避免在RSpec中重新创建主题

Say I have the following test

说我有以下测试

describe "bob" do
  subject { 
    response = get "/expensive_lookup"
    JSON.parse(response.body) 
  }

  its(["transaction_id"]) { should == 1 }
  its(["order_id"]) { should == 33 }
end
descr