use Modern::Perl; package My::Base; use Moose; has 'attr' => (is => 'rw', isa => 'Str', required => 1); around 'attr' => sub { my $orig = shift; my $self = shift; say "I get around..."; return $self->$orig() unless @_; }; package My::Derived; use Moose; extends 'My::Base'; has '+attr' => (required => 0, lazy_build => 1); sub _build_attr { return "default value"; } package My::Inherited; use Moose; extends 'My::Base'; package main; use Test::More; use Test::Exception; use Test::More::Diagnostic; plan tests => 8; my $base = new_ok('My::Base' => [attr => 'constructor value']); cmp_ok($base->attr, 'eq', "constructor value", 'base is correct'); lives_ok {My::Derived->new()} q/derived doesn't require 'attr' at construction/; my $der = new_ok('My::Derived'); cmp_ok($der->attr, 'eq', 'default value', 'derived is correct'); throws_ok {My::Base->new()} qr/Attribute \(attr\) is required/, q/inherited requires 'attr' at construction/;