[2.x] [Webpack config] Code splitting fails for external npm modules

[rafaucau]

Current Behavior

When using dynamic imports for an external NPM module (e.g., import('sortablejs')), the generated chunk URL is incorrect. Flarum attempts to load the file from assets/forum/sortablejs.js instead of the extension's directory (e.g., assets/js/your-extension/forum/sortablejs.js), resulting in a 404 error.

Steps to Reproduce

1. In a Flarum extension, dynamically import an external npm package (e.g., import('sortablejs')).
2. Build the extension.
3. Trigger the dynamic import in the browser.
4. Check the network tab: Flarum tries to load assets/forum/sortable.js, which returns a 404.

Expected Behavior

Flarum should load the chunk from the extension's own assets directory (e.g., assets/js/your-extension/forum/sortablejs.js).

Screenshots

No response

Environment

• Flarum version: 2.0.0-rc.1

Output of php flarum info

No response

Possible Solution

A workaround is to create a local wrapper file inside the extension's src/ directory (e.g., src/forum/wrapper.js containing import sortablejs from 'sortablejs'; export default sortablejs;) and import that local file instead.

Additional Context

No response