let, let, let, let, let, let, let.

reports_controller_spec.rb

describe ReportsController do
  subject { last_response }
  
  describe :create do
    let(:payload) { { :serial => serial, :version => "1.0.0" } }
    before { post reports_path, payload.to_json }

    context "with present serial" do
      let(:serial) { "123abc" }

      it { should be_ok }
      its(:status) { should eq 200 }
    end

    context "with missing serial" do
      let(:serial) { nil }

      it { should_not be_ok }
      its(:status) { should eq 400 }
    end
  end
end