Hmm.

test.rb

context "a thing" do
  setup do
    @mailer = TestMailer.new
    @thing = Thing.new(@mailer)
  end

  should "send an email when poked" do
    @mailer.expects(:send_email)
    @thing.poke
  end

  should "increase the poke count" do
    previous_poke_count = @thing.poke_count
    @thing.poke
    assert_equal previous_poke_count + 1, @thing.poke_count
  end

  should "be marked as poked" do
    @thing.poke
    assert @thing.poked?
  end
end

# vs

context "a thing" do
  setup do
    @mailer = TestMailer.new
    @thing = Thing.new(@mailer)
  end

  doing { @thing.poke }

  expect "an email to be sent" { @mailer.expects(:send_email)}

  should_change { @thing.poke_count }

  should "be marked as poked" { assert @thing.poked? }
end