How the simples thing (its gem) makes specs much easier to read

controller_spec_plain.rb

# Controller spec using plain old matchers


describe "#create" do
  let(:participation) { stub 'Participation' }
  let(:params) { {:participation => {}} }
  before { InviteUser.stub(:into_company_by_params => participation) }

  context "with success" do
    before { participation.stub(:valid? => true) }
    it "should assign participation" do
      get(:create, params)
      assigns(:participation).should == participation
    end
    it "should should redirect" do
      get(:create, params).should be_redirect
    end
  end

  context "with failure" do
    before { participation.stub(:valid? => false) }
    before { participation.should_receive(:available_developments).and_return devs }
    let(:devs) { [stub, stub] }

    it "should assign participation" do
      get(:create, params)
      assigns(:participation).should == participation
    end
    it "should render template" do
      get(:create, params).should render_template :new
    end
  end
end

controller_spec_using_its.rb

# Controller spec using `its` gem


describe "#create" do
  let(:participation) { stub 'Participation' }
  let(:params) { {:participation => {}} }
  before { InviteUser.stub(:into_company_by_params => participation) }
  subject { get(:create, params); self }

  context "with success" do
    before { participation.stub(:valid? => true) }
    its(:assigns, :participation) { should == participation }
    its(:response) { should be_redirect }
  end

  context "with failure" do
    before { participation.stub(:valid? => false) }
    before { participation.should_receive(:available_developments).and_return devs }
    let(:devs) { [stub, stub] }

    its(:assigns, :participation) { should == participation }
    its(:response) { should render_template :new }
  end
end

For curious ones, the gem to allow this is its.