how to delete multiple sub directories when file is empty

i have multiple sub directories in a directory . each directory contains a file named files.txt . i want to delete a sub directory which contains empty file names files.txt else not. i am using following script.

#!/bin/bash

    while [ -s */files.txt ]
    do
           line=pwd ;
           rm -r "$line" ;
    done

this is throwing error too many arguments . i also tried using

if [ -s */files.txt ]
then
       line=pwd
       rm -r "$line"
else
       echo "not empty"
fi