#!./perl

use strict;
use warnings;

use Test::More tests => 7;

use List::Util qw(shuffle);

my @r;

@r = shuffle();
ok( !@r, 'no args');

@r = shuffle(9);
is( 0+@r, 1, '1 in 1 out');
is( $r[0], 9, 'one arg');

my @in = 1..100;
@r = shuffle(@in);
is( 0+@r, 0+@in, 'arg count');

isnt( "@r", "@in", 'result different to args');

my @s = sort { $a <=> $b } @r;
is( "@in", "@s", 'values');

{
  local $List::Util::RAND = sub { 4/10 }; # chosen by a fair die

  @r = shuffle(1..10);
  is_deeply(
    [ shuffle(1..10) ],
    [ shuffle(1..10) ],
    'rigged rand() yields predictable output'
  );
}