test(http): Enhance ErrorHandlerTest class with output buffer handling and mocking support.

src/http/ErrorHandler.php

@@ -85,10 +85,8 @@
         $minLevel = YII_ENV_TEST ? 1 : 0;
 
         while ($currentLevel > $minLevel) {
             if (@ob_end_clean() === false) {
-                // @codeCoverageIgnoreStart
                 ob_clean();
-                // @codeCoverageIgnoreEnd
             }
 
             $currentLevel = ob_get_level();

tests/http/ErrorHandlerTest.php

@@ -25,7 +25,7 @@ public function testClearOutputCleansAllBuffersInNonTestEnvironment(): void
         $initialLevel = ob_get_level();
 
         try {
-            @runkit_constant_redefine('YII_ENV_TEST', false);
+            @\runkit_constant_redefine('YII_ENV_TEST', false);
 
             $errorHandler = new ErrorHandler();
 
@@ -56,7 +56,7 @@ public function testClearOutputCleansAllBuffersInNonTestEnvironment(): void
                 ob_start();
             }
 
-            @runkit_constant_redefine('YII_ENV_TEST', true);
+            @\runkit_constant_redefine('YII_ENV_TEST', true);
         }
     }
 

tests/http/stateless/ApplicationErrorHandlerTest.php

@@ -13,9 +13,12 @@
 use yii2\extensions\psrbridge\http\Response;
 use yii2\extensions\psrbridge\tests\provider\StatelessApplicationProvider;
 use yii2\extensions\psrbridge\tests\support\FactoryHelper;
+use yii2\extensions\psrbridge\tests\support\stub\MockerFunctions;
 use yii2\extensions\psrbridge\tests\TestCase;
 
 use function array_filter;
+use function ini_get;
+use function ini_set;
 use function is_array;
 use function ob_get_level;
 use function ob_start;
@@ -346,6 +349,82 @@ static function ($errno, $errstr, $errfile, $errline) use (&$warningsCaptured):
         }
     }
 
+    /**
+     * @throws InvalidConfigException if the configuration is invalid or incomplete.
+     */
+    #[RequiresPhpExtension('runkit7')]
+    public function testRenderExceptionSetsDisplayErrorsInDebugMode(): void
+    {
+        @\runkit_constant_redefine('YII_ENV_TEST', false);
+
+        MockerFunctions::setObEndCleanShouldFail(true);
+
+        $bufferBeforeLevel = ob_get_level();
+
+        $_SERVER = [
+            'REQUEST_METHOD' => 'GET',
+            'REQUEST_URI' => 'site/trigger-exception',
+        ];
+
+        ob_start();
+        echo 'buffer content that should be cleared';
+        ob_start();
+        echo 'nested buffer content';
+
+        $originalDisplayErrors = ini_get('display_errors');
+
+        $app = $this->statelessApplication(
+            [
+                'components' => [
+                    'errorHandler' => [
+                        'discardExistingOutput' => true,
+                        'errorAction' => null,
+                    ],
+                ],
+            ],
+        );
+
+        $response = $app->handle(FactoryHelper::createServerRequestCreator()->createFromGlobals());
+
+        self::assertSame(
+            500,
+            $response->getStatusCode(),
+            "Expected HTTP '500' for route 'site/trigger-exception'.",
+        );
+        self::assertSame(
+            'text/html; charset=UTF-8',
+            $response->getHeaderLine('Content-Type'),
+            "Expected Content-Type 'text/html; charset=UTF-8' for route 'site/trigger-exception'.",
+        );
+        self::assertSame(
+            '1',
+            ini_get('display_errors'),
+            "'display_errors' should be set to '1' in debug mode when rendering exception.",
+        );
+
+        $bufferAfterLevel = ob_get_level();
+
+        self::assertSame(
+            0,
+            $bufferAfterLevel,
+            "Output buffers should be cleared to level '0' when 'discardExistingOutput' is 'true'.",
+        );
+
+        while (ob_get_level() < $bufferBeforeLevel) {
+            ob_start();
+        }
+
+        self::assertSame(
+            $bufferBeforeLevel,
+            ob_get_level(),
+            'Output buffers should be restored to initial level.',
+        );
+
+        ini_set('display_errors', $originalDisplayErrors);
+
+        @\runkit_constant_redefine('YII_ENV_TEST', true);
+    }
+
     /**
      * @throws InvalidConfigException if the configuration is invalid or incomplete.
      *

tests/http/stateless/ApplicationTest.php

@@ -4,16 +4,11 @@
 
 namespace yii2\extensions\psrbridge\tests\http\stateless;
 
-use PHPUnit\Framework\Attributes\{Group, RequiresPhpExtension};
+use PHPUnit\Framework\Attributes\Group;
 use yii\base\InvalidConfigException;
 use yii2\extensions\psrbridge\tests\support\FactoryHelper;
 use yii2\extensions\psrbridge\tests\TestCase;
 
-use function ini_get;
-use function ini_set;
-use function ob_get_level;
-use function ob_start;
-
 #[Group('http')]
 final class ApplicationTest extends TestCase
 {
@@ -24,65 +19,6 @@ protected function tearDown(): void
         parent::tearDown();
     }
 
