feat: add handling for fatal errors by the gateway (#25)

src/Service/CommunicationService.php

@@ -92,10 +92,15 @@ public function send($xml, $connectionTimeout = 0, $executionTimeout = 0, $retri
 
         $errno = curl_errno($ch);
 
+        $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+
         // close connection
         curl_close($ch);
 
-        if ($response === false) {
+        // status codes 3xx and 5xx are not processable by the SDK (we assume that the body will be invalid too)
+        $invalidStatusCode = $statusCode < 200 || ($statusCode >= 300 && ($statusCode < 400 || $statusCode >= 500));
+
+        if ($invalidStatusCode || $response === false) {
             if ($retries > 0) {
                 if ($retryDelay > 0) {
                     // halt time in milliseconds (entered microseconds * 1000)
@@ -108,6 +113,10 @@ public function send($xml, $connectionTimeout = 0, $executionTimeout = 0, $retri
             if ($errno > 0) {
                 throw new CurlException(curl_strerror($errno));
             }
+
+            if ($invalidStatusCode) {
+                throw new CurlException('There server answered with an invalid status code.');
+            }
         }
 
         return $response;

src/Service/ValidateGatewayResponse.php

@@ -13,6 +13,8 @@
 
 namespace RatePAY\Service;
 
+use RatePAY\Exception\RequestException;
+
 /**
  * Class ValidateGatewayResponse.
  */
@@ -44,9 +46,17 @@ public function __construct($requestType, \SimpleXMLElement $response)
         $responsePath = 'RatePAY\\Model\\Response\\';
         $responseInstance = $responsePath . $this->responseType;
 
-        $this->responseModel = new $responseInstance($response);
+        try {
+            $this->responseModel = new $responseInstance($response);
 
-        $this->responseModel->validateResponse();
+            $this->responseModel->validateResponse();
+        } catch (\Throwable $exception) {
+            // this catch works only on PHP < 7.0. On PHP versions lower than 7.0 the error will be propagated because
+            // it is not catchable.
+            // This will catch all errors which will throw by accessing non-existing fields or methods on objects
+            $message = $exception->getPrevious() ? $exception->getPrevious()->getMessage() : $exception->getMessage();
+            throw new RequestException(sprintf('An error occurred during the processing of the response from the gateway. Error message: %s', $message));
+        }
     }
 
     /**

tests/Unit/Service/CommunicationServiceTest.php

@@ -74,6 +74,19 @@ function curl_strerror($errorCode)
 
         return $messages[$errorCode];
     }
+
+    function curl_getinfo($handle, $optionCode)
+    {
+        if (!should_call_mocked_global_functions()) {
+            return call_user_func_array('\curl_getinfo', func_get_args());
+        }
+
+        if ($optionCode === CURLINFO_HTTP_CODE) {
+            return CommunicationServiceTest::$forceHttpStatus;
+        }
+
+        return null;
+    }
 }
 
 namespace RatePAY\Tests\Unit\Service {
@@ -89,6 +102,7 @@ class CommunicationServiceTest extends TestCase
         public static $curlDataMock = [];
         public static $curlExecutions = 0;
         public static $expectedCurlFailures = 0;
+        public static $forceHttpStatus = 200;
 
         /**
          * This method is called before the first test of this test class is run.
@@ -168,6 +182,18 @@ public function testSendAndRetryCurl()
             $this->assertEquals('cURL Executed!', $response);
         }
 
+        public function testCurlRequestWillFailWithHttpError500()
+        {
+            self::$forceHttpStatus = 500;
+            $xml = '<?xml version="1.0" encoding="UTF-8"?><note><to>Foo</to></note>';
+
+            $this->expectException(CurlException::class);
+            $this->expectExceptionMessage('There server answered with an invalid status code.');
+
+            $service = new CommunicationService();
+            $service->send($xml, 0, 0, 6, 1);
+        }
+
         public static function incrementCurlExcecutions()
         {
             self::$curlExecutions++;

tests/Unit/Service/ValidateGatewayResponseTest.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * Ratepay PHP-Library
+ *
+ * This document contains trade secret data which are the property of
+ * Ratepay GmbH, Berlin, Germany. Information contained herein must not be used,
+ * copied or disclosed in whole or part unless permitted in writing by Ratepay GmbH.
+ * All rights reserved by Ratepay GmbH.
+ *
+ * Copyright (c) 2022 Ratepay GmbH / Berlin / Germany
+ */
+
+namespace RatePAY\Service;
+
+use PHPUnit\Framework\TestCase;
+use RatePAY\Exception\RequestException;
+
+class ValidateGatewayResponseTest extends TestCase
+{
+
+    /**
+     * @requires PHPUnit 7.5
+     */
+    public function testIfExceptionWillThrownIfUnexpectedXML()
+    {
+        $xml = '<?xml version="1.0" encoding="UTF-8"?><note><to>Foo</to></note>';
+
+        $this->expectException(RequestException::class);
+        $this->expectExceptionMessageMatches('/An error occurred during the processing of the response from the gateway. Error message: (.*)/');
+
+        new ValidateGatewayResponse('PaymentInit', new \SimpleXMLElement($xml));
+    }
+}