TS2722

TS2722: Cannot invoke an object which is possibly 'undefined'.

createEffect(() => {  
  if (drawerIsOpen() && viewportSizeProvider.viewPortIsLessThan1210) {  
    createPreventScroll();  
    incrementPreventScrollLayerCount();  
  }  
});

Just add a ! if you’re sure func is never undefined

createEffect(() => {  
  if (drawerIsOpen() && viewportSizeProvider.viewPortIsLessThan1210) {  
    createPreventScroll();  
    incrementPreventScrollLayerCount!();   // <---  !
  }  
});