I would rethink this

# show no warnings about recursion (we know what we do  )
no warnings "recursion";
[download]

You can replace that with

use File::Find::Rule;
my @jsfiles = find( file => name => qr{\.js$} => in => $searchdir );

Or even the iterator version (if you have thousands of files), example in Re^2: Write to existing file with character insert