File Coverage

blib/lib/JSON/MergePatch.pm

Criterion	Covered	Total	%
statement	58	58	100.0
branch	29	30	96.6
condition	14	18	77.7
subroutine	10	10	100.0
pod	4	4	100.0
total	115	120	95.8

package JSON::MergePatch;
use 5.008001;
use strict;
use warnings;

our $VERSION = "0.01";

use parent 'Exporter';
use JSON qw/encode_json decode_json/;
use List::MoreUtils qw/uniq/;

our @EXPORT = qw/json_merge_patch json_merge_diff/;


sub patch {
    my ($class, $target, $patch, $opt) = @_;
    if (defined $target && !$opt->{repeat}) {
        $target = decode_json($target);
    }

    if (ref $patch eq 'HASH') {
        unless (ref $target eq 'HASH') {
            $target = +{};
        }

        for my $key (keys $patch) {
            if (defined $patch->{$key}) {
                $target->{$key} = __PACKAGE__->patch($target->{$key}, $patch->{$key}, {repeat => 1});
            }
            else {
                if (exists $target->{$key}) {
                    delete $target->{$key};
                }
            }
        }
        return ref $target ? encode_json($target) : $target;
    }

    return ref $patch ? encode_json($patch) : $patch;
}

sub diff {
    my ($class, $source, $target, $opt) = @_;

    my ($decoded_source, $decoded_target);
    if ($opt->{repeat}) {
        $decoded_source = $source;
        $decoded_target = $target;
    } else {
        $decoded_source = eval {
            decode_json($source);
        };
        if ($@) {
            return $source;
        }

        $decoded_target = eval {
            decode_json($target);
        };
        if ($@) {
            return $decoded_source;
        }
    }

    if (ref $decoded_source eq 'ARRAY') {
        return $decoded_source;
    }

    if (ref $decoded_source eq 'HASH') {
        if (ref $decoded_target eq 'HASH') {
            for my $key (uniq (keys $decoded_target, keys $decoded_source)) {
                $decoded_source->{$key} = __PACKAGE__->diff($decoded_source->{$key}, $decoded_target->{$key}, {repeat => 1});

                if (exists $decoded_target->{$key} && exists $decoded_source->{$key}) {
                    if (
                        (!defined $decoded_target->{$key} && !defined $decoded_source->{$key}) ||
                        (defined $decoded_target->{$key} && defined $decoded_source->{$key} && $decoded_target->{$key} eq $decoded_source->{$key})
                    ) {
                        delete $decoded_source->{$key};
                    }
                }
            }

            return $decoded_source;
        }
        else {
            return $decoded_source;
        }
    }

    return $decoded_source;
}

sub json_merge_patch {
    __PACKAGE__->patch(@_);
}

sub json_merge_diff {
    __PACKAGE__->diff(@_);
}


1;
__END__