Thank you for pointing that out to me. I changed the last lines of the subroutine to include tobyink's suggestion of croak above in Re: short sorts. So now I have a more explicit conditional just to keep things tidy. Thanks! :)

  if ($type) {
    croak "$type is not supported" if !exists $sorts{$type};
    return $sorts{$type}->($a,$b);
  }
  else {
    my $random_sort = (keys %sorts)[rand (keys %sorts)];
    return $sorts{$random_sort}->($a,$b);
  }
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Update

Since the random sort is not acting as I expected, I decided to just let the subroutine die there.

  if ($type) {
    croak "$type is not supported" if !exists $sorts{$type};
    return $sorts{$type}->($a,$b);
  }
  else {
    die "A sort type was not selected.";
  }
[download]