use strict;
use warnings;
use Test::More;
use Test::Fatal;
{
    package HTTPHeader;
    use Moose;
    has 'array' => (is => 'ro');
    has 'hash'  => (is => 'ro');
}
{
    package Request;
    use Moose;
    use Moose::Util::TypeConstraints;
    subtype 'Header'
        => as 'Object'
        => where { $_->isa('HTTPHeader') };
    coerce 'Header'
        => from 'ArrayRef'
            => via { HTTPHeader->new(array => $_[0]) }
        => from 'HashRef'
            => via { HTTPHeader->new(hash => $_[0]) };
    has 'headers'  => (
        is      => 'rw',
        isa     => 'Header',
        coerce  => 1,
        lazy    => 1,
        default => sub { [ 'content-type', 'text/html' ] }
    );
}
my $r = Request->new;
isa_ok($r, 'Request');
is( exception {
    $r->headers;
}, undef, '... this coerces and passes the type constraint even with lazy' );
done_testing;