test_process.rb

require "action_dispatch/middleware/cookies"
require "action_dispatch/middleware/flash"

module ActionDispatch
  module TestProcess
    def assigns(key = nil)
      raise NoMethodError,
        "assigns has been extracted to a gem. To continue using it,
        add `gem 'rails-controller-testing'` to your Gemfile."
    end

    def session
      @request.session
    end

    def flash
      @request.flash
    end

    def cookies
      @cookie_jar ||= Cookies::CookieJar.build(@request, @request.cookies)
    end

    def redirect_to_url
      @response.redirect_url
    end

    # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.fixture_path, path), type)</tt>:
    #
    #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png')
    #
    # To upload binary files on Windows, pass <tt>:binary</tt> as the last parameter.
    # This will not affect other platforms:
    #
    #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png', :binary)
    def fixture_file_upload(path, mime_type = nil, binary = false)
      if self.class.respond_to?(:fixture_path) && self.class.fixture_path
        path = File.join(self.class.fixture_path, path)
      end
      Rack::Test::UploadedFile.new(path, mime_type, binary)
    end
  end
end