Using decorators to handle errors

lib/Zonemaster/Backend/DB/MySQL.pm

@@ -10,6 +10,7 @@ use DBI qw(:utils);
 use JSON::PP;
 
 use Zonemaster::Backend::Validator qw( untaint_ipv6_address );
+use Zonemaster::Backend::Errors;
 
 with 'Zonemaster::Backend::DB';
 
@@ -228,12 +229,14 @@ sub get_test_params {
 
     my ( $params_json ) = $self->dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
 
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $params_json;
+
     my $result;
     eval {
         $result = decode_json( $params_json );
     };
 
-    warn "decoding of params_json failed (testi_id: [$test_id]):".Dumper($params_json) if $@;
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } ) if $@;
 
     return decode_json( $params_json );
 }
@@ -249,8 +252,20 @@ sub test_results {
     my $result;
     my ( $hrefs ) = $self->dbh->selectall_hashref( "SELECT id, hash_id, CONVERT_TZ(`creation_time`, \@\@session.time_zone, '+00:00') AS creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
     $result            = $hrefs->{$test_id};
-    $result->{params}  = decode_json( $result->{params} );
-    $result->{results} = decode_json( $result->{results} );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $result;
+
+    eval {
+        $result->{params}  = decode_json( $result->{params} );
+
+        if (defined $result->{results}) {
+            $result->{results} = decode_json( $result->{results} );
+        } else {
+            $result->{results} = [];
+        }
+    };
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } ) if $@;
 
     return $result;
 }

lib/Zonemaster/Backend/DB/PostgreSQL.pm

@@ -10,6 +10,7 @@ use Encode;
 use JSON::PP;
 
 use Zonemaster::Backend::DB;
+use Zonemaster::Backend::Errors;
 
 with 'Zonemaster::Backend::DB';
 
@@ -207,8 +208,12 @@ sub get_test_params {
 
     my $dbh = $self->dbh;
     my ( $params_json ) = $dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $params_json;
+
     eval { $result = decode_json( encode_utf8( $params_json ) ); };
-    die "$@ \n" if $@;
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } ) if $@;
 
     return $result;
 }
@@ -222,27 +227,34 @@ sub test_results {
       if ( $results );
 
     my $result;
-    eval {
-        my ( $hrefs ) = $dbh->selectall_hashref( "SELECT id, hash_id, creation_time at time zone current_setting('TIMEZONE') at time zone 'UTC' as creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
-        $result            = $hrefs->{$test_id};
+    my ( $hrefs ) = $dbh->selectall_hashref( "SELECT id, hash_id, creation_time at time zone current_setting('TIMEZONE') at time zone 'UTC' as creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
+    $result = $hrefs->{$test_id};
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $result;
 
+    eval {
         # This workaround is needed to properly handle all versions of perl and the DBD::Pg module
         # More details in the zonemaster backend issue #570
         if (utf8::is_utf8($result->{params}) ) {
-                $result->{params}  = decode_json( encode_utf8($result->{params}) );
+            $result->{params}  = decode_json( encode_utf8($result->{params}) );
         }
         else {
-                $result->{params}  = decode_json( $result->{params} );
+            $result->{params}  = decode_json( $result->{params} );
         }
 
-        if (utf8::is_utf8($result->{results} ) ) {
+        if (defined $result->{results} ) {
+            if (utf8::is_utf8($result->{results} ) ) {
                 $result->{results}  = decode_json( encode_utf8($result->{results}) );
-        }
-        else {
+            }
+            else {
                 $result->{results}  = decode_json( $result->{results} );
+            }
+        } else {
+            $result->{results} = [];
         }
     };
-    die "$@ \n" if $@;
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id }) if $@;
 
     return $result;
 }

lib/Zonemaster/Backend/DB/SQLite.pm

@@ -11,6 +11,8 @@ use Digest::MD5 qw(md5_hex);
 use JSON::PP;
 use Log::Any qw( $log );
 
+use Zonemaster::Backend::Errors;
+
 with 'Zonemaster::Backend::DB';
 
 has 'dbh' => (
@@ -244,12 +246,14 @@ sub get_test_params {
 
     my ( $params_json ) = $self->dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
 
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $params_json;
+
     my $result;
     eval {
         $result = decode_json( $params_json );
     };
 
