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#!/usr/bin/perl
use strict;
use warnings;
use Test::More tests => 20;
use Test::Exception;
BEGIN {
use_ok('Class::MOP');
}
{
package BankAccount;
use strict;
use warnings;
use metaclass;
use Carp 'confess';
BankAccount->meta->add_attribute('$:balance' => (
accessor => 'balance',
init_arg => 'balance',
default => 0
));
sub new { (shift)->meta->new_object(@_) }
sub deposit {
my ($self, $amount) = @_;
$self->balance($self->balance + $amount);
}
sub withdraw {
my ($self, $amount) = @_;
my $current_balance = $self->balance();
($current_balance >= $amount)
|| confess "Account overdrawn";
$self->balance($current_balance - $amount);
}
package CheckingAccount;
use strict;
use warnings;
use metaclass;
use base 'BankAccount';
CheckingAccount->meta->add_attribute('$:overdraft_account' => (
accessor => 'overdraft_account',
init_arg => 'overdraft',
));
CheckingAccount->meta->add_before_method_modifier('withdraw' => sub {
my ($self, $amount) = @_;
my $overdraft_amount = $amount - $self->balance();
if ($overdraft_amount > 0) {
$self->overdraft_account->withdraw($overdraft_amount);
$self->deposit($overdraft_amount);
}
});
::ok(CheckingAccount->meta->has_method('withdraw'), '... checking account now has a withdraw method');
::isa_ok(CheckingAccount->meta->get_method('withdraw'), 'Class::MOP::Method::Wrapped');
::isa_ok(BankAccount->meta->get_method('withdraw'), 'Class::MOP::Method');
}
my $savings_account = BankAccount->new(balance => 250);
isa_ok($savings_account, 'BankAccount');
is($savings_account->balance, 250, '... got the right savings balance');
lives_ok {
$savings_account->withdraw(50);
} '... withdrew from savings successfully';
is($savings_account->balance, 200, '... got the right savings balance after withdrawl');
dies_ok {
$savings_account->withdraw(250);
} '... could not withdraw from savings successfully';
$savings_account->deposit(150);
is($savings_account->balance, 350, '... got the right savings balance after deposit');
my $checking_account = CheckingAccount->new(
balance => 100,
overdraft => $savings_account
);
isa_ok($checking_account, 'CheckingAccount');
isa_ok($checking_account, 'BankAccount');
is($checking_account->overdraft_account, $savings_account, '... got the right overdraft account');
is($checking_account->balance, 100, '... got the right checkings balance');
lives_ok {
$checking_account->withdraw(50);
} '... withdrew from checking successfully';
is($checking_account->balance, 50, '... got the right checkings balance after withdrawl');
is($savings_account->balance, 350, '... got the right savings balance after checking withdrawl (no overdraft)');
lives_ok {
$checking_account->withdraw(200);
} '... withdrew from checking successfully';
is($checking_account->balance, 0, '... got the right checkings balance after withdrawl');
is($savings_account->balance, 200, '... got the right savings balance after overdraft withdrawl');
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