Would controller specs be better?

test/controllers/document_collection_email_notifications_controller_test.rb

@@ -0,0 +1,29 @@
+require "test_helper"
+
+class ContentItemsControllerTest < ActionController::TestCase
+  include GdsApi::TestHelpers::ContentStore
+  include GovukPersonalisation::TestHelpers::Requests
+
+  test "the single page notification button POSTs to EmailAlertAPI's account-only endpoint for users logged into their gov.uk account" do
+    content_item = content_store_has_schema_example("document_collection", "document_collection")
+    stub_content_store_has_item(content_item["base_path"], content_item)
+    path = content_item["base_path"][1..]
+
+    mock_logged_in_session("session_id")
+    get :show, params: { path: }
+
+    assert response.body.include?("/email/subscriptions/single-page/new")
+    assert response.body.include?("gem-c-single-page-notification-button")
+  end
+
+  test "the single page notification button POSTs to EmailAlertAPI's account-free endpoint if users do not have an active account session" do
+    content_item = content_store_has_schema_example("document_collection", "document_collection")
+    stub_content_store_has_item(content_item["base_path"], content_item)
+    path = content_item["base_path"][1..]
+
+    get :show, params: { path: }
+
+    assert response.body.include?("/email-signup")
+    assert response.body.include?("gem-c-single-page-notification-button")
+  end
+end