CPAN::Groonga

use strict;
use warnings;
use Test::More;

use_ok 'Data::Object::Undef';
# deprecated
# can_ok 'Data::Object::Undef', 'defined';

use Scalar::Util 'refaddr';

subtest 'test the defined method' => sub {
  my $undef   = Data::Object::Undef->new(undef);
  my $defined = $undef->defined;

  isnt refaddr($undef), refaddr($defined);
  is $defined, 0;

  isa_ok $undef,   'Data::Object::Undef';
  isa_ok $defined, 'Data::Object::Number';

  $defined = $undef->defined(9876543210);

  isnt refaddr($undef), refaddr($defined);
  is $defined, 0;

  isa_ok $undef,   'Data::Object::Undef';
  isa_ok $defined, 'Data::Object::Number';
};

ok 1 and done_testing;