小编j1n*_*3l0的帖子

我继承了以下针对Type-Tiny-1.004004编写的代码：

package Company::Types;

use Type::Library -base, -declare => qw< TruncatedString >;
use Type::Utils -all;

declare TruncatedString, as Str,
    where { length $_ },
    inline_as {
        my ($constraint, $varname) = @_;
        
        return sprintf ( '!defined %s or %s',
            $varname,
            $constraint->parent->inline_check($varname),
        );
    },
    constraint_generator => sub {
        my ($max) = @_;
        die q{Max length must be positive!} unless int($max) > 0;
        return sub { 
            (length $_) <= $max;
        };
    },
    inline_generator => sub {
        my ($max) = @_;
        return sub …

我正在尝试研究如何使用Test2::V0测试可选的哈希字段。我目前有以下几点：

use 5.016;
use Test2::V0;

subtest 'optional fields in a hash' => sub {
    my $check = hash {
        field foo => qr/^[0-9]+$/;
        field bar => qr/^[a-zA-Z]+$/; # this field is optional
    };

    like(
        { foo => 1 },
        $check,
        'should pass when optional field is omitted',
    );

    like(
        { foo => 2, bar => 'a' },
        $check,
        'should pass when optional field is provided',
    );
};

done_testing;

现在，如果我放弃对可选字段的检查：

my $check = hash {
    field foo => qr/^[0-9]+$/; …