sharing code between bundles, explicitly

.gitignore

/node_modules
/package-lock.json

/dist

README.md

sharing code between bundles, explicitly

here the core bundle includes and exposes utilities, which are imported and invoked by an auxiliary bundle

Getting Started

• ensure Node is installed

• npm install downloads dependencies

• npm start builds and executes bundles

build.js

#!/usr/bin/env node
import * as esbuild from "esbuild";
import { fileURLToPath } from "node:url";
import path from "node:path";

let ROOT_DIR = path.dirname(fileURLToPath(import.meta.url));
await build({
    entryPoints: [
        path.resolve(ROOT_DIR, "./index.core.js"),
        path.resolve(ROOT_DIR, "./index.aux.js")
    ],
    bundle: true,
    format: "esm",
    target: "es2022",
    external: ["./index.*.js"],
    outdir: path.resolve(ROOT_DIR, "./dist")
});

async function build(config) {
    let { watch, serve, ...settings } = config;
    if (watch || serve) {
        let context = await esbuild.context(settings);
        await Promise.all[
            serve && context.serve(),
            watch && context.watch()
        ];
    } else {
        await esbuild.build(settings);
    }
}

geo.js

export function distance(dx, dy) {
	return Math.sqrt(dx ** 2 + dy ** 2);
}

index.aux.js

import { distance } from "./geo.js";
import { log, STATE } from "./index.core.js";

log("AUX", STATE, "hello world");
log("AUX", "Δ", distance(5, 7));

index.core.js

import { log } from "./util.js";

export { log };

export let [STATE] = crypto.randomUUID().split("-");

log("CORE", STATE, "hello world");

setTimeout(async () => {
	log("CORE", STATE, "loading aux");
	await import("./index.aux.js");
}, 1000);

overview.drawio.png

package.json

{
	"scripts": {
		"start": "./build.js && node ./dist/index.core.js"
	},
	"type": "module",
	"devDependencies": {
		"esbuild": "^0.19.7"
	}
}

util.js

export function log(prefix, ...msg) {
	console.log(`[${prefix}]`.padEnd(6, " "), ...msg);
}