use strict;
use File::Spec::Functions;
use Test::More tests => 5;

my @file = do {
	opendir my $dh, curdir or die "$!";
	readdir $dh;
};

sub check(&) { not grep $_ eq updir, shift->( @file ) }

;ok check { sort    no_upwards  @_     }
;ok check { sort    no_upwards( @_ )   }
;ok check { sort  ( no_upwards  @_ )   }
;ok check { sort  ( no_upwards( @_ ) ) }
;ok check { sort +( no_upwards  @_ )   }

=begin output

1..5
not ok 1
#   Failed test at t.pl line 13.
not ok 2
#   Failed test at t.pl line 14.
not ok 3
#   Failed test at t.pl line 15.
ok 4
ok 5
# Looks like you failed 3 tests of 5.