+++ This bug was initially created as a clone of Bug #161190 +++ This bug is to implement the .formData() method defined here: https://fetch.spec.whatwg.org/#dom-body-formdata This will require parsing multipart/form-data. It seems WebKit has an existing multipart parser here that I'll try to use: https://github.com/WebKit/webkit/blob/master/Source/WebCore/platform/network/curl/MultipartHandle.h
This is now supported.