how to send a multipart post?

photos_controller_test.rb

  test "should create photo" do
    assert_difference('Photo.count') do
      post :create, :album_id => albums(:gallery_one_one).to_param, :photo => {:name => 'photo_fooooo', :description => 'bar', :image => fixture_file_upload('rails.png')}
    end

    assert_redirected_to admin_album_photos_path(assigns(:album))
  end