Signed cookies and Test:unit don't mix: "NoMethodError" - unit-testing

Question

I am using signed cookies to maintain my user across pages, pretty much implemented as here.
I use two methods, sign_in(account) and sign_out to manipulate my cookies, creating or destroying them as you would expect ...
module SessionsHelper
def sign_in account
cookies.signed[:auth_account] = {
:expires => 1.week.from_now,
:value => [account.id, account.hash]
}
end
def sign_out
cookies.delete(:auth_account)
end
end
However, when trying to use this method, or the authenticate method that matches it in the ApplicationController from the functional tests, I get a NoMethodError:
NoMethodError: undefined method `signed' for {}:ActiveSupport::HashWithIndifferentAccess
I realise from this and this that this is an issue with the way cookies are defined differently in the test case, but I can't get any of these solutions to work. For completeness, an example test that fails with the above error:
require 'test_helper'
class AccountsControllerTest < ActionController::TestCase
include SessionsHelper
setup do
# We need to fake authentication by manually
# assigning an account to the sign_in process
sign_in accounts(:ia)
#account = accounts(:ia)
end
test "should 403 on index if unauthenticated" do
sign_out
get :index
assert_response :forbidden
end
test "should 200 on index if authenticated" do
get :index
assert_response :success
end
end

Answer 1

You can't set cookies in your test with the cookies variable like you do in your controller.
The cookies variable in your tests is use for read cookies after doing requests call (get/post...) and not for writing
In order to spoof login within your tests you should set cookies via #request.cookies[:auth]
you can put the following method in your test_helper and use it in all your tests
def signin user
#request.cookies[:auth] = user.auth
end
and in your tests
test "get dashboard if logged in" do
signin #user
get :index
end