Multipart/form-data and PUT method

Hi,

I’m testing this two javascript lines :

fetch(form.getAttribute('action'), {method: 'POST', body: new FormData(form)});
fetch(form.getAttribute('action'), {method: 'PUT', body: new FormData(form)});

In first case, ServerRequest::getData() or ServerRequest::getParsedBody() contains the form data.

In second case, it’s empty.
I can fix with a new URLSearchParams(new FormData(form)). Ok.

But there is a reason why only POST data support the multipart/form-data ?
source : cakephp/ServerRequestFactory.php at 3653648f88a14f526665f6b0d0b156ea868b4e88 · cakephp/cakephp · GitHub

Thanks.