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 replace from "@rollup/plugin-replace";
import { injectManifest } from "rollup-plugin-workbox";

const production = !process.env.ROLLUP_WATCH;

export default {
  input: "src/main.js",
  output: {
    sourcemap: true,
    format: "iife",
    name: "app",
    file: "public/bundle.js",
  },
  plugins: [
    replace({ "sw.path": production ? "/public/sw.js" : "/sw.js" }),

    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("public/bundle.css");
      },
    }),

    // If you have external dependencies installed from
    // npm, you'll most likely need these plugins. In
    // some cases you'll need additional configuration —
    // consult the documentation for details:
    // https://github.com/rollup/rollup-plugin-commonjs
    resolve({ browser: true }),
    commonjs(),

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

    // If we're building for production (npm run build
    // instead of npm run dev), minify
    production && terser(),

    injectManifest({
      swSrc: "build/sw.js",
      swDest: "public/sw.js",
      globDirectory: "public/",
      globIgnores: ["index.html"],
      mode: production ? "production" : "development",
    }),
  ],
  watch: {
    clearScreen: false,
  },
};