Overrides the cookies() method in
ActionController::TestResponseBehaviour, returning a proxy that accesses
the requests cookies when
setting a cookie and the responses cookies when reading one.
This allows you to set and read cookies in examples using
the same API with which you set and read them in controllers.
Examples (Rails >= 1.2.6)
cookies[:user_id] = '1234'
get :index
assigns[:user].id.should == '1234'
post :login
cookies[:login].expires.should == 1.week.from_now
Examples (Rails >= 2.0.0 only)
cookies[:user_id] = {:value => '1234', :expires => 1.minute.ago}
get :index
response.should be_redirect