rollup.config.cjs

const commonjs = require('@rollup/plugin-commonjs');
const resolve = require('@rollup/plugin-node-resolve');
const babel = require('@rollup/plugin-babel');
const pkg = require('./package.json');

const extensions = ['.js', '.jsx', '.ts', '.tsx'];

const name = 'index';

module.exports = {
  input: './src/index.ts',

  // Specify here external modules which you don't want to include in your bundle (for instance: 'lodash', 'moment' etc.)
  // https://rollupjs.org/guide/en/#external
  external: [],

  plugins: [
    // Allows node_modules resolution
    resolve({ extensions }),

    // Allow bundling cjs modules. Rollup doesn't understand cjs
    commonjs(),

    // Compile TypeScript/JavaScript files
    babel({
      extensions,
      babelHelpers: 'bundled',
      include: ['src/**/*'],
    }),
  ],
  output: [
    {
      file: pkg.main,
      format: 'cjs',
    },
    {
      file: pkg.module,
      format: 'es',
    },
    {
      file: pkg.browser,
      format: 'iife',
      name,
      // https://rollupjs.org/guide/en/#outputglobals
      globals: {},
    },
  ],
};