Good idea or bad idea?

gistfile1.rb

#
# rspec shared examples for standard resource post to /create handling
#
# usage:
#   it_should_behave_like "handles POST create"
#
# good idea or bad?
#
shared_examples_for 'handles POST create' do
  before :all do
    @attributes = {'foo' => 'bar'}
  end

  before :each do
    @model_type_name ||= controller.class.name[0..-11].singularize
    @underscored_name ||= @model_type_name.underscore
    @model_type ||= @model_type_name.constantize
    @model = mock_model(@model_type_name.constantize)
    @model_type.stub(:new).with(@attributes) {@model}
    @was_saved = false
  end

  describe "with valid params" do
    before do
      save_returns true
      post_to_create
    end

    it "should create a new model" do
      @was_saved.should == true
    end

    it "should assign the newly created model" do
      assigns(@underscored_name).should be(@model)
    end

    it "should redirect to the newly created model" do
      response.should redirect_to(@model)
    end
  end

  describe "with invalid params" do
    before do
      save_returns false
      post :create, @underscored_name => @attributes
    end

    it "assigns a newly created but unsaved property as @property" do
      assigns(@underscored_name).should be @model
    end

    it "re-renders the 'new' template" do
      response.should render_template("new")
    end
  end


  def save_returns(result)
    @model.stub(:save) {@was_saved = true; result}
  end

  def post_to_create
    post :create, @underscored_name => @attributes
  end
end