rollup.config.mjs

import commonjs from '@rollup/plugin-commonjs'
import json from '@rollup/plugin-json'
import nodeResolve from '@rollup/plugin-node-resolve'
import typescript from '@rollup/plugin-typescript'
import { terser } from 'rollup-plugin-terser'
import packageJson from './package.json' assert { type: 'json' }

const { main, module: moduleFile, dependencies = {} } = packageJson

const plugins = [
  json({ preferConst: true }),
  nodeResolve(),
  commonjs(),
  typescript({ resolveJsonModule: false }),
  !process.env.ROLLUP_WATCH && terser(),
]

export default [
  {
    plugins,
    external: Object.keys(dependencies),
    input: `src/entry.ts`,
    output: { file: main, format: 'cjs', exports: 'named' },
  },
  {
    plugins,
    input: `src/entry.ts`,
    output: { file: moduleFile, format: 'esm' },
  },
  {
    plugins,
    input: `src/polyfill.browser.ts`,
    output: { file: main.replace(/\.[^.]+$/, '.browser.js'), format: 'iife' },
  },
]