rollup.config.js

import babel from '@rollup/plugin-babel'
import commonjs from '@rollup/plugin-commonjs'
import json from '@rollup/plugin-json'
import resolve from '@rollup/plugin-node-resolve'
import replace from '@rollup/plugin-replace'
import externals from 'rollup-plugin-node-externals'
import pkg from './package.json'
import postcss from 'rollup-plugin-postcss'
import { terser } from 'rollup-plugin-terser'

const ENV_PRODUCTION = 'production'
const ENV_DEVELOPMENT = 'development'
const env = process.env.NODE_ENV || ENV_PRODUCTION

if (env !== ENV_DEVELOPMENT && env !== ENV_PRODUCTION) {
  console.error(`
Unsupported NODE_ENV: ${env}
Should be either "${ENV_DEVELOPMENT}" or "${ENV_PRODUCTION}"
`)
  process.exit(1)
}
const extensions = ['.js', '.jsx', '.ts', '.tsx']

export default {
  input: `src/${pkg.name}.ts`,
  output: [
    {
      file: pkg.module,
      format: 'es',
      exports: 'named',
      preserveModulesRoot: 'src'
    }
  ].filter(Boolean),
  watch: {
    include: 'src/**'
  },
  plugins: [
    externals({ peerDeps: true, deps: true }),
    replace({
      'process.env.NODE_ENV': JSON.stringify(env),
      preventAssignment: true
    }),
    json(),
    postcss({
      extensions: ['.css']
    }),
    resolve({
      browser: true,
      extensions
    }),
    commonjs(),
    babel({
      rootMode: 'upward',
      extensions,
      babelHelpers: 'runtime',
      include: ['./src/**/*']
    }),
    terser()
  ]
}