perl - Bread::Board 中的默认/可替换值

Question

我发现自己在许多测试中都实例化了相同的对象，所以我试图通过使用Bread::Board来替换这个常量设置。大多数时候，我希望依赖项具有相同的配置。但有时我可能希望使用非默认参数创建一个实例。在创建容器实例后，我还希望能够更改它。例如，我通常想要

my $c = Test::Container->new;

my $bar = $c->resolve( service => 'bar' ); # where bar depends on foo

但有时我真正需要的是

my $bar = $c->resolve( service => 'bar', {
              services => {
                foo => { init => 'arg' }
              }
          }

以便在创建 bar 的实例时以不同方式初始化服务 foo。

Answer 1

这是由Jesse Luehrs (Doy)在#moose 上提供给我的，看起来它会做我想做的事。

#!/usr/bin/env perl
use v5.14;
use strict;
use warnings;

package Container {
use Moose;
use Bread::Board;

extends 'Bread::Board::Container';

has '+name' => (default => 'Container');

sub BUILD {
    my $self = shift;
    container $self => as {
        service foo => (
            block => sub {
                my $s = shift;
                $s->param('foo_val');
            },
            parameters => {
                foo_val => { isa => 'Str' },
            },
        );
        service bar => (
            block => sub {
                my $s = shift;
                $s->param('foo')->inflate(foo_val => $s->param('foo_val')) . 'BAR';
            },
            dependencies => ['foo'],
            parameters => {
                foo_val => { isa => 'Str', default => 'FOO' },
            },
        );
    };
}
}

my $c = Container->new;
warn $c->resolve(service => 'bar');
warn $c->resolve(service => 'bar', parameters => { foo_val => 'baz' });