class Rack::Test::UploadedFile

buffer.
after to make sure all data in tempfile is appended to the
copies of file data in memory. Rewind tempfile before and
Append to given buffer in 64K chunks to avoid multiple large

def append_to(buffer)
  tempfile.rewind
  buf = String.new
  buffer << tempfile.readpartial(65_536, buf) until tempfile.eof?
  tempfile.rewind
  nil
end