Some POST on ApiResource with async messenger and output false are broken in 3.3

[MariusJam]

API Platform version(s) affected: ^3.3

Description

A POST on a ApiResource with messenger: true, output: false raise an error 400 with message Unable to generate an IRI for the item of type... in some case :

• when no identifier is sent in the request body
• when using an async transport

This is working fine in 3.2.* and should not happened as we expect no output (there is no need to generate an IRI).

How to reproduce

With this resource and configuration:

namespace App\ApiResource;

use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\NotExposed;
use ApiPlatform\Metadata\Post;

#[ApiResource(operations: [
    new NotExposed(),
    new Post(status: 202, output: false, messenger: true)
])]
class Foo
{
    public ?int $id = null;
}

#messenger.yaml
framework:
    messenger:
        transports:
             async: '%env(MESSENGER_TRANSPORT_DSN)%'
        routing:
            App\ApiResource\Foo: async

Doing a POST with an empty body {} on /foos throw an error 400 Unable to generate an IRI for the item of type \"App\\Entity\\Foo\"

Possible Solution

There is a need to check before trying to generate an IRI that we actually expect an output. However, with the new architecture based on processors, I don't know where it would be the more appropriate.

Additional Context

I have been able to track the origin of the problem to this commit. The issue is due to the change of behaviour in WriteListener.php:

• in ^3.3, the WritePRocessor is called and $data is retrieved from there and passed to processors until the RespondProcessor is called and try to generate an IRI (L.111)
• in 3.2.*, we ensure we need an output before generating the IRI (L.114)

[soyuka]

nice thanks for the neat report @MariusJam !