[ErrorHandler] Rewrite logic to dump exception properties and fix serializing FlattenException

Author: nicolas-grekas

ErrorRenderer/HtmlErrorRenderer.php

@@ -17,7 +17,7 @@
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Debug\FileLinkFormatter;
 use Symfony\Component\HttpKernel\Log\DebugLoggerInterface;
-use Symfony\Component\VarDumper\Cloner\VarCloner;
+use Symfony\Component\VarDumper\Cloner\Data;
 use Symfony\Component\VarDumper\Dumper\HtmlDumper;
 
 /**
@@ -69,7 +69,7 @@ public function render(\Throwable $exception): FlattenException
             $headers['X-Debug-Exception-File'] = rawurlencode($exception->getFile()).':'.$exception->getLine();
         }
 
-        $exception = FlattenException::createFromThrowable($exception, null, $headers);
+        $exception = FlattenException::createWithDataRepresentation($exception, null, $headers);
 
         return $exception->setAsString($this->renderException($exception));
     }
@@ -149,21 +149,12 @@ private function renderException(FlattenException $exception, string $debugTempl
         ]);
     }
 
-    private function dumpValue(mixed $value): string
+    private function dumpValue(Data $value): string
     {
-        $cloner = new VarCloner();
-        $data = $cloner->cloneVar($value);
-
         $dumper = new HtmlDumper();
         $dumper->setTheme('light');
-        $dumper->setOutput($output = fopen('php://memory', 'r+'));
-        $dumper->dump($data);
-
-        $dump = stream_get_contents($output, -1, 0);
-        rewind($output);
-        ftruncate($output, 0);
 
-        return $dump;
+        return $dumper->dump($value, true);
     }
 
     private function formatArgs(array $args): string

Exception/FlattenException.php

@@ -14,6 +14,10 @@
 use Symfony\Component\HttpFoundation\Exception\RequestExceptionInterface;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
+use Symfony\Component\VarDumper\Caster\Caster;
+use Symfony\Component\VarDumper\Cloner\Data;
+use Symfony\Component\VarDumper\Cloner\Stub;
+use Symfony\Component\VarDumper\Cloner\VarCloner;
 
 /**
  * FlattenException wraps a PHP Error or Exception to be able to serialize it.
@@ -36,7 +40,7 @@ class FlattenException
     private string $file;
     private int $line;
     private ?string $asString = null;
-    private array $properties = [];
+    private Data $dataRepresentation;
 
     public static function create(\Exception $exception, int $statusCode = null, array $headers = []): static
     {
@@ -78,14 +82,34 @@ public static function createFromThrowable(\Throwable $exception, int $statusCod
             $e->setPrevious(static::createFromThrowable($previous));
         }
 
-        if ((new \ReflectionClass($exception::class))->isUserDefined()) {
-            $getProperties = \Closure::bind(fn (\Throwable $e) => get_object_vars($e), null, $exception::class);
-            $properties = $getProperties($exception);
-            unset($properties['message'], $properties['code'], $properties['file'], $properties['line']);
-            $e->properties = $properties;
+        return $e;
+    }
+
+    public static function createWithDataRepresentation(\Throwable $throwable, int $statusCode = null, array $headers = [], VarCloner $cloner = null): static
+    {
+        $e = static::createFromThrowable($throwable, $statusCode, $headers);
+
+        static $defaultCloner;
+
+        if (!$cloner ??= $defaultCloner) {
+            $cloner = $defaultCloner = new VarCloner();
+            $cloner->addCasters([
+                \Throwable::class => function (\Throwable $e, array $a, Stub $s, bool $isNested): array {
+                    if (!$isNested) {
+                        unset($a[Caster::PREFIX_PROTECTED.'message']);
+                        unset($a[Caster::PREFIX_PROTECTED.'code']);
+                        unset($a[Caster::PREFIX_PROTECTED.'file']);
+                        unset($a[Caster::PREFIX_PROTECTED.'line']);
+                        unset($a["\0Error\0trace"], $a["\0Exception\0trace"]);
+                        unset($a["\0Error\0previous"], $a["\0Exception\0previous"]);
+                    }
+
+                    return $a;
+                },
+            ]);
         }
 
-        return $e;
+        return $e->setDataRepresentation($cloner->cloneVar($throwable));
     }
 
     public function toArray(): array
@@ -96,7 +120,7 @@ public function toArray(): array
                 'message' => $exception->getMessage(),
                 'class' => $exception->getClass(),
                 'trace' => $exception->getTrace(),
-                'properties' => $exception->getProperties(),
+                'data' => $exception->getDataRepresentation(),
             ];
         }
 
@@ -230,11 +254,6 @@ public function setCode(int|string $code): static
         return $this;
     }
 
-    public function getProperties(): array
-    {
-        return $this->properties;
-    }
-
     public function getPrevious(): ?self
     {
         return $this->previous;
@@ -319,6 +338,21 @@ public function setTrace(array $trace, ?string $file, ?int $line): static
         return $this;
     }
 
+    public function getDataRepresentation(): ?Data
+    {
+        return $this->dataRepresentation ?? null;
+    }
+
+    /**
+     * @return $this
+     */
+    public function setDataRepresentation(Data $data): static
+    {
+        $this->dataRepresentation = $data;
+
+        return $this;
+    }
+
     private function flattenArgs(array $args, int $level = 0, int &$count = 0): array
     {
         $result = [];

Resources/views/traces.html.php

@@ -25,11 +25,11 @@
                     <p class="break-long-words trace-message"><?= $this->escape($exception['message']); ?></p>
                 <?php } ?>
             </div>
-            <?php if ($exception['properties']) { ?>
+            <?php if (\count($exception['data'] ?? [])) { ?>
                 <details class="exception-properties-wrapper">
                     <summary>Show exception properties</summary>
                     <div class="exception-properties">
-                        <?= $this->dumpValue($exception['properties']) ?>
+                        <?= $this->dumpValue($exception['data']) ?>
                     </div>
                 </details>
             <?php } ?>

Tests/Exception/FlattenExceptionTest.php

@@ -209,7 +209,7 @@ public function testToArray(\Throwable $exception, string $expectedClass)
                     'namespace' => '', 'short_class' => '', 'class' => '', 'type' => '', 'function' => '', 'file' => 'foo.php', 'line' => 123,
                     'args' => [],
                 ]],
-                'properties' => [],
+                'data' => null,
             ],
         ], $flattened->toArray());
     }