Symfony version(s) affected

6.2.10

Description

The SerializerErrorRenderer class cannot extract a csv acceptable header from a request. The static method SerializerErrorRenderer::getPreferredFormat delegates that work to the Request->getPreferredFormat method which is unable to return "csv" because static::$formats doesn't contain information about "csv" format (in the case when request attribute "_format" is not set explicitly).

How to reproduce

Create a controller that throws any exception.

#[Route('/exception', name: 'app_exception')]
public function exception(Request $request): Response
{
    throw new \Exception('boom!');
}

Run a cURL request including the "Accept: text/csv" header.

curl -X GET -i --header 'Accept: text/csv' http://localhost:8000/exception

Expected result:

content-type: text/csv; charset=UTF-8
...
[CSV encoded body]

Actual result:

content-type: text/html; charset=UTF-8
...
[HTML encoded body]

Possible Solution

Add a 'csv' => ['text/csv', 'application/csv', 'text/x-comma-separated-values', 'text/x-csv'], line into initializeFormats method of Request class.

    protected static function initializeFormats()
    {
        static::$formats = [
            'html' => ['text/html', 'application/xhtml+xml'],
            'txt' => ['text/plain'],
            'js' => ['application/javascript', 'application/x-javascript', 'text/javascript'],
            'css' => ['text/css'],
            'json' => ['application/json', 'application/x-json'],
            'jsonld' => ['application/ld+json'],
            'xml' => ['text/xml', 'application/xml', 'application/x-xml'],
            'rdf' => ['application/rdf+xml'],
            'atom' => ['application/atom+xml'],
            'rss' => ['application/rss+xml'],
            'form' => ['application/x-www-form-urlencoded', 'multipart/form-data'],
            'csv' => ['text/csv', 'application/csv', 'text/x-comma-separated-values', 'text/x-csv'],
        ];
    }

Additional Context

Everything works fine when the format is explicitly set in a preview mode i.e.

curl -X GET -i --header 'Accept: text/csv' http://localhost:8000/_error/500.csv

The request attribute "_format" is set to "csv" in this case.