rollup.config.js

import { merge } from 'lodash';
import babel from 'rollup-plugin-babel';
import commonjs from 'rollup-plugin-commonjs';
import resolve from 'rollup-plugin-node-resolve';
import replace from 'rollup-plugin-replace';
import sourceMaps from 'rollup-plugin-sourcemaps';
import uglify from 'rollup-plugin-uglify';

function generateConfig(overrides, minify = false, externalHelpers = false) {
  return merge(
    {},
    {
      input: 'src/index.js',
      output: {
        globals: { react: 'React', 'react-is': 'ReactIs', 'prop-types': 'PropTypes' },
        name: 'Buttermilk',
        sourcemap: true,
      },
      external: ['react', 'react-is', 'prop-types'],
      plugins: [
        resolve(),
        babel({
          babelrc: false,
          runtimeHelpers: externalHelpers,
          presets: [
            [
              '@babel/preset-env',
              {
                modules: false,
              },
            ],
            '@babel/preset-react',
          ],
        }),
        commonjs({
          ignoreGlobal: true,
        }),
        sourceMaps(),
        replace({
          'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV),
        }),
        minify ? uglify() : null,
      ].filter(Boolean),
    },
    overrides
  );
}

export default [
  generateConfig({
    output: {
      file: 'dist/standalone.js',
      format: 'iife',
    },
  }),
  generateConfig(
    {
      output: {
        file: 'dist/standalone.min.js',
        format: 'iife',
      },
    },
    true
  ),
  generateConfig(
    {
      output: {
        file: 'dist/cjs.js',
        format: 'cjs',
      },
    },
    false,
    true
  ),
  generateConfig(
    {
      output: {
        file: 'dist/cjs.min.js',
        format: 'cjs',
      },
    },
    true,
    true
  ),
  generateConfig(
    {
      output: {
        file: 'dist/es.js',
        format: 'es',
      },
    },
    false,
    true
  ),

  generateConfig(
    {
      output: {
        file: 'dist/es.min.js',
        format: 'es',
      },
    },
    true,
    true
  ),
];