With "modern" API, the `importer` behaves strangely with nested imports

[adrienharnay]

Modification Proposal

I believe there are some quirks in the current importer implementation that limit possible use cases. One of these use cases is to import JSON files with sass or embedded-sass implementations.

Expected Behavior / Situation

Here is a minimal reproduction with steps to understand the limitations and changes needed to make the importer work.

From the README:

• That the // No need to pass loadPaths, because modern API handle them itself comment is not 100% right.
• That without restrictions: [/\.(((sa|sc|c)ss)|json)$/i],, the JSON file won't be picked up by the webpack resolver and thus it won't load.
• That we need to re-implement our importer logic in the sass-loader load function because it won't call our importer (?).

I remain available to exchange on the topic, having spent a few hours browsing and debugging the code.

Please paste the results of npx webpack-cli info here, and mention other relevant information

System:
    OS: macOS 14.6.1
    CPU: (8) arm64 Apple M1 Pro
    Memory: 57.83 MB / 16.00 GB
  Binaries:
    Node: 22.9.0 - /usr/local/bin/node
    Yarn: 4.5.0 - /opt/homebrew/bin/yarn
    npm: 10.8.3 - /usr/local/bin/npm
  Browsers:
    Chrome: 129.0.6668.100
    Safari: 17.6
  Packages:
    css-loader: ^7.1.2 => 7.1.2 
    sass-loader: ^16.0.2 => 16.0.2 
    style-loader: ^4.0.0 => 4.0.0 
    webpack: ^5.95.0 => 5.95.0 
    webpack-cli: ^5.1.4 => 5.1.4 

Thanks in advance!