rollup.config.ts

import { RollupOptions } from 'rollup';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import typescript from '@rollup/plugin-typescript';
import litCss from 'rollup-plugin-lit-css';
import terser from '@rollup/plugin-terser';
import serve from 'rollup-plugin-serve';
import livereload from 'rollup-plugin-livereload';

const isProduction = process.env.NODE_ENV === 'production';

const config: RollupOptions = {
  input: 'src/index.ts',
  output: {
    file: 'dist/main.js',
    format: 'esm',
    sourcemap: true,
  },
  plugins: [
    resolve(),
    commonjs(),
    typescript({ tsconfig: './tsconfig.json' }),
    litCss(),
    isProduction && terser(),
    !isProduction && serve({
      contentBase: 'dist',
      port: 8080,
    }),
    !isProduction && livereload('dist'),
  ],
};

export default config;