gistfile1.pl

use strict;
use warnings;

use Test::More;

package Foo;
use Moose;
use MooseX::UndefTolerant;
use MooseX::Types::Moose qw/ Str /;

has 'bar' => (
    isa           => Str,
    is            => 'rw',
    required      => 0,
    default       => 'baz',
);

__PACKAGE__->meta->make_immutable;

1;

package main;

my $foo = Foo->new( bar => undef );
is ( $foo->bar, 'baz', 'does the default value get set when passing undef in the constructor and make_immutable is set' );

done_testing;