[Platform] StructuredOutput use Serializer to hydrate values but rely on ReflectionProperty for the schema

[VincentLanglet]

Hi @chr-hertel @OskarStark

I just found a bug which is easy to reproduce with

framework:
    serializer:
        enabled: true
        enable_attributes: true
        name_converter: 'serializer.name_converter.camel_case_to_snake_case'

And an output class like

class Foo
{
    public function __construct(public string $fooBar) {}
}

When using

$content = $this->agent->call($messages, [
            'response_format' => Foo::class,
])->getContent();

The schema is generated using the ReflectionProperty

ai/src/platform/src/Contract/JsonSchema/Factory.php

Lines 87 to 89 in 5e1d943

	$reflection = new \ReflectionClass($className);
	return $this->convertTypes($reflection->getProperties());

so considered the field as fooBar
But the data is hydrated with the serializer

ai/src/platform/src/StructuredOutput/ResultConverter.php

Line 48 in 5e1d943

: $this->serializer->deserialize($innerResult->getContent(), $this->outputType, 'json');

so the serializer name converter is used and it will expect a foo_bar key instead of fooBar.

Currently the workaround is to do

class Foo
{
    public function __construct(
       #[SerializedName('fooBar')]
       public string $fooBar
    ) {}
}

Any clue on how to fix this ? Maybe the PlatformSubscriber shouldn't rely on the default serialzer of Symfony ?

[chr-hertel]

yea, agree, as long as that process is that opinionated (and i think that's fair), it should basically just use it's own serializer.

at least that seems more straight forward than using the name_converter while generating the schema - could also be a solution tho

[VincentLanglet]

I dunno if symfony/ai could defined a custom serializer (with named serializer ? https://symfony.com/doc/current/serializer.html#named-serializers) rather than using the default one.

at least that seems more straight forward than using the name_converter while generating the schema - could also be a solution tho

Yeah it's unclear to me how to do this...

as long as that process is that opinionated (and i think that's fair), it should basically just use it's own serializer.

How do you want me to do this @chr-hertel ? Just removing the injection of serializer in PlatformSubscriber to rely on the custom instantiation ?

ai/src/platform/src/StructuredOutput/PlatformSubscriber.php

Line 45 in c416210

private ?SerializerInterface $serializer = null,

Btw, the fact Factory doesn't rely on serializer still create a weird situation where, if I write

public function __construct(
       #[SerializedName('something')]
       public string $fooBar
    ) {}

it will break serialization...

Also I dunno if other injections are suffering the same issue

ai/src/ai-bundle/config/services.php

Lines 149 to 155 in c416210

	->set('ai.tool_result_converter', ToolResultConverter::class)
	->args([
	service('serializer'),
	])
	->set('ai.tool_call_argument_resolver', ToolCallArgumentResolver::class)
	->args([
	service('serializer'),

[VincentLanglet]

I tried a PR #940