UploadedFile.rb

# I wonder why we still use File instance monkey-patching 
# instead of a regular subclass/delegator?
# Every time you test uploaded files, you come up with a brand-new mock.
# Duh...
class UploadedFile < Delegator
  attr_accessor :file, :mime_type, :original_filename
  
  def initialize(file, mime_type, original_filename)
    super(file)
    @file              = file
    @mime_type         = mime_type
    @original_filename = original_filename
    # ...
  end
  
  def __getobj__; @file; end # required by Delegator
end