minor #813 Catch serializer exception (VincentLanglet)

This PR was squashed before being merged into the main branch.

Discussion
----------

 Catch serializer exception

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Docs?         | no <!-- required for new features -->
| Issues        | Fix #786
| License       | MIT

I don't really have inspiration for error message, I'm pretty sure you'll have good suggestion `@OskarStark`

Commits
-------

e39437a  Catch serializer exception

Author: chr-hertel

src/agent/src/Toolbox/ToolResultConverter.php

@@ -11,7 +11,9 @@
 
 namespace Symfony\AI\Agent\Toolbox;
 
+use Symfony\AI\Agent\Exception\RuntimeException;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
+use Symfony\Component\Serializer\Exception\ExceptionInterface as SerializerExceptionInterface;
 use Symfony\Component\Serializer\Normalizer\DateTimeNormalizer;
 use Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
@@ -28,6 +30,9 @@ public function __construct(
     ) {
     }
 
+    /**
+     * @throws RuntimeException
+     */
     public function convert(ToolResult $toolResult): ?string
     {
         $result = $toolResult->getResult();
@@ -40,6 +45,10 @@ public function convert(ToolResult $toolResult): ?string
             return (string) $result;
         }
 
-        return $this->serializer->serialize($result, 'json');
+        try {
+            return $this->serializer->serialize($result, 'json');
+        } catch (SerializerExceptionInterface $e) {
+            throw new RuntimeException('Cannot serialize the tool result.', previous: $e);
+        }
     }
 }

src/platform/src/StructuredOutput/ResultConverter.php

@@ -11,12 +11,14 @@
 
 namespace Symfony\AI\Platform\StructuredOutput;
 
+use Symfony\AI\Platform\Exception\RuntimeException;
 use Symfony\AI\Platform\Model;
 use Symfony\AI\Platform\Result\ObjectResult;
 use Symfony\AI\Platform\Result\RawResultInterface;
 use Symfony\AI\Platform\Result\ResultInterface;
 use Symfony\AI\Platform\Result\TextResult;
 use Symfony\AI\Platform\ResultConverterInterface;
+use Symfony\Component\Serializer\Exception\ExceptionInterface as SerializerExceptionInterface;
 use Symfony\Component\Serializer\SerializerInterface;
 
 final readonly class ResultConverter implements ResultConverterInterface
@@ -41,8 +43,14 @@ public function convert(RawResultInterface $result, array $options = []): Result
             return $innerResult;
         }
 
-        $structure = null === $this->outputClass ? json_decode($innerResult->getContent(), true)
-            : $this->serializer->deserialize($innerResult->getContent(), $this->outputClass, 'json');
+        try {
+            $structure = null === $this->outputClass ? json_decode($innerResult->getContent(), true, flags: \JSON_THROW_ON_ERROR)
+                : $this->serializer->deserialize($innerResult->getContent(), $this->outputClass, 'json');
+        } catch (\JsonException $e) {
+            throw new RuntimeException('Cannot json decode the content.', previous: $e);
+        } catch (SerializerExceptionInterface $e) {
+            throw new RuntimeException(\sprintf('Cannot deserialize the content into the "%s" class.', $this->outputClass), previous: $e);
+        }
 
         $objectResult = new ObjectResult($structure);
         $objectResult->setRawResult($result);