rollup.config.js

import fs from 'fs'
import path from 'path'
import typescript from '@rollup/plugin-typescript'
import replace from '@rollup/plugin-replace'
import terser from '@rollup/plugin-terser'
import babel from '@rollup/plugin-babel'
import pkg from './package.json'

const NODE_ENV = process.env.NODE_ENV
const APP_FILENAME = 'index'
const APP_SRC_DIRNAME = 'src'
const APP_BUILD_DIRNAME = 'dist'
const APP_BUILD_FILENAME = 'object-parser'
const APP_BUILD_UMD_NAME = 'objectParser'

const input = path.join(APP_SRC_DIRNAME, `${APP_FILENAME}.ts`)
const output = path.join(APP_BUILD_DIRNAME, `${APP_BUILD_FILENAME}`)

const splitedVersion = pkg.version.split('.')

if (fs.existsSync(APP_BUILD_DIRNAME)) {
  fs.rmSync(APP_BUILD_DIRNAME, { recursive: true, force: true })
}

const rollupConfig = {
  input,
  output: [
    {
      file: `${output}.js`,
      format: 'umd',
      exports: 'named',
      name: APP_BUILD_UMD_NAME,
    },
  ],
  plugins: [
    typescript(),
    replace({
      preventAssignment: true,
      'process.env.VERSION_MAJOR': splitedVersion[0],
      'process.env.VERSION_MINOR': splitedVersion[1],
      'process.env.VERSION_PATCH': splitedVersion[2],
    }),
  ],
}

if (NODE_ENV === 'production') {
  const removeComments = terser({
    compress: false,
    mangle: false,
    format: {
      beautify: true,
      comments: false,
    },
  })

  rollupConfig.output[0].plugins = [removeComments]
  rollupConfig.output.push(
    ...[
      {
        file: `${output}.esm.js`,
        format: 'esm',
        exports: 'named',
        plugins: [removeComments],
      },
      {
        file: `${output}.min.js`,
        format: 'umd',
        exports: 'named',
        name: APP_BUILD_UMD_NAME,
        plugins: [terser({ compress: { unsafe_arrows: true, passes: 2 } })],
      },
    ]
  )

  rollupConfig.plugins.push(
    babel({
      babelHelpers: 'bundled',
      exclude: 'node_modules/**',
    })
  )
}

export default rollupConfig