function fileAccepted(file, accept) {
  const isAcceptable =
    file.type === "application/x-moz-file" || accepts(file, accept);
  return [
    isAcceptable,
    isAcceptable ? null : getInvalidTypeRejectionErr(accept),
  ];
}
Check if file is accepted.

Firefox versions prior to 53 return a bogus MIME type for every file drag,
so dragovers with that MIME type will always be accepted.

@param {File} file
@param {string} accept
@returns