Using sass (dart-sass) with css2json-loader acts weird and crashes the app

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.4.x (probably happens on older)
• Cross-platform modules: 6.4.x (same)
• Android Runtime: 6.4.x
• iOS Runtime: 6.4.x

Describe the bug
An app with SCSS that is handled with sass implementation (dart-sass) and then served through css2json-loader produces code in the form of "undefinedundefined" inside bundle.js, just after the css2json produced code and app crashes on startup. Removing the css2json-loader and using css-loader works normal. Changing Webpack to 4.40.x produces several pages filled with "undefinedundefinedundefined...".

To Reproduce
Use the provided project and try to run it.

Expected behavior
To run.

Sample project
css2json-loader_sass_issue.zip

Commencez par exécuter l’exemple fourni css2json-loader_sass_issue.zip avec les versions de NativeScript indiquées et le pipeline dart-sass. Inspectez bundle.js autour du code généré par css2json et comparez le résultat avec css-loader ; c’est terminé lorsque l’application d’exemple démarre sans le texte undefined ni plantage.