Remove (node:86710) ExperimentalWarning: The ESM module loader is experimental.

[haraldrudell]

Could we remove the ESM warning, please?

--no-warnings affects Node.js behavior, so that can't be used
For people who write shell executables there's a bloody extra line being output requiring trickery
ESM is so unexperimental since 190423

$ node --experimental-modules src/fsPromisesUtimes.js
(node:86710) ExperimentalWarning: The ESM module loader is experimental.

[devsnek]

esm is still experimental though. the warning will be removed when it isnt.

[guybedford]

Currently the PR to unflag at #29866 which we are hoping to land soon would still output this warning whenever loading an ES module or using a custom loader.

Ideally we would have a nicer way to filter these warnings, but unfortunately it seems these will be around for a little while still.

Stability could be early next year, with the warning removal then. Getting the warning message removed sooner could be something worth considering though if enough people want it.

[devsnek]

closing as answered

[Alhadis]

Currently the PR to unflag at #29866 which we are hoping to land soon would still output this warning whenever loading an ES module or using a custom loader.

@guybedford Just curious, what's the reason for that? I imagined that once --experimental-modules was unflagged, the warning would disappear because ESM imports would be deemed a stable feature.

[sheerun]

flag is not there but it's still experimental, which means you should not use it in production yet

[sheerun]

(or publish any node module that uses es6 modules that is meant to be used with node)

[ghost]

Question: Is the esm module loader a new feature in nodejs?

[rulatir]

Any progress on this?

[valyrie97]

the options is no longer --experimental-loader, its just --loader, but produces the same warning. surely this is an oversight, in some capacity? either it is still experimental, and should not have changed its name, (or maybes its just aliased, if so, it shouldnt be, as to not give false hope, that its no longer experimental), or it isnt experimental, in which case, this warning should not be present.

[andrewshawcare]

Can we at least change the warning to:

Warning: Custom ESM Loaders is a feature and might change at any time

and then add a flag:

NODE_OPTIONS=--suppress-warnings-about-features-that-might-change

[rulatir]

Is this still an issue? If so, why is the issue closed?

[drernie]

I'm seeing an even more confusing version of this:

(node:28745) ExperimentalWarning: `--experimental-loader` may be removed in the future; instead use `register()`:
--import 'data:text/javascript,import { register } from "node:module"; import { pathToFileURL } from "node:url"; register("ts-node/esm", pathToFileURL("./"));'
    at createModuleLoader (node:internal/modules/esm/loader:534:17)
    at loadESM (node:internal/process/esm_loader:21:19)
    at runMainESM (node:internal/modules/run_main:53:21)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:5)
    at node:internal/main/run_main_module:23:47

when I call 'loader=ts-node/esm' with mocha:

  "node-option": [
      "experimental-specifier-resolution=node",
      "loader=ts-node/esm"
  ],

[aggarwalmegha]

Same any fix?

[andrewshawcare]

This error is getting kind of wild.

If the use case is the CLI, why is the suggested fix to drop into a script (or some kind of dynamic eval at the CLI)?

At the context of some (if not all) warnings, there is no register() function option because there is no code being written.

Why not suggest --loader or --register CLI options? Why should people using loaders have to write wrapper scripts?