rollup.config.js

import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import babel from 'rollup-plugin-babel';
import postcss from 'rollup-plugin-postcss';
import multiInput from 'rollup-plugin-multi-input';
import pkg from './package.json';

export default [

  // Just for CommonJS (for Node) build.
  // Instructions for publishing a beta version:
  // npm version pre<major|minor|patch> --preid=beta (e.g. npm version preminor --preid=beta)
  // npm version 2.0.0-beta.1
  // npm publish --tag=beta --otp=000000

  {
    input: 'src/index.js',
    external: [...Object.keys(pkg.dependencies), ...Object.keys(pkg.peerDependencies)],
    output: { dir: pkg.main, format: 'cjs' },
    plugins: [
      postcss({
        modules: true,
      }),
      babel(),
      resolve(),
      commonjs(),
    ],
  },


  // ES module (for bundlers) build

  {
    input: ['src/**/*.js'],
    external: [...Object.keys(pkg.dependencies), ...Object.keys(pkg.peerDependencies)],
    output: { dir: pkg.module, format: 'es' },
    plugins: [
      postcss({
        modules: true,
      }),
      babel(),
      resolve(),
      commonjs(),
      multiInput(),
    ],
  },
];