feat: harden xml parsing to avoid uncaught errors

src/BusProNet/XmlParser/AbstractParser.php

@@ -47,4 +47,23 @@ abstract class AbstractParser
 
         return $this->stringToArray($node->text(), $separator);
     }
+
+    protected function getAttrOrNullValue(Crawler $node, string $attribute): ?string
+    {
+        if (0 === $node->count()) {
+            return null;
+        }
+
+        return $node->attr($attribute);
+    }
+
+    protected function getRequiredAttrValue(Crawler $node, string $attribute, string $context): string
+    {
+        $value = $this->getAttrOrNullValue($node, $attribute);
+        if (null === $value || '' === trim($value)) {
+            throw new \InvalidArgumentException(sprintf('Missing required attribute "%s" in %s.', $attribute, $context));
+        }
+
+        return $value;
+    }
 }

src/BusProNet/XmlParser/ApiResponseParser.php

@@ -25,11 +25,15 @@ class ApiResponseParser extends AbstractParser
 
         $resultNode = $crawler->filterXPath('//ergebnis');
 
+        try {
             switch ($responseType) {
                 case ApiClient::TYPE_NOTIFICATION:
                     return (new NotificationParser())->parse($crawler);
                 case ApiClient::TYPE_CUSTOMER_DATA:
-                $subType = $resultNode->filterXPath('//art')->text();
+                    $subType = $this->getStringOrNullValue($resultNode->filterXPath('//art'));
+                    if (null === $subType || '' === $subType) {
+                        throw new ResponseParserException('Unable to determine customer data subtype from XML response');
+                    }
 
                     switch ($subType) {
                         case 'Adressdaten':
@@ -68,6 +72,10 @@ class ApiResponseParser extends AbstractParser
                 case ApiClient::TYPE_PRODUCT_DATA:
                     $travelNode = $crawler->filterXPath('//reise/termin');
 
+                    if (0 === $travelNode->count()) {
+                        throw new ResponseParserException('No travel data node found in product data response');
+                    }
+
                     return (new TravelParser())->parse($travelNode->first(), ...$additionalArgs);
                 case ApiClient::TYPE_AGENCIES:
                     return (new AgencyParser())->parse($resultNode);
@@ -76,6 +84,9 @@ class ApiResponseParser extends AbstractParser
                 case ApiClient::TYPE_PROMO_VOUCHER:
                     return (new PromoVoucherParser())->parse($resultNode);
             }
+        } catch (\InvalidArgumentException $e) {
+            throw new ResponseParserException('Invalid XML response structure: '.$e->getMessage(), 0, $e);
+        }
 
         throw new ResponseParserException('Unable to parse XML response');
     }

src/BusProNet/XmlParser/BookingParser.php

@@ -40,10 +40,10 @@ class BookingParser extends AbstractParser
 
         $travelData = $node->filterXPath('//reise');
 
-        $booking->travelName = $travelData->attr('bezeichnung');
+        $booking->travelName = $this->getAttrOrNullValue($travelData, 'bezeichnung');
         $booking->dateId = $this->getIntOrNullValue($node->filterXPath('//idreise'));
-        $booking->travelCode = $travelData->attr('code');
+        $booking->travelCode = $this->getAttrOrNullValue($travelData, 'code');
-        $booking->travelDate = $this->stringToDate($travelData->attr('termin'));
+        $booking->travelDate = $this->stringToDate($this->getAttrOrNullValue($travelData, 'termin'));
 
         $booking->hotelId = $this->getIntOrNullValue($node->filterXPath('//idpartner'));
         $booking->hotelName = $this->getStringOrNullValue($node->filterXPath('//partner'));
@@ -56,17 +56,17 @@ class BookingParser extends AbstractParser
         $booking->participants = $this->parseParticipants($node->filterXPath('//teilnehmerliste/teilnehmer'));
 
