[lscharen]

> Notice I have changed the extension from .js to .mjs. Don’t worry, either extension can be used. And you are going to run into issues with either choice

As someone that has used module systems from dojo to CommonsJS to AMD to ESM with webpack and esbuild and rollup and a few others thrown in ... this statement hits hard.

[SCLeo]

Yeah, the commonjs to esm transition has been the python 2 to python 3 transition of JavaScript, except the benefits are limited (at least compared to the hassle created).

There are many libraries that have switched to esm only (meaning they don't support commonjs), but even today, the best way to find the last commonjs version of those libraries is to go to the "versions" tab on npm, and find the most downloaded version in the last month, and chances are, that will be the last commonjs version.

Yes, in a vacuum, esm is objectively a better than commonjs, but how tc39 almost intentionally made it incompatible with commonjs (via top-level awaits) is just bizarre to me.

[eyelidlessness]

It had to be incompatible with CommonJS regardless of top level await. There is no imaginable scenario where browsers would ship a module system with synchronous request and resolution semantics. A module graph can be arbitrarily deep, meaning that synchronous modules would block page load for arbitrarily deep network waterfalls. That’s a complete non-starter.

Given that, top-level await is a sensible affordance, which you’d have to go out of your way to block because async modules already have the same semantics.

Recently, Node has compromised by allowing ESM to be loaded synchronously absent TLA, but that’s only feasible because Node is loading those models from the file system, rather than any network-accessible location (and because it already has those semantics for CJS). That compromise makes sense locally, too. But it still doesn’t make sense in a browser.

[apatheticonion]

Bundler engineer here. ESM is great when it comes to build-time optimisations. When a bundler runs into CJS code it literally deopts the output to accommodate - so from that side it's amazing.

But also, there's a special place in hell for the people that decided to add default exports, "export * from" and top level await.

Commonjs is also very weird as a "module" instance can be reassigned to a reference of another module

module.exports = require('./foo')

and there's no way to do this in ESM (for good reason, but also no one warned us). In fact major projects like React use CJS exports and the entire project cannot be optimized by bundlers. So, rather than porting to ESM, they created a compiler LOL

[bubblyworld]

Yeah, modules in jsland are just trauma... now we have import maps in the browser too. Let's see what kinds of fun we can have with those.

[ajayvk]

A recent improvement in import map support in the browser https://shopify.engineering/resilient-import-maps

[goodthink]

I recently found out that the Function object will compile any javascript you care to feed to it. At runtime! new Function('class MyClass { ...}; return MyClass') My system does not allow for "imports". No npm etc. So this is a bit of a lifesaver for me. I realize in js land it may not be as useful but it is pretty handy.

[zackify]

That’s why everyone should be using bun.sh

[VWWHFSfQ]

Web dev is full of "you should just use some other tool that I like"

I'm convinced that 90% of the JavaScript ecosystem only exists to build tools for itself. It's tools all the way down

[BostonFern]

Won’t .esm.js work?