How to get fixtures data in describe scope

Question

Hi. I'm struggling with spec for generic shared-exapmle here. But I can't get fixtures data in describe scope.
Like below

describe BlogController do
  fixtures :blogs
  {
    :show=>{:month=>blogs(:one).month, :day=>blogs(:one).day},
    :edit=>{:month=>blogs(:one).month, :day=>blogs(:one).day}
  }.each |act, prams| do
    describe "blog/#{act}" do
    end
  end
end

How to get it?