--- /dev/null
+use strict;
+use warnings;
+
+use Test::More tests=>15;
+use Moose::Util::TypeConstraints;
+use Moose::Meta::TypeConstraint::Parameterizable;
+use Moose;
+
+
+ok my $Optional = Moose::Meta::TypeConstraint::Parameterizable->new(
+ name => 'Optional',
+ package_defined_in => __PACKAGE__,
+ parent => find_type_constraint('Item'),
+ constraint => sub { 1 },
+ constraint_generator => sub {
+ my $type_parameter = shift;
+ my $check = $type_parameter->_compiled_type_constraint;
+ return sub {
+ my (@args) = @_;
+ if(exists($args[0])) {
+ ## If it exists, we need to validate it
+ $check->($args[0]);
+ } else {
+ ## But it's is okay if the value doesn't exists
+ return 1;
+ }
+ }
+ }
+);
+
+Moose::Util::TypeConstraints::add_parameterizable_type($Optional);
+use Data::Dump qw/dump/;
+
+ foreach my $type (Moose::Util::TypeConstraints::get_all_parameterizable_types()) {
+ if (my $constraint = $type->generate_constraint_for($Optional)) {
+ warn 'got this FARRRRRR..........................................';
+ }
+ }
+
+
+
+isa_ok $Optional, 'Moose::Meta::TypeConstraint::Parameterizable';
+
+ok my $int = find_type_constraint('Int') => 'Got Int';
+ok my $arrayref = find_type_constraint('ArrayRef[Int]') => 'Got ArrayRef[Int]';
+
+ok my $Optional_Int = $Optional->parameterize($int);
+ok my $Optional_ArrayRef = $Optional->parameterize($arrayref);
+
+
+ok $Optional_Int->check() => 'Optional is allowed to not exist';
+ok !$Optional_Int->check(undef) => 'Optional is NOT allowed to be undef';
+ok $Optional_Int->check(199) => 'Correctly validates 199';
+ok !$Optional_Int->check("a") => 'Correctly fails "a"';
+
+ok $Optional_ArrayRef->check() => 'Optional is allowed to not exist';
+ok !$Optional_ArrayRef->check(undef) => 'Optional is NOT allowed to be undef';
+ok $Optional_ArrayRef->check([1,2,3]) => 'Correctly validates [1,2,3]';
+ok !$Optional_ArrayRef->check("a") => 'Correctly fails "a"';
+ok !$Optional_ArrayRef->check(["a","b"]) => 'Correctly fails ["a","b"]';
\ No newline at end of file