Fix batch response decoding when regex finds no JSON match

src/ODataResponse.php

@@ -90,8 +90,9 @@ private function decodeBody()
         $decodedBody = json_decode($this->body, true, 512, JSON_BIGINT_AS_STRING);
         if ($decodedBody === null) {
             $matches = null;
-            preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches);
-            $decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
+            if (preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches)) {
+                $decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
+            }
             if ($decodedBody === null) {
                 $decodedBody = array();
             }

tests/BatchResponseTest.php

@@ -0,0 +1,158 @@
+<?php
+
+namespace SaintSystems\OData\Tests;
+
+// If running standalone, load autoloader
+if (basename(__FILE__) === basename($_SERVER['PHP_SELF'])) {
+    require_once __DIR__ . '/../vendor/autoload.php';
+}
+
+use SaintSystems\OData\ODataResponse;
+use SaintSystems\OData\ODataRequest;
+
+// Check if PHPUnit is available, if not provide a fallback
+if (class_exists('PHPUnit\Framework\TestCase')) {
+    class BatchResponseTestBase extends \PHPUnit\Framework\TestCase {}
+} else {
+    // Fallback base class for when PHPUnit is not available
+    class BatchResponseTestBase {
+        protected function createMock($className) {
+            return new \stdClass();
+        }
+        protected function assertIsArray($value) { 
+            if (!is_array($value)) throw new \Exception("Expected array"); 
+        }
+        protected function assertEquals($expected, $actual, $message = '') { 
+            if ($expected !== $actual) throw new \Exception($message ?: "Assertion failed: $expected !== $actual"); 
+        }
+        protected function assertTrue($value, $message = '') { 
+            if (!$value) throw new \Exception($message ?: "Assertion failed: Expected true"); 
+        }
+    }
+}
+
+class BatchResponseTest extends BatchResponseTestBase
+{
+    /**
+     * Test that batch responses with multipart MIME content don't crash
+     * This reproduces the issue reported in GitHub where SAP SuccessFactors
+     * batch responses cause "Undefined array key 0" error
+     */
+    public function testBatchResponseWithMultipartContent()
+    {
+        // Simulate a batch response from SAP SuccessFactors
+        $batchResponseBody = <<<EOT
+--batch_f20d8021-677a-4f93-8e62-862b6f383d15
+Content-Type: application/http
+Content-Transfer-Encoding: binary
+
+HTTP/1.1 200 OK
+Content-Type: application/json;charset=utf-8
+DataServiceVersion: 2.0
+Record-Count: 5
+X-SF-Record-Count-Recursive: 5
+successfactors-message: X-SF-Correlation-Id, successfactors-sourcetype are missing in request headers
+Content-Length: 76038
+
+{
+"d" : {
+"results" : [
+  {"id": 1, "name": "Test 1"},
+  {"id": 2, "name": "Test 2"}
+]
+}
+}
+
+--batch_f20d8021-677a-4f93-8e62-862b6f383d15--
+EOT;
+
+        $request = $this->createMock(ODataRequest::class);
+
+        // This should not throw an exception
+        $response = new ODataResponse($request, $batchResponseBody, 200, []);
+
+        // The response should be created successfully
+        $this->assertTrue(true, "ODataResponse should handle batch responses without crashing");
+
+        // The body should be decoded to at least an empty array (no crash)
+        $body = $response->getBody();
+        $this->assertIsArray($body);
+    }
+
+    /**
+     * Test that responses with no JSON content don't crash
+     */
+    public function testResponseWithNoJsonContent()
+    {
+        $nonJsonResponse = "This is plain text with no JSON at all";
+
+        $request = $this->createMock(ODataRequest::class);
+
+        // This should not throw an exception
+        $response = new ODataResponse($request, $nonJsonResponse, 200, []);
+
+        // The body should be decoded to an empty array
+        $body = $response->getBody();
+        $this->assertIsArray($body);
+        $this->assertEquals([], $body);
+    }
+
+    /**
+     * Test that responses with embedded JSON still work
+     */
+    public function testResponseWithEmbeddedJson()
+    {
+        $responseWithEmbeddedJson = 'Some text before {"value": "test"} some text after';
+
+        $request = $this->createMock(ODataRequest::class);
+
+        // This should not throw an exception
+        $response = new ODataResponse($request, $responseWithEmbeddedJson, 200, []);
+
+        // The body should extract the JSON portion
+        $body = $response->getBody();
+        $this->assertIsArray($body);
+        $this->assertEquals('test', $body['value']);
+    }
+
+    /**
+     * Test normal JSON response still works correctly
+     */
+    public function testNormalJsonResponse()
+    {
+        $jsonResponse = json_encode(['value' => 'test', 'count' => 5]);
+
+        $request = $this->createMock(ODataRequest::class);
+        $response = new ODataResponse($request, $jsonResponse, 200, []);
+
+        $body = $response->getBody();
+        $this->assertIsArray($body);
+        $this->assertEquals('test', $body['value']);
+        $this->assertEquals(5, $body['count']);
+    }
+}
+
+// If running standalone (not via PHPUnit), execute the tests
+if (!class_exists('PHPUnit\Framework\TestCase') && basename(__FILE__) === basename($_SERVER['PHP_SELF'])) {
+    echo "Running BatchResponse tests...\n\n";
+
+    $test = new BatchResponseTest();
+    $methods = [
+        'testBatchResponseWithMultipartContent',
+        'testResponseWithNoJsonContent',
+        'testResponseWithEmbeddedJson',
+        'testNormalJsonResponse'
+    ];
+
+    foreach ($methods as $method) {
+        try {
+            echo "Running $method... ";
+            $test->$method();
+            echo "✓ PASSED\n";
+        } catch (\Exception $e) {
+            echo "✗ FAILED: " . $e->getMessage() . "\n";
+        }
+    }
+
+    echo "\nTests completed.\n";
+}