         $paymentData = $node->filterXPath('//zahlung');
-        $booking->paymentId = (int) $paymentData->attr('idzahlungsart');
+        $booking->paymentId = $this->getAttrOrNullValue($paymentData, 'idzahlungsart');
-        $booking->paymentLabel = $paymentData->attr('bezeichnung');
+        $booking->paymentLabel = $this->getAttrOrNullValue($paymentData, 'bezeichnung');
-        $booking->paymentType = $paymentData->attr('art');
+        $booking->paymentType = $this->getAttrOrNullValue($paymentData, 'art');
 
         if (0 < $paymentData->children()->count()) {
             $bankDataNode = $paymentData->children()->first();
             $bankAccount = new BankAccount();
-            $bankAccount->iban = $bankDataNode->attr('iban');
+            $bankAccount->iban = $this->getAttrOrNullValue($bankDataNode, 'iban');
-            $bankAccount->bic = $bankDataNode->attr('bic');
+            $bankAccount->bic = $this->getAttrOrNullValue($bankDataNode, 'bic');
-            $bankAccount->bankName = $bankDataNode->attr('kreditinstitut');
+            $bankAccount->bankName = $this->getAttrOrNullValue($bankDataNode, 'kreditinstitut');
-            $bankAccount->holder = $bankDataNode->attr('kontoinhaber');
+            $bankAccount->holder = $this->getAttrOrNullValue($bankDataNode, 'kontoinhaber');
             $booking->bankAccount = $bankAccount;
         }
 
@@ -117,7 +117,12 @@ class BookingParser extends AbstractParser
         $participants = [];
 
         $node->each(function (Crawler $node) use (&$participants) {
-            $id = (int) $node->attr('id');
+            $id = (int) ($this->getAttrOrNullValue($node, 'id') ?? 0);
+
+            if ($id <= 0) {
+                return;
+            }
+
             $participants[$id - 1] = $this->parsePersonalData($node);
         });
 

src/BusProNet/XmlParser/BookingResponseParser.php

@@ -32,7 +32,11 @@ class BookingResponseParser extends AbstractParser
 {
     public function parse(Crawler $node): BookingResponse
     {
-        $status = $node->filterXPath('//buchung')->text();
+        $status = $this->getStringOrNullValue($node->filterXPath('//buchung'));
+        if (null === $status || '' === $status) {
+            throw new \InvalidArgumentException('Missing required booking status in booking response.');
+        }
+
         $bookingNumber = $this->getIntOrNullValue($node->filterXPath('//vorgang'));
         $totalPrice = $this->getFloatOrNullValue($node->filterXPath('//gesamtpreis'));
         $message = $this->getStringOrNullValue($node->filterXPath('//hinweis'));
@@ -60,18 +64,24 @@ class BookingResponseParser extends AbstractParser
         $priceItems = [];
 
         $node->filterXPath('//preise/preis')->each(function (Crawler $priceNode) use (&$priceItems): void {
+            $position = (int) $this->getRequiredAttrValue($priceNode, 'position', 'booking response price item');
+            $type = $this->getRequiredAttrValue($priceNode, 'art', 'booking response price item');
+            $label = $this->getRequiredAttrValue($priceNode, 'bezeichnung', 'booking response price item');
+            $unitPrice = $this->stringToFloat($this->getRequiredAttrValue($priceNode, 'preis', 'booking response price item'));
+            $totalPrice = $this->stringToFloat($this->getRequiredAttrValue($priceNode, 'gesamtpreis', 'booking response price item'));
+
             $priceItems[] = new PriceItem(
-                position: (int) $priceNode->attr('position'),
+                position: $position,
-                type: $priceNode->attr('art'),
+                type: $type,
-                subType: $priceNode->attr('unterart'),
+                subType: $this->getAttrOrNullValue($priceNode, 'unterart'),
-                label: $priceNode->attr('bezeichnung'),
+                label: $label,
-                dateFrom: $priceNode->attr('terminvon'),
+                dateFrom: $this->getAttrOrNullValue($priceNode, 'terminvon'),
-                dateTo: $priceNode->attr('terminbis'),
+                dateTo: $this->getAttrOrNullValue($priceNode, 'terminbis'),
-                quantity: (int) $priceNode->attr('anzahl'),
+                quantity: (int) ($this->getAttrOrNullValue($priceNode, 'anzahl') ?? 0),
-                assignment: $priceNode->attr('zuordnung'),
+                assignment: $this->getAttrOrNullValue($priceNode, 'zuordnung'),
-                unitPrice: $this->stringToFloat($priceNode->attr('preis')),
+                unitPrice: $unitPrice,
-                totalPrice: $this->stringToFloat($priceNode->attr('gesamtpreis')),
+                totalPrice: $totalPrice,
-                id: $priceNode->attr('id')
+                id: $this->getAttrOrNullValue($priceNode, 'id')
             );
         });
 
