my @lines = split /\n/, C4::Context->preference('ItemsDeniedRenewal')//'';

    my $denyingrules = get_yaml_pref_hash('ItemsDeniedRenewal');

    my $denyingrules;

    foreach my $line (@lines){

        my ($field,$array) = split /:/, $line;

        next if !$array;

        $field =~ s/^\s*|\s*$//g;

        $array =~ s/[ [\]\r]//g;

        my @array = split /,/, $array;

        @array = map { $_ eq '""' || $_ eq "''" ? '' : $_ } @array;

        @array = map { $_ eq 'NULL' ? undef : $_ } @array;

        $denyingrules->{$field} = \@array;

    }

- 

# This file is part of Koha.

#

# Copyright 2018 Koha Development Team

#

# Koha is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 3 of the License, or

# (at your option) any later version.

#

# Koha is distributed in the hope that it will be useful, but 

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with Koha; if not, see <http://www.gnu.org/licenses>.

use Modern::Perl;

use Test::More tests => 1;

use t::lib::Mocks;

use Koha::Util::SystemPreferences;

subtest 'get_yaml_pref_hash' => sub {

    plan tests => 1;

    t::lib::Mocks::mock_preference('ItemDeniedRenewal',q{

        nulled: [NULL,'']

        this: [just_that]

        multi_this: [that,another]

    });

    my $expected_hash = {

        nulled => [undef,""],

        this     => ['just_that'],

        multi_this => ['that','another'],

    };

    my $got_hash = get_yaml_pref_hash('ItemDeniedRenewal');

    is_deeply($got_hash,$expected_hash,"Pref fetched and converted correctly");

};