rspec let method + loop

i am having trouble running my rspec examples in a loop.

  describe "GET all providers" do
     let(:current_user) { Factory(:user) }
 
     [:twitter, :facebook, :google_oauth2].each do |provider|
       before :each do
         current_user.confirm!
         sign_in current_user
 
         request.env['devise.mapping'] = Devise.mappings[:user]
         request.env["omniauth.auth"] = OmniAuth.config.add_mock provider, {
           :uid => '123456789',
           :info => {
             :email => current_user.email
           }
         }
       end
 
       it 'should add the authorization' do            
         get provider # method to create the authorization
         authorization = Authorization.where(:provider => request.env["omniauth.auth"][:provider], :uid => request.env["omniauth.auth"][:uid]).first
         current_user.authorizations.should include authorization
       end
     end
   end
 

currently these examples all pass. the problem though is that current_user is a new user instance through each iteration of the loop, despite memoizing the current_user method. so if i add a test for current_user.authorizations.count.should == 3 it fails.

this became less of needing to actually test it, and more understanding why it isnt behaving how i expect. shouldn't let(:current_user) { Factory(:user) } persist the same user instance across all examples?

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