@@ -94,25 +104,26 @@ class BookingResponseParser extends AbstractParser
         $finalPaymentAmount = null;
         $finalPaymentDate = null;
 
-        $depositNode = $paymentNode->filterXPath('//anzahlung');
+        $depositNode = $paymentNode->filterXPath('.//anzahlung');
         if ($depositNode->count() > 0) {
-            $depositAmount = $this->stringToFloat($depositNode->attr('betrag'));
+            $depositAmount = $this->stringToFloat($this->getAttrOrNullValue($depositNode, 'betrag'));
-            $depositDate = $depositNode->attr('termin');
+            $depositDate = $this->getAttrOrNullValue($depositNode, 'termin');
         }
 
-        $finalPaymentNode = $paymentNode->filterXPath('//restzahlung');
+        $finalPaymentNode = $paymentNode->filterXPath('.//restzahlung');
         if ($finalPaymentNode->count() > 0) {
-            $finalPaymentAmount = $this->stringToFloat($finalPaymentNode->attr('betrag'));
+            $finalPaymentAmount = $this->stringToFloat($this->getAttrOrNullValue($finalPaymentNode, 'betrag'));
-            $finalPaymentDate = $finalPaymentNode->attr('termin');
+            $finalPaymentDate = $this->getAttrOrNullValue($finalPaymentNode, 'termin');
         }
 
         // Parse purchase vouchers (kaufgutschein elements)
         $appliedPurchaseVouchers = [];
-        $voucherNodes = $paymentNode->filterXPath('//kaufgutschein');
+        $voucherNodes = $paymentNode->filterXPath('.//kaufgutschein');
         $voucherNodes->each(function (Crawler $voucherNode) use (&$appliedPurchaseVouchers): void {
+            $amount = $this->getAttrOrNullValue($voucherNode, 'betrag');
             $appliedPurchaseVouchers[] = [
-                'nummer' => $voucherNode->attr('nummer') ?? '',
+                'nummer' => $this->getAttrOrNullValue($voucherNode, 'nummer') ?? '',
-                'betrag' => $this->stringToFloat($voucherNode->attr('betrag')),
+                'betrag' => $this->stringToFloat($amount),
             ];
         });
 

src/BusProNet/XmlParser/BookingUpdateParser.php

@@ -9,10 +9,12 @@ class BookingUpdateParser extends AbstractParser
 {
     public function parse(Crawler $node): BookingUpdate
     {
+        $changeStatus = $this->getStringOrNullValue($node->filterXPath('//aenderung'));
+
         $bookingUpdate = new BookingUpdate();
-        $bookingUpdate->valid = 'möglich' === $node->filterXPath('//aenderung')->text();
+        $bookingUpdate->valid = 'möglich' === $changeStatus;
-        $bookingUpdate->success = 'erfolgt' === $node->filterXPath('//aenderung')->text();
+        $bookingUpdate->success = 'erfolgt' === $changeStatus;
-        $bookingUpdate->status = $node->filterXPath('//status')->text();
+        $bookingUpdate->status = $this->getStringOrNullValue($node->filterXPath('//status'));
 
         return $bookingUpdate;
     }

src/BusProNet/XmlParser/ContactFormResponseParser.php

@@ -11,8 +11,12 @@ class ContactFormResponseParser extends AbstractParser
 {
     public function parse(Crawler $node): RegistrationResponse
     {
-        $addressId = (int) $node->filterXPath('//idadresse')->text();
+        $addressId = $this->getIntOrNullValue($node->filterXPath('//idadresse'));
-        $personId = (int) $node->filterXPath('//idperson')->text();
+        $personId = $this->getIntOrNullValue($node->filterXPath('//idperson'));
+        if (null === $addressId || null === $personId) {
+            throw new \InvalidArgumentException('Missing required idadresse or idperson in contact form response.');
+        }
+
         $isNewRecord = $this->getBoolValue($node->filterXPath('//neuanlage'));
 
