Is there a way to automatically hide empty folders either directly or by an add-on?

I would like to lessen the clutter in the main page such that I can hide folders as desired. It seems that this is already done automatically to an extent by hiding mail folder groups which have had their sub-folders redirected to another group(s). Hiding folders when they are empty (not needed to be shown) would be one way to do this. For example, it is not necessary to show the "trash" folder after it has been emptied.

Thanks.