require vs ES6 import

[yarax]

Are there any plans to move from CommonJs modules to ES6 modules and import syntax?

[bnoordhuis]

You can find some discussion about require() vs. import here and there's more discussion scattered across various repositories.

In a nutshell, require() is not going anywhere - removing it would break too much for too little gain - but we'll almost certainly end up supporting ES6 import/export somehow, details TBD.

Support for ES6 modules first needs to land in V8. The tracking bug is here but it's blocked by finalization of the module loader spec.

[yarax]

@bnoordhuis thanks!

[romu70]

Hi,
Newbie question, if I write a ES6 class, like this one:

'use strict';

class User {
  constructor(username, email) {
    this.email = email;
    this.username = username;
  }
}

What's the correct syntax to export this class as a module? Tried many things export class..., module.exports = class..., export User as User, nothing seems to work, so I guess I make a mistake somewhere.

Thanks.

[bnoordhuis]

@romu70 import/export isn't supported yet but module.exports = ... should work:

// a.js
class A {
  // ...
}
module.exports = A;

Or:

// b.js
module.exports = class B {
  // ...
};

[StyMaar]

Support for ES6 modules first needs to land in V8.

Why ?

The current module syntax doesn't rely on any V8 support to work and import/export can be transpilled to this model. Node's concerns about module loading and browsers' ones are quite different.
I don't really understand how the whatwg module loader spec should affect Node, as long as the import/export semantic is already specified.

[bnoordhuis]

Is your question "why won't node.js support import/export until V8 does"? Because node.js doesn't parse JS code, V8 does, and we're not a transpiler.

[StyMaar]

Fair enough, thanks.

[paulwalker]

Does v5+ of V8 (and consequently nodejs v6+) support es6 modules yet?

[bnoordhuis]

@paulwalker No, not yet. Maybe in node.js v7.

[styfle]

You can star v8 Bug 1569.

[franciscop]

@lordKnighton why was this issue closed? I'd love to see this implemented as well

[getkey]

@franciscop

Support for ES6 modules first needs to land in V8. The tracking bug is here but it's blocked by finalization of the module loader spec.

You can star v8 Bug 1569.

[SamMorrowDrums]

Just came back here for an update. Currently there is blocking bug. https://bugs.chromium.org/p/v8/issues/detail?id=5685

Really looking forward to this finally dropping, it is so close, and the last thing that's preventing me dropping babel on some projects.

[xgqfrms-GitHub]

https://github.com/nodejs/node/wiki/ES6-Module-Detection-in-Node
http://stackoverflow.com/questions/37132031/nodejs-plans-to-support-import-export-es6-es2015-modules
http://stackoverflow.com/questions/31354559/using-node-js-require-vs-es6-import-export

https://nodejs.org/en/docs/es6/

[mayeaux]

I've been reading up on ES Modules being supported in native node, it looks like there's two simultaneous discussions of how to implement it (ie, whether to use the .mjs file extension) and then also a consideration around a bug in V8.

Which is the true current blocker? Does anyone have an ETA on when the blocker should be smoothed out and V8 will support the ES Module syntax? I'm in the same boat as a few others here who are hoping to drop babel, thanks!

[mweels]

Why would they support it when you could use transcompilers?

[dandv]

Since 2017-Jan-10, V8 supports modules.

[mayeaux]

Awesome! And it looks like nightly node (and 7.4) uses v8 version: 5.4.500.46

Whereas the latest V8 version with es modules landed is around: 5.7.458

Wonder how long it will take to land in node 🤔 I don't actively develop node do any devs have a guesstimate?

[MylesBorins]

@mrmayfield it should eventually be on this experimental branch

fwiw it landing in V8 will be only the first step towards proper support in node. I believe we are currently tracking V8 5.5 for inclusion in node 8... but other people will know better.

/cc @nodejs/v8

[mayeaux]

Thanks @MylesBorins
So there's still determinations to be made in regards to how to implement the actual feature even though it's now landed in V8? Sorry I'm a bit unfamiliar with the intricacies of how Node/V8 interact.

[targos]

@mrmayfield yes. It is happening here: nodejs/node-eps#39

[dandv]

From James M Snell's Update on ES6 Modules in Node.js:

Work is in progress but it is going to take some time — We’re currently looking at around a year at least.

[mk-pmb]

How's progress so far?

[srameshr]

On node 8.x, its not supported yet.

[caonUlisses]

You can use it with for .mjs files with the --experimental-modules flag, as had being pointed already, it's experimental, but it's already happening.

[cztomsik]

Currently, it's not possible to import the same file from chrome and node.js at the same time. Something should be done about this.

[devsnek]

@cztomsik

Currently, it's not possible to import the same file from chrome and node.js at the same time. Something should be done about this.

i'm not sure what exactly is lacking? obviously browsers won't implement node's loader algorithm or builtin modules. there is discussion around allowing node to import from urls but there's a lot of work to do behind that.

[cztomsik]

the problem is *.mjs file extension (which is not application/javascript and so the chrome will reject it) 2018-03-14 0:42 GMT+01:00 Gus Caplan <notifications@github.com>:

…

Currently, it's not possible to import the same file from chrome and node.js at the same time. Something should be done about this. i'm not sure what exactly is lacking? obviously browsers won't implement node's loader algorithm or builtin modules. there is discussion around allowing node to import from urls but there's a lot of work to do behind that. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#53 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ADXRCub3-r_WjTdDNRH-Q_vjuQf2z5vRks5teFmAgaJpZM4G4Bmk> .

[StyMaar]

application/javascript is a MIME type set by the web-server in the HTTP response header.
Most http server automatically set the application/javascript MIME header when delivering files with a .js extension but you can configure your web server to do the same for .mjs.

[cztomsik]

there are cases when you can't 2018-03-14 12:38 GMT+01:00 StyMaar <notifications@github.com>:

…

application/javascript is a MIME type set by the web-server in the HTTP response header. Most http server automatically set the application/javascript MIME header when delivering files with a .js extension but you can configure your web server to do the same for .mjs. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#53 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ADXRCtTwe8RB4at-bW6RfwUgnE_a768Kks5teQFNgaJpZM4G4Bmk> .

[StyMaar]

What's your use-case ?

In general, if you can't configure the MIME type, and the .mjs extension is misbehaving on the server, then the bug is on the webserver's / hosting service side and should be filed there.

I'm still curious about your specific case though.

[devsnek]

for those of you following along at home: https://datatracker.ietf.org/submit/status/88872/

[styfle]

Currently, it's not possible to import the same file from chrome and node.js at the same time. Something should be done about this.

@cztomsik There is something being done about it on the web side of things too.
See https://github.com/domenic/package-name-maps