test: Add verification for exception property handling in ErrorHandler class.

src/http/StatelessApplication.php

@@ -7,7 +7,6 @@
 use Psr\Http\Message\{ResponseInterface, ServerRequestInterface};
 use Psr\Http\Server\RequestHandlerInterface;
 use Throwable;
-use Yii;
 use yii\base\{Event, InvalidConfigException};
 use yii\di\{Container, NotInstantiableException};
 use yii\web\{Application, UploadedFile};
@@ -49,6 +48,21 @@
  */
 final class StatelessApplication extends Application implements RequestHandlerInterface
 {
+    /**
+     * Whether to flush the logger during application termination.
+     *
+     * When enabled (default), the logger will be flushed during the {@see terminate()} method, ensuring that all log
+     * messages are persisted immediately after request processing.
+     *
+     * This is the recommended behavior for production environments and worker-based applications.
+     *
+     * When disabled, log messages will remain in memory and may accumulate across multiple requests.
+     *
+     * **Warning**: Disabling logger flushing in production or worker environments may lead to memory leaks and log
+     * message loss in case of application crashes. Use with caution and ensure proper memory management.
+     */
+    public bool $flushLogger = true;
+
     /**
      * Version of the StatelessApplication.
      */
@@ -446,7 +460,9 @@ protected function terminate(Response $response): ResponseInterface
 
         UploadedFile::reset();
 
-        Yii::getLogger()->flush(true);
+        if ($this->flushLogger) {
+            $this->getLog()->getLogger()->flush(true);
+        }
 
         return $response->getPsr7Response();
     }

tests/http/ErrorHandlerTest.php

@@ -153,6 +153,36 @@ public function testHandleExceptionResetsState(): void
         );
     }
 
+    public function testHandleExceptionSetsExceptionPropertyAndResetsIt(): void
+    {
+        $errorHandler = new ErrorHandler();
+
+        $errorHandler->discardExistingOutput = false;
+
+        $initialException = self::inaccessibleProperty($errorHandler, 'exception');
+
+        self::assertNull(
+            $initialException,
+            "Exception property should be 'null' initially.",
+        );
+
+        $exception = new Exception('Test exception for property verification');
+
+        $response = $errorHandler->handleException($exception);
+
+        $finalException = self::inaccessibleProperty($errorHandler, 'exception');
+
+        self::assertNull(
+            $finalException,
+            "Exception property should be reset to 'null' after handling exception.",
+        );
+        self::assertSame(
+            500,
+            $response->getStatusCode(),
+            'Should set correct status code and reset exception property.',
+        );
+    }
+
     public function testHandleExceptionWithComplexMessage(): void
     {
         $errorHandler = new ErrorHandler();

tests/http/StatelessApplicationTest.php

@@ -13,7 +13,7 @@
 use yii\di\NotInstantiableException;
 use yii\helpers\Json;
 use yii\i18n\{Formatter, I18N};
-use yii\log\Dispatcher;
+use yii\log\{Dispatcher, FileTarget};
 use yii\web\{AssetManager, NotFoundHttpException, Session, UrlManager, User, View};
 use yii2\extensions\psrbridge\exception\Message;
 use yii2\extensions\psrbridge\http\{ErrorHandler, Request, Response};
@@ -580,6 +580,81 @@ public function testGetMemoryLimitHandlesUnlimitedMemoryCorrectly(): void
         ini_set('memory_limit', $originalLimit);
     }
 
+    /**
+     * @throws InvalidConfigException if the configuration is invalid or incomplete.
+     */
+    public function testLogExceptionIsCalledWhenHandlingException(): void
+    {
+        $_SERVER = [
+            'REQUEST_METHOD' => 'GET',
+            'REQUEST_URI' => 'site/trigger-exception',
+        ];
+
+        $request = FactoryHelper::createServerRequestCreator()->createFromGlobals();
+
+        $app = $this->statelessApplication(
+            [
+                'flushLogger' => false,
+                'components' => [
+                    'errorHandler' => [
+                        'errorAction' => null,
+                    ],
+                    'log' => [
+                        'traceLevel' => YII_DEBUG ? 1 : 0,
+                        'targets' => [
+                            [
+                                'class' => FileTarget::class,
+                                'levels' => [
+                                    'error',
+                                ],
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+        );
+
+        $response = $app->handle($request);
+
+        $logMessages = $app->getLog()->getLogger()->messages;
+
+        self::assertSame(
+            500,
+            $response->getStatusCode(),
+            "Response 'status code' should be '500' when an exception occurs in 'StatelessApplication'.",
+        );
+        self::assertNotEmpty(
+            $logMessages,
+            "Logger should contain log messages after handling an exception in 'StatelessApplication'.",
+        );
+
+        $exceptionLogFound = false;
+        $expectedCategory = Exception::class;
+
+        foreach ($logMessages as $logMessage) {
+            if (
+                is_array($logMessage) &&
+                isset($logMessage[0], $logMessage[2]) &&
+                $logMessage[0] instanceof Exception &&
+                $logMessage[2] === $expectedCategory &&
+                str_contains($logMessage[0]->getMessage(), 'Exception error message.')
+            ) {
+                $exceptionLogFound = true;
+                break;
+            }
+        }
+
+        self::assertTrue(
+            $exceptionLogFound,
+            "Logger should contain an error log entry with category '{$expectedCategory}' and message 'Exception error message.' " .
+            "when 'logException()' is called during exception handling in 'StatelessApplication'.",
+        );
+        self::assertFalse(
+            $app->flushLogger,
+            "Test must keep logger messages in memory to assert on them; 'flushLogger' should be 'false'.",
+        );
+    }
+
     /**
      * @throws InvalidConfigException if the configuration is invalid or incomplete.
      */