         return new RegistrationResponse(

src/BusProNet/XmlParser/DocumentsParser.php

@@ -44,15 +44,29 @@ class DocumentsParser
 
     private function decode(Crawler $node): string
     {
-        [, $pdfData] = explode(',', $node->text());
+        if (0 === $node->count()) {
+            throw new \InvalidArgumentException('Missing PDF node in document response.');
+        }
+
+        $parts = explode(',', $node->text(), 2);
+        if (2 !== count($parts)) {
+            throw new \InvalidArgumentException('Invalid PDF payload in document response.');
+        }
+
+        [, $pdfData] = $parts;
 
         return base64_decode($pdfData);
     }
 
     private function getFileInfo(Crawler $node): array
     {
-        $pdfData = $this->decode($node->filterXPath('//pdf'));
+        $pdfData = $this->decode($node->filterXPath('.//pdf'));
-        $filename = $node->filterXPath('//datei')->text();
+        $filenameNode = $node->filterXPath('.//datei');
+        if (0 === $filenameNode->count()) {
+            throw new \InvalidArgumentException('Missing filename node in document response.');
+        }
+
+        $filename = $filenameNode->text();
 
         return [$filename, $pdfData];
     }

src/BusProNet/XmlParser/PersonalDataParser.php

@@ -57,7 +57,7 @@ class PersonalDataParser extends AbstractParser
         $remarksNode = $addressDataNode->filterXPath('//bemerkung');
 
         if (0 < $remarksNode->count()) {
-            $personalData->remarks = $remarksNode->text();
+            $personalData->remarks = $this->getStringOrNullValue($remarksNode);
         }
 
         return $personalData;

src/BusProNet/XmlParser/TravelParser.php

@@ -49,36 +49,40 @@ class TravelParser extends AbstractParser
      */
     public function parse(Crawler $node, ?int $hotelId = null): Travel
     {
+        if (0 === $node->count()) {
+            throw new \InvalidArgumentException('Cannot parse travel from empty XML node.');
+        }
+
         $hotelNode = $this->getHotelNode($node, $hotelId);
 
-        $dateFrom = $this->stringToDate($node->attr('termin'));
+        $dateFrom = $this->stringToDate($this->getRequiredAttrValue($node, 'termin', 'travel termin node'));
-        $dateTo = $this->stringToDate($node->attr('bis'));
+        $dateTo = $this->stringToDate($this->getRequiredAttrValue($node, 'bis', 'travel termin node'));
 
         $travel = new Travel();
-        $travel->id = (int) $node->attr('idbuspro');
+        $travel->id = (int) $this->getRequiredAttrValue($node, 'idbuspro', 'travel termin node');
-        $travel->hotelId = (int) $hotelNode->attr('idbuspro');
+        $travel->hotelId = (int) $this->getRequiredAttrValue($hotelNode, 'idbuspro', 'travel hotel node');
-        $travel->label = $this->getStringOrNullValue($node->filterXPath('//text'));
+        $travel->label = $this->getStringOrNullValue($node->filterXPath('.//text'));
         $travel->dateFrom = $dateFrom;
         $travel->dateTo = $dateTo;
-        $travel->code = $node->attr('code');
+        $travel->code = $this->getAttrOrNullValue($node, 'code');
 
         // Parse product code from parent reise node using DOM
         $domNode = $node->getNode(0);
-        if (null !== $domNode && null !== $domNode->parentNode) {
+        if (null !== $domNode && $domNode->parentNode instanceof \DOMElement) {
             $travel->productCode = $domNode->parentNode->getAttribute('code');
         }
 
-        $travel->type = $node->attr('reiseart');
+        $travel->type = $this->getAttrOrNullValue($node, 'reiseart');
-        $travel->priceFrom = $this->stringToFloat($this->getStringOrNullValue($node->filterXPath('//abpreis')));
+        $travel->priceFrom = $this->stringToFloat($this->getStringOrNullValue($node->filterXPath('.//abpreis')));
-        $travel->selectionGroups = $this->getSelectionGroups($node->filterXPath('//selektiongruppe'));
+        $travel->selectionGroups = $this->getSelectionGroups($node->filterXPath('.//selektiongruppe'));
         // Parse only termin-level additional services; exclude hotel-nested duplicates that can override flags.
         $travel->additionalServices = $this
             ->getAdditionalServices($node->filterXPath('.//lei_sonstiges[not(ancestor::hotel)]/leistung'));
         $travel->transportationServices = $this
-            ->getTransportationServices($node->filterXPath('//lei_befoerderung/leistung'));
+            ->getTransportationServices($node->filterXPath('.//lei_befoerderung/leistung'));
         $travel->rooms = $this->getRooms($hotelNode);
-        $travel->pickups = $this->getPickups($node->filterXPath('//zustiege/zustieg'), $dateFrom, true);
+        $travel->pickups = $this->getPickups($node->filterXPath('.//zustiege/zustieg'), $dateFrom, true);
-        $travel->dropOffs = $this->getPickups($node->filterXPath('//zustiege_rueck/zustieg_rueck'), $dateTo, false);
+        $travel->dropOffs = $this->getPickups($node->filterXPath('.//zustiege_rueck/zustieg_rueck'), $dateTo, false);
 
