require "spec_helper"
require "ruby_ext/multiple_inheritance"

describe "Multiple Inheritance" do
  after :each do
    remove_constants %w(M A M2 B AddedAfterInheritance)
  end

  it "showcase" do
    module M
      def instance_method; end

      class_methods do
        def class_method; end
      end

      def self.inherited target      
        target.send :attr_accessor, :some_accessor
      end
    end     
           
    M.should respond_to(:class_method)

    class A
      inherit M
    end
    
    A.should respond_to(:class_method)
    A.new.should respond_to(:instance_method)
    A.new.should respond_to(:some_accessor)
    
    M.directly_included_by.should == [A].to_set    
  end  

  it "should inherit all ancestors class methods" do
    module M
      def instance_method; end

      class_methods do        
        def class_method; end
      end
    end
    
    module M2
      inherit M

      class_methods do
        def class_method2; end
      end
    end

    class B
      inherit M2
    end
    
    M2.should respond_to(:class_method)
    
    B.should respond_to(:class_method)
    B.should respond_to(:class_method2)
    B.new.should respond_to(:instance_method)
    
    M.directly_included_by.should == [M2].to_set
    M2.directly_included_by.should == [B].to_set
  end
  
  it "shouldn't redefine ancestors class methods" do
    module M
      class_methods do
        def class_method; end
      end
    end
    
    module M2
      inherit M

      class_methods do
        def class_method2; end
      end
    end
    
    class A
      inherit M
    end
    
    A.should_not respond_to(:class_method2)
  end
  
  it "should also allow to explicitly use ClassMethods prototype (from error)" do
    module A
      module ClassMethods
        attr_accessor :callbacks
      end
    end
    
    class B
      inherit A
    end
    
    B.should respond_to(:callbacks)
  end
  
  it "methods defined on base class after inheritance must be propagated to all descendants" do
    module M; end            
    
    class A
      inherit M
    end
    
    A.instance_methods.should_not include('method_added_after_inheritance')
    M.send(:define_method, :method_added_after_inheritance){}
    M.instance_methods.should include('method_added_after_inheritance')
    A.instance_methods.should include('method_added_after_inheritance')
  end
  
  it "modules included in base class after inheritance must be propagated to all descendants" do
    module M; end
    
    class A
      inherit M
    end
    
    module AddedAfterInheritance
      def module_added_after_inheritance; end
    end
    
    M.instance_methods.should_not include('module_added_after_inheritance')
    M.inherit AddedAfterInheritance
    M.instance_methods.should include('module_added_after_inheritance')
    A.instance_methods.should include('module_added_after_inheritance')
  end
end