The contractor dealt with the specifics in this case, but the wiring for the lights was installed through the ceiling before the cabinets were installed. The wiring is brought down through the drywall and a hole in the top of the cabinet. There are a few options for lighting, including pucks and strips tucked in behind the front top frame. If you want the light to penetrate down the cabinet, install glass shelves.

Thank you so much! You confirmed what I was coming to a conclusion on.