         // Merge drop-off prices into pickups for split pricing support
         $this->mergeDropOffPricesIntoPickups($travel->pickups, $travel->dropOffs);
@@ -103,19 +107,19 @@ class TravelParser extends AbstractParser
         $selectionGroups = [];
 
         $node->each(function (Crawler $groupNode) use (&$selectionGroups) {
-            $groupId = (int) $groupNode->attr('idbuspro');
+            $groupId = (int) $this->getRequiredAttrValue($groupNode, 'idbuspro', 'selection group node');
             $selectionGroup = new CrmSelectionGroup();
             $selectionGroup->id = $groupId;
-            $selectionGroup->label = $groupNode->attr('bezeichnung');
+            $selectionGroup->label = $this->getAttrOrNullValue($groupNode, 'bezeichnung');
 
             $groupNode
-                ->filterXPath('//selektion')
+                ->filterXPath('.//selektion')
                 ->each(function (Crawler $selectionNode) use (&$selectionGroups, &$selectionGroup, $groupId) {
-                    $selectionId = (int) $selectionNode->attr('idbuspro');
+                    $selectionId = (int) $this->getRequiredAttrValue($selectionNode, 'idbuspro', 'selection node');
                     $selection = new CrmSelection();
                     $selection->id = $selectionId;
-                    $selection->label = $selectionNode->attr('bezeichnung');
+                    $selection->label = $this->getAttrOrNullValue($selectionNode, 'bezeichnung');
-                    $selectionGroups[$groupId]['selections'][$selectionId] = $selectionNode->attr('bezeichnung');
+                    $selectionGroups[$groupId]['selections'][$selectionId] = $this->getAttrOrNullValue($selectionNode, 'bezeichnung');
                     $selectionGroup->selections[] = $selection;
                 })
             ;
@@ -141,26 +145,26 @@ class TravelParser extends AbstractParser
         $additionalServices = [];
 
         $node->each(function (Crawler $serviceNode) use (&$additionalServices) {
-            $serviceId = (int) $serviceNode->attr('idbuspro');
+            $serviceId = (int) $this->getRequiredAttrValue($serviceNode, 'idbuspro', 'additional service node');
 
             $service = new Service();
             $service->source = Constants::SOURCE_TRAVEL;
             $service->category = Constants::CATEGORY_ADDITIONAL;
             $service->id = $serviceId;
-            $service->subType = $serviceNode->attr('unterart');
+            $service->subType = $this->getAttrOrNullValue($serviceNode, 'unterart');
-            $service->mandatory = $this->stringToBool($serviceNode->attr('pflicht'));
+            $service->mandatory = $this->stringToBool($this->getAttrOrNullValue($serviceNode, 'pflicht'));
-            $autoBookValue = $serviceNode->attr('automatisch_buchen');
+            $autoBookValue = $this->getAttrOrNullValue($serviceNode, 'automatisch_buchen');
             $service->autoBook = $this->stringToBool($autoBookValue)
                 || 'true' === strtolower((string) $autoBookValue);
-            $service->dateFrom = $this->stringToDate($serviceNode->attr('termin'));
+            $service->dateFrom = $this->stringToDate($this->getAttrOrNullValue($serviceNode, 'termin'));
-            $service->dateTo = $this->stringToDate($serviceNode->attr('bis'));
+            $service->dateTo = $this->stringToDate($this->getAttrOrNullValue($serviceNode, 'bis'));
-            $service->label = $this->getStringOrNullValue($serviceNode->filterXPath('//text'));
+            $service->label = $this->getStringOrNullValue($serviceNode->filterXPath('.//text'));
             $service->price = $this
-                ->stringToFloat($this->getStringOrNullValue($serviceNode->filterXPath('//preis')));
+                ->stringToFloat($this->getStringOrNullValue($serviceNode->filterXPath('.//preis')));
-            $service->status = $this->getStringOrNullValue($serviceNode->filterXPath('//status'));
+            $service->status = $this->getStringOrNullValue($serviceNode->filterXPath('.//status'));
 
