Can't access session attributes

I’m using acts_as_authenticated, and I’m trying to run some tests where
the user must be registered. In the past, I’ve just included a user id
in the session data.

def test_login_loads_from_post_session
post :new, nil, { :user => 7 }
session = assigns(:session)
assert_equal 7, session[:user]

My assert statement seems to be failing because my session is not
showing me as being logged in.

Executing break point at
in `login_required’
irb(#LinksController:0x2481fec):001:0> session
=> #<ActionController::TestSession:0x24805fc @attributes={:user=>7,
“flash”=>{}}, saved_attributesnil, session_id""
irb(#LinksController:0x2481fec):002:0> session[:user]
=> nil

What I don’t understand is why I can’t access the attributes that are
listed in the session object. You can see that the @attributes hash has
the value 7 for the key :user.

What am I doing wrong?