require "test_helper" class QrCodeControllerTest < ActionDispatch::IntegrationTest test "show renders a QR code as a cacheable SVG image" do id = Base64.urlsafe_encode64("http://example.com") get qr_code_path(id) assert_response :success assert_includes response.content_type, "image/svg+xml" assert_equal 1.year, response.cache_control[:max_age].to_i assert response.cache_control[:public] end end