             // Parse optional description from hinweis node
-            $description = $this->getStringOrNullValue($serviceNode->filterXPath('//hinweis'));
+            $description = $this->getStringOrNullValue($serviceNode->filterXPath('.//hinweis'));
             if (null !== $description && '' !== trim($description)) {
                 $service->description = $description;
             }
@@ -169,7 +173,7 @@ class TravelParser extends AbstractParser
             $this->parseServiceAgeConstraints($serviceNode, $service);
 
             // Parse insurance calculation flag
-            $service->includeInInsuranceCalculation = $this->stringToBool($serviceNode->attr('versicherungsberechnung'));
+            $service->includeInInsuranceCalculation = $this->stringToBool($this->getAttrOrNullValue($serviceNode, 'versicherungsberechnung'));
 
             $additionalServices[$serviceId] = $service;
         });
@@ -192,34 +196,34 @@ class TravelParser extends AbstractParser
         $transportationServices = [];
 
         $node->each(function (Crawler $serviceNode) use (&$transportationServices) {
-            $serviceId = (int) $serviceNode->attr('idbuspro');
+            $serviceId = (int) $this->getRequiredAttrValue($serviceNode, 'idbuspro', 'transportation service node');
 
             $service = new Service();
             $service->source = Constants::SOURCE_TRAVEL;
             $service->category = Constants::CATEGORY_TRANSPORTATION;
             $service->id = $serviceId;
-            $service->subType = $serviceNode->attr('unterart');
+            $service->subType = $this->getAttrOrNullValue($serviceNode, 'unterart');
-            $service->dateFrom = $this->stringToDate($serviceNode->attr('termin'));
+            $service->dateFrom = $this->stringToDate($this->getAttrOrNullValue($serviceNode, 'termin'));
-            $service->dateTo = $this->stringToDate($serviceNode->attr('bis'));
+            $service->dateTo = $this->stringToDate($this->getAttrOrNullValue($serviceNode, 'bis'));
-            $service->label = $this->getStringOrNullValue($serviceNode->filterXPath('//text'));
+            $service->label = $this->getStringOrNullValue($serviceNode->filterXPath('.//text'));
-            $service->direction = $this->getStringOrNullValue($serviceNode->filterXPath('//richtung'));
+            $service->direction = $this->getStringOrNullValue($serviceNode->filterXPath('.//richtung'));
-            $service->status = $this->getStringOrNullValue($serviceNode->filterXPath('//status'));
+            $service->status = $this->getStringOrNullValue($serviceNode->filterXPath('.//status'));
             $service->price = $this
-                ->stringToFloat($this->getStringOrNullValue($serviceNode->filterXPath('//preis')));
+                ->stringToFloat($this->getStringOrNullValue($serviceNode->filterXPath('.//preis')));
 
             // Parse optional description from hinweis node
-            $description = $this->getStringOrNullValue($serviceNode->filterXPath('//hinweis'));
+            $description = $this->getStringOrNullValue($serviceNode->filterXPath('.//hinweis'));
             if (null !== $description && '' !== trim($description)) {
                 $service->description = $description;
             }
 
-            if (null !== $timeFrom = $serviceNode->attr('uhrzeit_von')) {
+            if (null !== $timeFrom = $this->getAttrOrNullValue($serviceNode, 'uhrzeit_von')) {
                 $service->timeFrom = $timeFrom;
                 $service->dayTime = (new DayTimeUtility())->mapTime($timeFrom);
             }
 
             // Parse insurance calculation flag
-            $service->includeInInsuranceCalculation = $this->stringToBool($serviceNode->attr('versicherungsberechnung'));
+            $service->includeInInsuranceCalculation = $this->stringToBool($this->getAttrOrNullValue($serviceNode, 'versicherungsberechnung'));
 
