Missing "stylePreprocessorOptions" field for Vitest config (Library Builder)

[ms-dosx86]

Which @angular/* package(s) are the source of the bug?

Don't known / other

Is this a regression?

No

Description

I wanted to migrate from Karma to experimental Vitest test runner but unfortunately couldn't make it due to lack of "stylePreprocessorOptions" property in configuration file. Is it just missing or are there other ways to include paths to shorten SCSS imports?

Here is my setup

            "stylePreprocessorOptions": {
              "includePaths": [
                "projects/ui-kit/styles/",
                "projects/ui-kit/styles/components/"
              ]
            }

And in components I would

@use 'mixins' as mixins;

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 20.0.2
Node: 22.12.0
Package Manager: npm 10.9.0
OS: darwin arm64

Angular: 20.0.3
... animations, cdk, common, compiler, compiler-cli, core, forms
... language-service, localize, platform-browser
... platform-browser-dynamic, platform-server, router

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.2000.2
@angular-devkit/core         20.0.2
@angular-devkit/schematics   20.0.2
@angular/build               20.0.2
@angular/cli                 20.0.2
@angular/ssr                 20.0.2
@schematics/angular          20.0.2
ng-packagr                   20.0.0
rxjs                         7.8.1
typescript                   5.8.3
zone.js                      0.15.0

Anything else?

No response

[alan-agius4]

The stylePreprocessorOptions options are inhered from the build target.

[ms-dosx86]

Thank you. Good to know

[ms-dosx86]

@alan-agius4 I just realised that in my case the project is a library and angular doesn't allow to set "stylePreprocessorOptions" in the build target's options. AFAIK the official way to do this is to use "styleIncludePaths" in ng-package.json. But this doesn't work in unit testing so that was the reason why I used "stylePreprocessorOptions" specifically for test options. So how else do we do it or am I missing something?

[alan-agius4]

You're right, the builder options for libraries aren't inherited, and this is an area that still needs improvement.