Dropzone: Rejected and accepted files on the same callback function (Proposed fix)

[nicolassanmar]

Context

Consider the following scenario, where a user uploads files to a dropzone and we want to keep track of the uploaded files:

const MyDropzoneComponent = () => {
  const [accepted, setAccepted] = useState([]);
  const [rejected, setRejected] = useState([]);
  
  return (
  <Dropzone onDrop={setAccepted} onReject={setRejected} accept={PDF_MIME_TYPE} />
  )
}

Problematic scenario

1. User tries to upload a single '.png' file. It will get rejected, setting the rejected variable by onReject
2. User uploads only '.pdf' files. This will only call onDrop since user did only upload valid files.

Problem

The final state of accepted and rejected do not reflect the last user drop

Solution

Add a new prop to the Dropzone called something like onDropAny that gets both accepted and rejected files. react-dropzone already provides this functionality so it should be easy to implement.
(it is called onDrop on the useDropzone hook)

This would make it possible to update the state of both accepted and rejected on the same function, guaranteeing to be able to set the state of the last user interaction

I am currently trying this on a fork!
This PR shows a way that this could be implemented:
#3010

[rtivital]

Added in 5.8.3