Organizing stages of test

users_controller_spec.rb

# Before: expectations are set before and after subject; 
# whole code is in one chunk
describe UsersController do
  describe "#create" do
    it "uses UserForm to persist user" do
      user = create(:user, name: "Mike")
      expect(UserForm).to receive(:call).with(kind_of(User), name: "Tony")
      put :update, params: { id: user.id, user: { name: "Tony" } }
      expect(response).to be_ok
    end
  end
end

# After: expectations are set after calling subject; 
# stages are separated with blank lines
describe UsersController do
  describe "#update" do
    it "uses UserForm to persist user" do
      user = create(:user, name: "Mike")
      allow(UserForm).to receive(:call).and_call_original

      put :update, params: { id: user.id, user: { name: "Tony" } }

      expect(response).to be_ok
      expect(UserForm).to have_received(:call).with(kind_of(User), name: "Tony")
    end
  end
end