Tidying scaffolded Rails controller spec with subject/let
Check the answer from Pavel Druzyak for a different question. It answers your question as well. 

Your code can be refactored to this;

describe ProjectsController do
    let(:project) { Project.create! }

    describe "GET index" do
      before(:each) { get :index }
      it { should respond_with(:success) }
      it { should assign_to(:projects).with([project]) }
    end

    describe "GET show" do
      before(:each) { get :show, {:id =&gt; @project.to_param} }
      it { should respond_with(:success) }
      it { should assign_to(:projects).with(project) }
    end
end