-    $log->warn( "decoding of params_json failed (test_id: [$test_id]):".Dumper($params_json) ) if $@;
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } ) if $@;
 
     return $result;
 }
@@ -265,8 +269,20 @@ sub test_results {
     my $result;
     my ( $hrefs ) = $self->dbh->selectall_hashref( "SELECT id, hash_id, creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
     $result            = $hrefs->{$test_id};
-    $result->{params}  = decode_json( $result->{params} );
-    $result->{results} = decode_json( $result->{results} );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } ) unless defined $result;
+
+    eval {
+        $result->{params}  = decode_json( $result->{params} );
+
+        if (defined $result->{results}) {
+            $result->{results} = decode_json( $result->{results} );
+        } else {
+            $result->{results} = [];
+        }
+    };
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } ) if $@;
 
     return $result;
 }

lib/Zonemaster/Backend/Errors.pm

@@ -0,0 +1,160 @@
+package Zonemaster::Backend::Error;
+use Moose;
+use Data::Dumper;
+
+
+has 'message' => (
+    is => 'rw',
+    isa => 'Str',
+    required => 1,
+);
+
+has 'code' => (
+    is => 'rw',
+    isa => 'Int',
+    required => 1,
+);
+
+has 'data' => (
+    is => 'rw',
+    isa => 'Any',
+    default => undef,
+);
+
+sub as_hash {
+    my $self = shift;
+    my $error = {
+        code => $self->code,
+        message => $self->message,
+        error => ref($self),
+    };
+    $error->{data} = $self->data if defined $self->data;
+    return $error;
+}
+
+sub as_string {
+    my $self = shift;
+    my $str = sprintf "%s (code %d)", $self->message, $self->code;
+    if (defined $self->data) {
+        $str .= sprintf "; Context: %s", $self->_data_dump;
+    }
+    return $str;
+}
+
+sub _data_dump {
+    my $self = shift;
+    local $Data::Dumper::Indent = 0;
+    local $Data::Dumper::Terse = 1;
+    my $data = Dumper($self->data);
+    $data =~ s/[\n\r]/ /g;
+    return $data ;
+}
+
+package Zonemaster::Backend::Error::Internal;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Internal server error'
+);
+
+has '+code' => (
+    default => -32603
+);
+
+has 'reason' => (
+    isa => 'Str',
+    is => 'rw',
+    initializer => 'reason',
+);
+
+has 'method' => (
+    is => 'rw',
+    isa => 'Str',
+    builder => '_build_method'
+);
+
+has 'id' => (
+    is => 'rw',
+    isa => 'Int',
+    default => 0,
+);
+
+sub _build_method {
+    my $s = 0;
+    while (my @c = caller($s)) {
+        $s ++;
+        last if $c[3] eq 'Moose::Object::new';
+    }
+    my @c = caller($s);
+    if ($c[3] =~ /^(.*)::handle_exception$/ ) {
+        @c = caller(++$s);
+    }
+
+    return $c[3];
+}
+
+around 'reason' => sub {
+    my $orig = shift;
+    my $self = shift;
+
+    my ( $value, $setter, $attr ) = @_;
+
+    # reader
+    return $self->$orig if not $value;
+
+    # trim new lines
+    $value =~ s/\n/ /g;
+    $value =~ s/^\s+|\s+$//g;
+
+    # initializer
+    return $setter->($value) if $setter;
+
+    # writer
+    $self->$orig($value);
+};
+
+around 'as_hash' => sub {
+    my $orig = shift;
+    my $self = shift;
+
+    my $href = $self->$orig;
+
+    $href->{exception_id} = $self->id;
+    $href->{reason} = $self->reason;
+    $href->{method} = $self->method;
+
+    return $href;
+};
+
+
+sub as_string {
+    my $self = shift;
+    my $str = sprintf "Internal error %0.3d (%s): Unexpected error in the `%s` method: [%s]", $self->id, ref($self), $self->method, $self->reason;
+    if (defined $self->data) {
+        $str .= sprintf "; Context: %s", $self->_data_dump;
+    }
+    return $str;
+}
+
+
+package Zonemaster::Backend::Error::ResourceNotFound;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Resource not found'
+);
+
+has '+code' => (
+    default => -32000
+);
+
+package Zonemaster::Backend::Error::JsonError;
+use Moose;
+
+extends 'Zonemaster::Backend::Error::Internal';
+
+1;