a simple sign_in & sign_out machinery for an app I'm currently working on. I try to follow good OO design & separation of concerns, etc. & extract domain objects as much as possible & have fast-isolated tests. But can't stub simple methods of a module in

current_version_sign_in_out_spec.rb

module SessionsHelper
    include SignInOut

    def create_cookie(user_id, user_salt); end

    def remember_token; end

    def delete_cookie; end
end

describe "Sign in and out" do
    include SessionsHelper 

    it "signs the user in" do
        user = stub(:id => stub)
        user.stub(:salt => stub)
        sign_in(user)
        signed_in?.should be_true
    end

    ...

    #but as you can see this is so fragile and whenever I have a new method in SessionsHelper I have to define a stub one in the SessionsHelper in the spec
    #also I can't express the expectations on its methods and stub some results for better live documentation style of specs and expressing stuff explicitly
    #in my specs
end

sign_in_out.rb

#This module will be included in SessionsHelper where cookies and remember_token stuff exists
module SignInOut
    def sign_in(user)
        create_cookie(user.id, user.salt)
        @current_user = user
    end

    def current_user
        @current_user || user_from_remember_token
    end

    def signed_in?
        !@current_user.nil?
    end

    def sign_out
        delete_cookie
        @current_user = nil
    end

    def user_from_remember_token
        AuthenticateUser.authenticate_with_salt(*remember_token)
    end
end

module SessionsHelper
    include SignInOut

    def create_cookie(user_id, user_salt)
        cookies.permanent.signed[:remember_token] = [user_id, user_salt]
    end

    def remember_token
        cookies.signed[:remember_token] || [nil, nil]
    end

    def delete_cookie
        cookies.delete(:remember_token)
    end
end

sign_in_out_spec.rb

module SessionsHelper
    include SignInOut #because it assumed cookies related methods will be in SessionsHelper it should be included in this for simulating the production code
end

describe "Sign in and out" do
    include SessionsHelper

    #I want to be able to stub some methods in SessionsHelper (or any module like this scenario) and express some call expectations like the following
    it "creates the cookie and signs the user in" do
        user = stub(:id => 1)
        user.stub(:salt => "salt")
        SessionsHelper.stub(:create_cookies).with(1, "salt")
        sign_in(user)
        signed_in?.should be_true
    end

    #And doing this kind of stubbing on the SessinosHelper methods like delete_cookie, remember_token, etc. (or methods of any other module like this scenario)

end

Only self methods in a module can be stubbed out this way (like the last file spec example) but I need to stub out simple methods of a module like the create_cookie for instance in the SessionsHelper and I don't know how to do it!

Ouch, that double include is crazy :/

@steveklabnik I know it's not a good idea doing this. I finally figured it out how to do this. I can do something like the following for better and cleaner testing for this:
describe "Sign in and out" do
let(:sessions_helper) { stub.extend(SignInOut) }

it "creates cookie for the user" do
user_id, user_salt = 1, "salt"
user = stub(:id => user_id, :salt => user_salt)
sessions_helper.should_receive(:create_cookie).with(user_id, user_salt)
sessions_helper.sign_in(user)
end

....
end

this is a better and less confusing way. Thanks to @garybernhardt for the hint.
Thank you Steve for the review, I appreciate that ;)