rollup.config.js

import commonjs from "@rollup/plugin-commonjs";
import resolve from "@rollup/plugin-node-resolve";
import css from "rollup-plugin-css-only";
import injectProcessEnv from "rollup-plugin-inject-process-env";
import livereload from "rollup-plugin-livereload";
import svelte from "rollup-plugin-svelte";
import { terser } from "rollup-plugin-terser";

const production = !process.env.ROLLUP_WATCH;
const EMULATE = !!process.env.EMULATE;

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({
			compilerOptions: {
				// 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({ output: "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/plugins/tree/master/packages/commonjs
		resolve({
			browser: true,
			dedupe: ["svelte"],
		}),
		commonjs(),
		injectProcessEnv({
			API_KEY: process.env.API_KEY,
			AUTH_DOMAIN: process.env.AUTH_DOMAIN,
			DATABASE_URL: process.env.DATABASE_URL,
			PROJECT_ID: process.env.PROJECT_ID,
			STORAGE_BUCKET: process.env.STORAGE_BUCKET,
			MESSAGING_SENDER_ID: process.env.MESSAGING_SENDER_ID,
			APP_ID: process.env.APP_ID,
			EMULATE: process.env.EMULATE,
			APP_ENV: process.env.APP_ENV,
		}),

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

		// 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(),
	],
	watch: {
		clearScreen: false,
	},
};