rspecでETagのテストを追加した

背景

Android端末とサーバーの同期（一方通行）を実装するために、ETagを使いました。サーバーのコードを変更したため、テストを追加した

サーバー側

def sync
    return unless stale?(@program)

    render json: { success: 1, data: @program }
  end

Rspec

context "on a subsequent request" do
      before(:each) do
        # first time request
        get api_sync_path, params: { device_id: device.id }
        assert_response 200, response.body
        @etag = response.headers["ETag"]
      end

      context "check ETag exist" do
        it 'both should exist' do
          expect(@etag).to be_present
        end
      end

      context 'when no update' do
        before(:each) do
          @headers = { "ACCEPT" => "application/json", "HTTP_IF_NONE_MATCH" => @etag }
        end

        it 'should return 304' do
          get api_sync_path, params: { device_id: device.id }, headers: @headers
          assert_response 304, response.body
        end
      end

      context 'when there is update' do
        before(:each) do
          @headers = { "ACCEPT" => "application/json", "HTTP_IF_NONE_MATCH" => @etag }
          # program_slot.touchだと時間が短すぎて、変わらない可能性がある
          program_slot.update(updated_at: 1.hour.from_now)           
        end

        it 'should return 200' do
          get api_sync_path, params: { device_id: device.id }, headers: @headers
          assert_response 200, response.body
        end
      end
    end

参考

• Caching with Rails: An Overview — Ruby on Rails Guides
• Introduction to Conditional HTTP Caching with Rails
• request spec - Request specs - RSpec Rails - RSpec - Relish