[PAR-735] Fix memory exhaustion in LoggerService when logging complex objects (#16)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: mescalantea

src/Service/Infrastructure/LoggerService.php

@@ -45,7 +45,7 @@ public function logMessage(LogData $data): void
         if (!empty($context)) {
             $contextData = array();
             foreach ($context as $item) {
-                $contextData[$item->getName()] = print_r($item->getValue(), true);
+                $contextData[$item->getName()] = $this->formatContextValue($item->getValue());
             }
 
             $logMessage .= PHP_EOL . 'Context data: ' . print_r($contextData, true);
@@ -65,4 +65,27 @@ public function logMessage(LogData $data): void
                 Log::info($logMessage);
         }
     }
+
+    /**
+     * Formats a context value for safe logging without unbounded memory allocation.
+     *
+     * @param mixed $value
+     *
+     * @return string
+     */
+    private function formatContextValue(mixed $value): string
+    {
+        if ($value instanceof \Throwable) {
+            return get_class($value) . ': ' . $value->getMessage()
+                . ' in ' . $value->getFile() . ':' . $value->getLine();
+        }
+
+        if (is_object($value)) {
+            $encoded = json_encode($value, JSON_PARTIAL_OUTPUT_ON_ERROR, 5);
+
+            return $encoded !== false ? $encoded : get_class($value) . ' (not serializable)';
+        }
+
+        return print_r($value, true);
+    }
 }

tests/Unit/LoggerServiceTest.php

@@ -0,0 +1,109 @@
+<?php
+
+namespace SeQura\Middleware\Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+use SeQura\Middleware\Service\Infrastructure\LoggerService;
+
+/**
+ * Class LoggerServiceTest
+ *
+ * @package SeQura\Middleware\Tests\Unit
+ */
+class LoggerServiceTest extends TestCase
+{
+    private \ReflectionMethod $formatContextValue;
+    private LoggerService $loggerService;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->loggerService = LoggerService::getInstance();
+
+        $this->formatContextValue = new \ReflectionMethod(LoggerService::class, 'formatContextValue');
+        $this->formatContextValue->setAccessible(true);
+    }
+
+    public function testThrowableIsFormattedWithoutPrintR(): void
+    {
+        $exception = new \RuntimeException('Something went wrong');
+
+        $result = $this->formatContextValue->invoke($this->loggerService, $exception);
+
+        $this->assertStringContainsString('RuntimeException: Something went wrong', $result);
+        $this->assertStringContainsString(__FILE__, $result);
+        // Must NOT contain full stack trace output from print_r
+        $this->assertStringNotContainsString('#0 ', $result);
+        $this->assertStringNotContainsString('Array', $result);
+    }
+
+    public function testNestedExceptionOnlyShowsOuterException(): void
+    {
+        $previous = new \InvalidArgumentException('Root cause');
+        $exception = new \RuntimeException('Wrapper', 0, $previous);
+
+        $result = $this->formatContextValue->invoke($this->loggerService, $exception);
+
+        $this->assertStringContainsString('RuntimeException: Wrapper', $result);
+        // Should NOT recurse into the previous exception
+        $this->assertStringNotContainsString('Root cause', $result);
+        $this->assertStringNotContainsString('#0 ', $result);
+    }
+
+    public function testObjectUsesJsonEncode(): void
+    {
+        $object = new \stdClass();
+        $object->key = 'value';
+        $object->number = 42;
+
+        $result = $this->formatContextValue->invoke($this->loggerService, $object);
+
+        $this->assertStringContainsString('"key":"value"', $result);
+        $this->assertStringContainsString('"number":42', $result);
+    }
+
+    public function testNonSerializableObjectFallsBackToClassName(): void
+    {
+        $object = new class {
+            public float $value = NAN;
+        };
+
+        $result = $this->formatContextValue->invoke($this->loggerService, $object);
+
+        // JSON_PARTIAL_OUTPUT_ON_ERROR will produce output or fall back to class name
+        $this->assertNotEmpty($result);
+        // Should not crash or produce unbounded output
+        $this->assertLessThan(1000, strlen($result));
+    }
+
+    public function testScalarStringIsReturnedAsIs(): void
+    {
+        $result = $this->formatContextValue->invoke($this->loggerService, 'simple string');
+
+        $this->assertEquals('simple string', $result);
+    }
+
+    public function testIntegerIsReturnedViaPrintR(): void
+    {
+        $result = $this->formatContextValue->invoke($this->loggerService, 42);
+
+        $this->assertEquals('42', $result);
+    }
+
+    public function testArrayIsReturnedViaPrintR(): void
+    {
+        $result = $this->formatContextValue->invoke($this->loggerService, ['a', 'b', 'c']);
+
+        $this->assertStringContainsString('a', $result);
+        $this->assertStringContainsString('b', $result);
+        $this->assertStringContainsString('c', $result);
+    }
+
+    public function testNullIsHandled(): void
+    {
+        $result = $this->formatContextValue->invoke($this->loggerService, null);
+
+        $this->assertIsString($result);
+    }
+}