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

Inizia eseguendo l’esempio fornito css2json-loader_sass_issue.zip con le versioni di NativeScript indicate e la pipeline dart-sass. Ispeziona bundle.js intorno al codice generato da css2json e confronta il risultato con css-loader; il lavoro è completato quando l’app di esempio si avvia senza il testo undefined né arrestarsi in modo anomalo.