RSpec - Having trouble mocking model associations

Hi everyone,

I'm having a devil of a time trying to figure out why this spec keeps giving me an error. I'm attempting to mock out a class I haven't created yet (User) so I don't need to worry about creating it at the moment. I could have sworn I read somewhere that it was possible to pass a mock object as an attribute to an associated class, but it's just not working for me.

Here's the code I have:

# task_spec.rb describe Task do   before(:each) do     user_proxy = mock('user')     @task = Task.new(       :description => "Sample task description",       :assigned_user => user_proxy     )   end      it "should be valid with all required attributes" do     @task.should be_valid   end      it "should be invalid without a description" do     @task.description = nil     @task.should_not be_valid     @task.should have(1).error_on(:description)   end      it "should be invalid unless assigned to a user" do     @task.assigned_user = nil     @task.should_not be_valid     @task.should have(1).error_on(:assigned_user_id)   end end

# task.rb class Task < ActiveRecord::Base   belongs_to :assigned_user, :class => "User", :foreign_key => "assigned_user_id"      validates_presence_of :description   validates_presence_of :assigned_user_id # Validate against the foreign key, not the association end