-    /**
-     * @throws InvalidConfigException if the configuration is invalid or incomplete.
-     */
-    #[RequiresPhpExtension('runkit7')]
-    public function testRenderExceptionSetsDisplayErrorsInDebugMode(): void
-    {
-        @\runkit_constant_redefine('YII_ENV_TEST', false);
-
-        $initialBufferLevel = ob_get_level();
-
-        $_SERVER = [
-            'REQUEST_METHOD' => 'GET',
-            'REQUEST_URI' => 'site/trigger-exception',
-        ];
-
-        $originalDisplayErrors = ini_get('display_errors');
-
-        try {
-            $app = $this->statelessApplication(
-                [
-                    'components' => [
-                        'errorHandler' => ['errorAction' => null],
-                    ],
-                ],
-            );
-
-            $response = $app->handle(FactoryHelper::createServerRequestCreator()->createFromGlobals());
-
-            self::assertSame(
-                500,
-                $response->getStatusCode(),
-                "Expected HTTP '500' for route 'site/trigger-exception'.",
-            );
-            self::assertSame(
-                'text/html; charset=UTF-8',
-                $response->getHeaderLine('Content-Type'),
-                "Expected Content-Type 'text/html; charset=UTF-8' for route 'site/trigger-exception'.",
-            );
-            self::assertSame(
-                '1',
-                ini_get('display_errors'),
-                "'display_errors' should be set to '1' when YII_DEBUG mode is enabled and rendering exception view.",
-            );
-            self::assertStringContainsString(
-                'yii\base\Exception: Exception error message.',
-                $response->getBody()->getContents(),
-                'Response should contain exception details when YII_DEBUG mode is enabled.',
-            );
-        } finally {
-            ini_set('display_errors', $originalDisplayErrors);
-
-            while (ob_get_level() < $initialBufferLevel) {
-                ob_start();
-            }
-
-            @\runkit_constant_redefine('YII_ENV_TEST', true);
-        }
-    }
-
     /**
      * @throws InvalidConfigException if the configuration is invalid or incomplete.
      */

tests/support/MockerExtension.php

@@ -85,6 +85,11 @@ public static function load(): void
                 'name' => 'microtime',
                 'function' => static fn(bool $as_float = false): float|string => MockerFunctions::microtime($as_float),
             ],
+            [
+                'namespace' => 'yii2\extensions\psrbridge\http',
+                'name' => 'ob_end_clean',
+                'function' => static fn(): bool => MockerFunctions::ob_end_clean(),
+            ],
             [
                 'namespace' => 'yii2\extensions\psrbridge\adapter',
                 'name' => 'stream_get_contents',

tests/support/stub/MockerFunctions.php

@@ -33,6 +33,7 @@
  *   - {@see \headers_sent()} (with file/line tracking).
  *   - {@see \http_response_code()} (get/set response code).
  *   - {@see \microtime()} (mockable time for timing tests).
+ *   - {@see \ob_end_clean()} (controllable success/failure).
  *   - {@see \stream_get_contents()} (controllable stream read/failure).
  *   - {@see \time()} (mockable time for timing tests).
  * - Consistent behavior matching PHP native functions for test reliability.
@@ -84,6 +85,16 @@ final class MockerFunctions
      */
     private static int|null $mockedTime = null;
 
+    /**
+     * Tracks the number of times {@see \ob_end_clean()} was called.
+     */
+    private static int $obEndCleanCallCount = 0;
+
+    /**
+     * Indicates whether {@see \ob_end_clean()} should fail.
+     */
+    private static bool $obEndCleanShouldFail = false;
+
     /**
      * Tracks the HTTP response code.
      */
@@ -190,6 +201,18 @@ public static function microtime(bool $as_float = false): float|string
         return \microtime($as_float);
     }
 
+    public static function ob_end_clean(): bool
+    {
+        self::$obEndCleanCallCount++;
+
+        // simulate failure only on the first call after enabling
+        if (self::$obEndCleanShouldFail && self::$obEndCleanCallCount === 1) {
+            return false;
+        }
+
+        return @\ob_end_clean();
+    }
+
     public static function reset(): void
     {
         self::$flushedTimes = 0;
@@ -198,8 +221,11 @@ public static function reset(): void
         self::$headersSentFile = '';
         self::$headersSentLine = 0;
         self::$mockedTime = null;
+        self::$obEndCleanCallCount = 0;
+        self::$obEndCleanShouldFail = false;
         self::$responseCode = 200;
         self::$streamGetContentsShouldFail = false;
+
         self::clearMockedMicrotime();
     }
 
@@ -225,6 +251,15 @@ public static function setMockedTime(int $time): void
         self::$mockedTime = $time;
     }
 
+    public static function setObEndCleanShouldFail(bool $shouldFail = true): void
+    {
+        self::$obEndCleanShouldFail = $shouldFail;
+
+        if ($shouldFail) {
+            self::$obEndCleanCallCount = 0;
+        }
+    }
+
     public static function stream_get_contents(mixed $resource, int $maxlength = -1, int $offset = -1): string|false
     {
         if (self::$streamGetContentsShouldFail) {