rollup.config.js

import svelte from 'rollup-plugin-svelte';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import livereload from 'rollup-plugin-livereload';
import { terser } from 'rollup-plugin-terser';
import { generateSW } from 'rollup-plugin-workbox';

const production = !process.env.ROLLUP_WATCH;

function serve() {
  let server;

  function toExit() {
    if (server) server.kill(0);
  }

  return {
    writeBundle() {
      if (server) return;
      server = require('child_process').spawn('npm', ['run', 'start', '--', '--dev'], {
        stdio: ['ignore', 'inherit', 'inherit'],
        shell: true
      });

      process.on('SIGTERM', toExit);
      process.on('exit', toExit);
    }
  };
}

export default {
  input: 'src/main.js',
  output: {
    sourcemap: true,
    format: 'iife',
    name: 'app',
    file: 'public/build/bundle.js'
  },
  plugins: [
    svelte({
      // enable run-time checks when not in production
      dev: !production,
      // we'll extract any component CSS out into a separate file - better for performance
      css: css => {css.write('bundle.css');}
    }),

    resolve({
      browser: true,
      dedupe: ['svelte']
    }),

    // convert CommonJS modules to ES6
    commonjs(),

    // In dev mode, call `npm run start` once the bundle has been generated
    !production && serve(),

    // Watch the `public` directory and refresh the browser on changes when not in production
    !production && livereload('public'),

    // generate service worker and add charges folder to precache
    production && generateSW({
      swDest: './public/sw.js',
      globDirectory: 'public/charges/',
      globPatterns: [
        '**/*.{svg}'
      ],
      cacheId: "armoria",
      cleanupOutdatedCaches: true,
      runtimeCaching: [{
        urlPattern: '*.{js, json, png}',
        handler: 'NetworkFirst',
        options: {
          cacheName: 'armoria-cache',
        }
      }]
    }),

    // minify
    production && terser()
  ],
  watch: {
    clearScreen: false
  }
};