rollup.config.js

//import typescript from 'typescript';
import typescript from 'rollup-plugin-typescript2';
import nodeResolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import replace from 'rollup-plugin-replace';
import serve from 'rollup-plugin-serve';
import livereload from 'rollup-plugin-livereload';
import postcss from 'rollup-plugin-postcss';
import autoprefixer from 'autoprefixer';
//import css from 'rollup-plugin-css-only';
import copy from 'rollup-plugin-copy';
import babili from 'rollup-plugin-babili';

const dev = 'development';
const prod = 'production';

const nodeEnv = parseNodeEnv(process.env.NODE_ENV);

const plugins = [
  replace({
      // The react sources include a reference to process.env.NODE_ENV so we need to replace it here with the actual value
      'process.env.NODE_ENV': JSON.stringify(nodeEnv),
  }),
  // nodeResolve makes rollup look for dependencies in the node_modules directory
  nodeResolve(),
  commonjs({
    // All of our own sources will be ES6 modules, so only node_modules need to be resolved with cjs
    include: 'node_modules/**',
    namedExports: {
      // The commonjs plugin can't figure out the exports of some modules, so if rollup gives warnings like:
      // ⚠️   'render' is not exported by 'node_modules/react-dom/index.js'
      // Just add the mentioned file / export here
      'node_modules/react-dom/index.js': [
        'render'
      ],
      'node_modules/react/index.js': [
        'Component',
        'PropTypes',
        'createElement',
      ]
    }
  }),
  postcss({
    extract: true,  // extracts to `${basename(dest)}.css`
    plugins: [autoprefixer],
    writeDefinitions: true,
    // postcssModulesOptions: { ... }
  }),
  typescript({ }),
  /*
  typescriptPlugin({
      // The current rollup-plugin-typescript includes an old version of typescript, so we import and pass our own version
      typescript,
      // rollup-plugin-typescript will inject some typescript helpers to your files (normally tsc will
      // do this). They however have some ES6 keywords like const so they break older browsers.
      // This instructs rollup-plugin-typescript to import tslib instead, which includes the same helpers
      // in proper format.
      importHelpers: true,
  }),*/
  copy({
    "src/Workers/Worker.js": "assets//Worker.js",
    "src/Workers/libflac3-1.3.2.min.js": "assets//libflac3-1.3.2.min.js",
    "src/Workers/libflac3-1.3.2.min.js.mem": "assets//libflac3-1.3.2.min.js.mem",
    verbose: true
  })
];


if (nodeEnv === dev) {
    // For playing around with just frontend code the serve plugin is pretty nice.
    // We removed it when we started doing actual backend work.
    plugins.push(serve({
        port: 3000,
        verbose: true,
        contentBase: '.'
    }));
    //plugins.push(serve('.'));
    plugins.push(livereload({ watch: 'assets/' }));
}

if (nodeEnv === prod) {
  plugins.push(babili({ comments: false }));
}

export default {
    plugins,
    input: './src/index.tsx',
    output: {
      sourcemap: nodeEnv === dev ? true : false,
      file: './assets//bundle.js',
      format: 'iife'
    }
};

function parseNodeEnv(nodeEnv) {
    if (nodeEnv === prod || nodeEnv === dev) {
        return nodeEnv;
    }
    return dev;
}