Warning by using @mattermost/client in ESM

[Lyokolux]

Though Mattermost is usable, I get the warning :

@mattermost/client doesn't appear to be written in CJS, but also doesn't appear to be a valid ES module (i.e. it doesn't have "type": "module" or an .mjs extension for the entry point). Please contact the package author to fix.

A "type": "module" in the package.json is also used.

[Marthym]

Hi, thank for the warning, can you please give us more details on how to reproduce ?
The node version ?
...

[Lyokolux]

Node version: 16.13.2

In my project, I use import { Client4 } from '@mattermost/client' with this warning only.

Reproduction can be found while using Nuxt 3: https://stackblitz.com/edit/nuxt-starter-m68mre?file=server/mattermost.ts
This one raises an error on Stackblitz:

import pkg from 'file:///home/projects/nuxt-starter-m68mre/node_modules/@mattermost/client/lib/index.js';
const { Client4 } = pkg;

import { Client4 } from 'node_modules/@mattermost/client/lib/index.js';
^^^^^^^
SyntaxError: Named export 'Client4' not found. The requested module 'node_modules/@mattermost/client/lib/index.js' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from 'node_modules/@mattermost/client/lib/index.js';
const { Client4 } = pkg;

As the error says

The requested module 'node_modules/@mattermost/client/lib/index.js' is a CommonJS module

But I have read that the @mattermost/client package is already written in ESM. After an npm install, I can fix it for myself by adding type: "module" in the node_modules/@mattermost/client/package.json. I don't know if it will break on other projects though. I suppose not, as the entire package is already written in ESM.

[Marthym]

Thanks for that, we will try to fix that asap.

[Lyokolux]

Any updates?

[Marthym]

Topic still in progress, we don't have much time to work on it

If you know how to fix it, feel free to propose a PR, I'll quickly review it and merge it