Make possible to be strict about format in JsonBodyListener

[shouze]

Description

Steps to reproduce the issue:

1. Have a Symfony controller action that return this kind of response:

return new JsonResponse(['key' => $request->get('key')]);

2. then request this action like that:

# We don't set any Accept nor Content-Type header
curl -d '{"key": "value"} http://domain.tld/path 

Describe the results you received:

HTTP/1.1 200 OK

{"key": null}

Describe the results you expected:

HTTP/1.1 406 Not Acceptable

Note: Here we consider that we implement HTTP content negociation the right way so the client must provide a Content-Type header.

From where to start

The actual part of JsonBodyListener incrimined code is:

https://github.com/rezzza/symfony-json-rest-api/blob/67639f9383eb4637f6ea56eed136af5373282428/src/JsonBodyListener.php#L34-L40

Other source(s) to watch for inspiration

FOSRestBundle FormatListener.php#L58-L75:

            $format = $request->getRequestFormat(null);
            if (null === $format) {
                $accept = $this->formatNegotiator->getBest('');
                if (null !== $accept && 0.0 < $accept->getQuality()) {
                    $format = $request->getFormat($accept->getValue());
                    if (null !== $format) {
                        $request->attributes->set('media_type', $accept->getValue());
                    }
                }
            }

            if (null === $format) {
                if ($event->getRequestType() === HttpKernelInterface::MASTER_REQUEST) {
                    throw new NotAcceptableHttpException('No matching accepted Response format could be determined');
                }

                return;
            }

[tyx]

We need the routing part

[shouze]

ping @tyx I guess this is closed by #21 and #23?