Question

I have the following ActiveRecord classes:

class User < ActiveRecord::Base   cattr_accessor :current_user   has_many :batch_records end  class BatchRecord < ActiveRecord::Base   belongs_to :user    named_scope :current_user, lambda {     { :conditions => { :user_id => User.current_user && User.current_user.id } }   } end 

and I’m trying to test the named_scope :current_user using Shoulda but the following does not work.

class BatchRecordTest < ActiveSupport::TestCase   setup do     User.current_user = Factory(:user)   end    should_have_named_scope :current_user,                           :conditions => { :assigned_to_id => User.current_user } end 

The reason it doesn’t work is because the call to User.current_user in the should_have_named_scope method is being evaluated when the class is being defined and I’m change the value of current_user afterwards in the setup block when running the test.

Here is what I did come up with to test this named_scope:

class BatchRecordTest < ActiveSupport::TestCase   context 'with User.current_user set' do     setup do       mock_user = flexmock('user', :id => 1)       flexmock(User).should_receive(:current_user).and_return(mock_user)     end      should_have_named_scope :current_user,                             :conditions => { :assigned_to_id => 1 }   end end 

So how would you test this using Shoulda?

Answer 1

I think you are going about this the wrong way. Firstly, why do you need to use a named scope? Wont this just do?

class BatchRecord < ActiveRecord::Base   belongs_to :user    def current_user     self.user.class.current_user   end end 

In which case it would be trivial to test. BUT! WTF are you defining current_user as a class attribute? Now that Rails 2.2 is ‘threadsafe’ what would happen if you were running your app in two seperate threads? One user would login, setting the current_user for ALL User instances. Now another user with admin privileges logs in and current_user is switched to their instance. When the first user goes to the next page he/she will have access to the other persons account with their admin privileges! Shock! Horror!

What I reccomend doing in this case is to either making a new controller method current_user which returns the current user’s User instance. You can also go one step further and create a wrapper model like:

class CurrentUser    attr_reader :user, :session    def initialize(user, session)     @user, @session = user, session   end    def authenticated?     ...   end    def method_missing(*args)     user.send(*args) if authenticated?   end  end 

Oh, and by the way, now I look at your question again perhaps one of the reasons it isn’t working is that the line User.current_user && User.current_user.id will return a boolean, rather than the Integer you want it to. EDIT I’m an idiot.

Named scope is really the absolutely wrong way of doing this. Named scope is meant to return collections, rather than individual records (which is another reason this fails). It is also making an unnecessary call the the DB resulting in a query that you don’t need.