I am attempting to create a subtheme using showcase_lite as a base theme. For now there will be mostly just CSS alterations in the subtheme.
To start, I created just an .info.yml file to start with:
name: My Subtheme type: theme description: 'Subtheme for testing' core: 8.x base theme: showcase_lite
Most inheritance works fine (CSS / JS / Twig), but it seems that the preprocess functions in the base .theme file are not called anymore. I am talking about _preprocess_html() for example.
Is this expected behaviour? If so, how could I have these be called from my own theme, without copypasting them all?