(node:9511) ExperimentalWarning: The ESM module loader is experimental [closed]

Question

I am trying to use ES6 on server side. I a have separated endpoint from server file:

archive.js:

import { Router } from "express";
const router = Router();

router.get("/", async (req, res) => { "some code"});

export default router;

when i want to import it to my server file like this:

import archive from "./endpoints/archive.js";
app.use("/archive", archive);

it gives me an error:

(node:9565) ExperimentalWarning: The ESM module loader is experimental. internal/modules/run_main.js:54 internalBinding('errors').triggerUncaughtException()

any idea guys? i dont want to go back to require/module.exports

Alliber

What version of nodejs? By default a .js file is assumed to be a CommonJS file, NOT an ESM module unless you have appropriately tagged it in a package.json file. It is much easier to get ESM modules to work by making them .mjs files, not .js files because the loader assumes any .mjs file is an ESM module. Which file does this warning/error occur in? – Srinagar

This was a new directory which i have pulled from github repo. I have tried many things/solutions but it turned out i have to clone to a new directory/environment. Couldnt find the problem or a proper fix but in the new directory/environment i dont have that problem. – Alliber

Answer 1

you can use Node v14.12.0; where this probleme is solved, and read this doc https://nodejs.org/api/esm.html#esm_package_json_type_field

Skied

Answer 2

I realize after a few tries that "--experimental-modules" flag on the "nodemon" causes issues to realize the imports in the whole app so I did update that flag to use the new flag for explicit filenames"--es-module-specifier-resolution=node" and now works perfect here is an article about this new flag : https://nodejs.medium.com/announcing-a-new-experimental-modules-1be8d2d6c2ff

So for explane you can do a script like this:

nodemon --es-module-specifier-resolution=node

Also keep in mind the nodejs version you use a version under 12.XX, 14.XX or the last stable version.

Upgrade Node.js to the latest version on Mac OS

I hoper this helps more developers :)

Muster

I needed to update Node 👍️ – Idiopathy