#in my spec helper
def expose(name, &block)
  exhibitionist = Module.new
  exhibitionist.send(:define_method, name, &block)
  view.extend exhibitionist
end

# in my view spec
describe "dashboard/index.html.haml" do
  it 'renders' do
    expose(:foo) { 'bar' }
    rendered.should contain('bar')
  end
end