rollup.config.js

import resolve from 'rollup-plugin-node-resolve';
import sourceMaps from 'rollup-plugin-sourcemaps';

export default {
  entry: `compiled/formik.js`,
  targets: [{ dest: 'dist/formik.es6.js', format: 'es' }, { dest: 'dist/formik.js', format: 'cjs' }],
  sourceMap: true,
  // Indicate here external modules you don't wanna include in your bundle (i.e.: 'lodash')
  external: ['react'],
  globals: {
    react: 'React',
  },
  exports: 'named',
  plugins: [
    // Allow node_modules resolution, so you can use 'external' to control
    // which external modules to include in the bundle
    // https://github.com/rollup/rollup-plugin-node-resolve#usage
    resolve(),
    // Resolve source maps to the original source
    sourceMaps(),
  ],
};