sass-loader ignores import-only files

[jathak]

• Operating System: Debian Stretch
• Node Version: 13.5.0
• NPM Version: 6.13.4
• webpack Version: 4.41.5
• sass-loader Version: 8.0.0
• Sass version: Dart Sass 1.24.1

Expected Behavior

@import rules should load the import-only file if one exists, instead of the regular file (as is the case for @use and @forward rules).

This behavior is necessary to allow for incremental migration to the Sass module system, as libraries use import-only files to preserve manual member prefixes for @import users while removing them for users who migrate to the module system.

Actual Behavior

@import rules always load the regular file, even if an import-only file exists. The code below works with Dart Sass on its own, but errors when run through sass-loader.

Code

// style.scss
@import "dependency";

a {
  color: $dep-color;
}

// _dependency.scss
$color: blue;

// _dependency.import.scss
@forward "dependency" as dep-*;

[jathak]

Upon further investigation, it looks like this is actually a bug in Sass itself, so closing this issue