rollup.config.mjs

import commonjs from '@rollup/plugin-commonjs'
import dts from 'rollup-plugin-dts'
import { nodeResolve } from '@rollup/plugin-node-resolve'
import replace from '@rollup/plugin-replace'
import summary from 'rollup-plugin-summary'
import { swc, minify } from 'rollup-plugin-swc3'

import template from 'rollup-plugin-html-literals'

import pkg from './package.json' assert { type: 'json' }

const input = './src/index.ts',
  dev = './dev/index.js',
  extensions = ['.js', '.ts'],
  external = [
    'lit',
    'lit/decorators.js',
    'lottie-web',
    'fflate'
  ],
  plugins = ( dev = false, preferBuiltins = true ) => {
    return [
      template(),
      replace({
        preventAssignment: false,
        'Reflect.decorate': 'undefined'
      }),
      nodeResolve({
        extensions,
        jsnext: true,
        module: true,
        browser: true,
        preferBuiltins
      }),
      commonjs(),
      swc(),
      !dev && minify(),
      !dev && summary(),
    ]
  }

export default [
  {
    input: './types/index.d.ts',
    output: {
      file: pkg.types,
      format: 'esm'
    },
    plugins: [
      dts(),
    ]
  },
  {
    input,
    output: {
      extend: true,
      file: pkg.main,
      format: 'iife',
      name: pkg.name,
    },
    onwarn(warning, warn) {
      if (warning.code === 'THIS_IS_UNDEFINED') return
      warn(warning)
    },
    plugins: plugins(false, false),
  },
  {
    input,
    output: {
      extend: true,
      file: dev,
      format: 'iife',
      name: pkg.name,
    },
    onwarn(warning, warn) {
      if (warning.code === 'THIS_IS_UNDEFINED') return
      warn(warning)
    },
    plugins: plugins(true, false),
  },
  {
    input,
    external,
    output: [
      {
        file: pkg.module,
        format: 'esm',
      },
      {
        file: pkg.exports['.'].require,
        format: 'cjs'
      }
    ],
    onwarn(warning, warn) {
      if (warning.code === 'THIS_IS_UNDEFINED') return
      warn(warning)
    },
    plugins: plugins(),
  }
]