[HttpFoundation] JsonResponse content updated

[MehGokalp]

When using the JsonResponse with customized encoding options, the JsonResponse class can modify the given data.
Example:

$response = new JsonResponse(['data' => (float) 3]);
echo $response->getContent(); // {"data": 3}
$response->setEncodingOptions(JsonResponse::DEFAULT_ENCODING_OPTIONS | \JSON_PRESERVE_ZERO_FRACTION);
echo $response->getContent(); // {"data": 3}

as you can see we gave float value and it returns integer. Because when we instantiate the JsonResponse it serializes the data with default encoding options. The proper way to do this;

$response = new JsonResponse();
$response->setEncodingOptions(JsonResponse::DEFAULT_ENCODING_OPTIONS | \JSON_PRESERVE_ZERO_FRACTION);
$response->setData(['data' => (float) 3]);
echo $response->getContent(); // {"data": 3.0}

for details of the \JSON_PRESERVE_ZERO_FRACTION flag see https://www.php.net/manual/en/function.json-encode.php

[wouterj]

Thank you @MehGokalp! I've slightly modified the comments (to make them a bit shorter) and merged your contribution in 4.4. We'll take care of bringing it to the newer versions from there.