rollup.config.js

import babel from 'rollup-plugin-babel';
import replace from 'rollup-plugin-replace';
import commonjs from 'rollup-plugin-commonjs';
import uglify from 'rollup-plugin-uglify';

export default {
  input: 'src/index.js',
  plugins: [
    replace({
      'process.env.NODE_ENV': JSON.stringify('production'),
    }),
    commonjs({
      include: [
        'node_modules/**',
      ],
    }),
    babel({
      exclude: 'node_modules/**', // only transpile our source code
    }),
    uglify({
      compress: {
        warnings: false,
        conditionals: true,
        unused: true,
        comparisons: true,
        sequences: true,
        dead_code: true,
        evaluate: true,
        if_return: true,
        join_vars: true,
      },
      output: {
        comments: false,
      },
    }),
  ],
  output: {
    file: 'lib/index.js',
    format: 'cjs',
  },
  sourcemap: true,
};