             $transportationServices[$serviceId] = $service;
         });
@@ -246,8 +250,8 @@ class TravelParser extends AbstractParser
             $guideNode = $guideNodes->first();
 
             $guide = new Guide();
-            $guide->name = $this->getStringOrNullValue($guideNode->filterXPath('//name'));
+            $guide->name = $this->getStringOrNullValue($guideNode->filterXPath('.//name'));
-            $guide->phone = $this->getStringOrNullValue($guideNode->filterXPath('//telefon'));
+            $guide->phone = $this->getStringOrNullValue($guideNode->filterXPath('.//telefon'));
 
             return $guide;
         }
@@ -321,10 +325,20 @@ class TravelParser extends AbstractParser
     {
         // In case not hotel id is provided, take the first hotel node (which is most probably the only one)
         if (null === $hotelId) {
-            return $node->filterXPath('//hotel')->first();
+            $hotelNode = $node->filterXPath('.//hotel');
+
+            if (0 === $hotelNode->count()) {
+                throw new \InvalidArgumentException('No hotel node found in travel XML.');
             }
 
-        $hotelNode = $node->filterXPath(sprintf('//hotel[@idbuspro="%d"]', $hotelId));
+            return $hotelNode->first();
+        }
+
+        $hotelNode = $node->filterXPath(sprintf('.//hotel[@idbuspro="%d"]', $hotelId));
+
+        if (0 === $hotelNode->count()) {
+            throw new \InvalidArgumentException(sprintf('No hotel node found for idbuspro %d.', $hotelId));
+        }
 
         return $hotelNode->first();
     }
@@ -341,7 +355,7 @@ class TravelParser extends AbstractParser
      */
     public function getRooms(Crawler $node): array
     {
-        $roomNodes = $node->filterXPath('//zimmer/preis');
+        $roomNodes = $node->filterXPath('.//zimmer/preis');
 
         if (0 === $roomNodes->count()) {
             return [];
@@ -350,27 +364,29 @@ class TravelParser extends AbstractParser
         $rooms = [];
 
         $roomNodes->each(function (Crawler $roomNode) use (&$rooms) {
-            $roomCode = $roomNode->attr('zimmercode');
+            $roomCode = $this->getAttrOrNullValue($roomNode, 'zimmercode');
 
             if (true === in_array($roomCode, $this->ignoredRoomCodes, true)) {
                 return;
             }
 
-            $roomId = (int) $roomNode->attr('idbuspro_zimmer');
+            $roomId = (int) $this->getRequiredAttrValue($roomNode, 'idbuspro_zimmer', 'room price node');
 
             $room = new Room();
             $room->id = $roomId;
             $room->code = $roomCode;
-            $room->category = $roomNode->attr('kat');
+            $room->category = $this->getAttrOrNullValue($roomNode, 'kat');
-            $room->boardId = (int) $roomNode->attr('idbuspro_vp');
+            $room->boardId = (int) $this->getAttrOrNullValue($roomNode, 'idbuspro_vp');
-            $room->label = $roomNode->attr('zimmertext');
+            $room->label = $this->getAttrOrNullValue($roomNode, 'zimmertext');
-            $room->minPax = (int) $roomNode->attr('minpax');
+            $room->minPax = (int) $this->getAttrOrNullValue($roomNode, 'minpax');
-            $room->maxPax = (int) $roomNode->attr('maxpax');
+            $room->maxPax = (int) $this->getAttrOrNullValue($roomNode, 'maxpax');
-            $room->nights = (int) $roomNode->attr('naechte');
+            $room->nights = (int) $this->getAttrOrNullValue($roomNode, 'naechte');
-            $room->price = $roomNode->attr('preis') ?
+            $roomPrice = $this->getAttrOrNullValue($roomNode, 'preis');
-                $this->stringToFloat($roomNode->attr('preis')) : null;
+            $room->price = null !== $roomPrice && '' !== $roomPrice
-            $room->status = $roomNode->attr('status');
+                ? $this->stringToFloat($roomPrice)
-            $room->available = (int) $roomNode->attr('verfuegbar');
+                : null;
+            $room->status = $this->getAttrOrNullValue($roomNode, 'status');
+            $room->available = (int) $this->getAttrOrNullValue($roomNode, 'verfuegbar');
 
             $rooms[$roomId] = $room;
         });