I want use ES6 import in browser side js

[gtk2k]

Note: for support questions, please use one of these channels: stackoverflow or slack

You want to:

• report a bug
• request a feature

Current behaviour

Steps to reproduce (if the current behaviour is a bug)

Note: the best way to get a quick answer is to provide a failing test case, by forking the following fiddle for example.

Expected behaviour

Setup

• OS:
• browser:
• socket.io version:

Other information (e.g. stacktraces, related issues, suggestions how to fix)

[jcc10]

I would like to add that the following on the README.md

<script src="/socket.io/socket.io.js"></script>
<script>
  var socket = io('http://localhost');
  socket.on('connect', function(){});
  socket.on('event', function(data){});
  socket.on('disconnect', function(){});
</script>

// with ES6 import
import io from 'socket.io-client';

const socket = io('http://localhost');

Is misleading since it makes it look like you can use ES6 import on the client-side. Which you can't.

[zevero]

I was fooled as well. I do not always want to use webpack or similar.

ES6 imports are nothing new any more. Please make it work!

Many projects have a dedicated *.module.js which can be imported!

[jcc10]

just adding on that .mjs is the preferred file type for ES6 modules.

[chase-moskal]

hello, i was very disappointed to see that socket.io doesn't actually support clientside es modules

this is a significant pain

the documentation seems to be under the false impression that socket.io does support clientside es modules, but when you try to load it, the browser chokes when it find that the wrapper.mjs merely re-exports a file which is actually using require, and the whole thing fails

#1378 is a possible duplicate

[darrachequesne]

@chase-moskal thanks for the heads-up! I'm digging into this.

[darrachequesne]

Done! An ESM bundle is now provided:

<script type="module">
  import { io } from "https://cdn.socket.io/4.3.0/socket.io.esm.min.js";

  const socket = io();

  socket.emit("hello", "world");
</script>

Release notes: https://github.com/socketio/socket.io-client/releases/tag/4.3.0