Add warnings when deleting questions that are associated with routes

app/controllers/pages_controller.rb

@@ -16,7 +16,34 @@ def delete
     @item_name = @page.question_text
     @back_url = edit_question_path(current_form.id, @page.id)
 
+    all_form_conditions = current_form.pages.flat_map(&:routing_conditions).compact_blank
+    @page_goto_conditions = all_form_conditions.select { |condition| condition.goto_page_id == @page.id }
+
+    if @page.routing_conditions.any? && @page.routing_conditions.first.secondary_skip?
+      @routing = :start_of_secondary_skip_route
+
+      # route owner is condition check page
+      @route_owner = PageRepository.find(page_id: @page.routing_conditions.first.check_page_id, form_id: current_form.id)
+    elsif @page.routing_conditions.any?
+      @routing = :start_of_route
+
+      # route owner is us
+      @route_owner = @page
+    elsif @page_goto_conditions.any? && @page_goto_conditions.first.secondary_skip?
+      @routing = :end_of_secondary_skip_route
+
+      # route owner is condition check page
+      @route_owner = PageRepository.find(page_id: @page_goto_conditions.first.check_page_id, form_id: current_form.id)
+    elsif @page_goto_conditions.any?
+      @routing = :end_of_route
+
+      # route owner is condition routing page
+      @route_owner = PageRepository.find(page_id: @page_goto_conditions.first.routing_page_id, form_id: current_form.id)
+    end
+
     @delete_confirmation_input = Forms::DeleteConfirmationInput.new
+
+    render locals: { current_form: }
   end
 
   def destroy
@@ -35,7 +62,7 @@ def destroy
         redirect_to @back_url
       end
     else
-      render :delete
+      render :delete, locals: { current_form: }
     end
   rescue StandardError
     flash[:message] = "Deletion unsuccessful"

app/views/pages/delete.html.erb

@@ -3,6 +3,21 @@
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
+
+    <% unless @delete_confirmation_input.errors.any? %>
+      <% if @routing.present? %>
+        <%= govuk_notification_banner(title_text: "Important") do |banner|
+          banner.with_heading(text: t(".notification_banner.#{@routing}.heading_text", page_position: @page.position), tag: :h3)
+
+          t(
+            ".notification_banner.#{@routing}.html",
+            route_owner_position: @route_owner.position,
+            show_routes_href: show_routes_path(current_form.id, @route_owner.id),
+          )
+        end %>
+      <% end %>
+    <% end %>
+
     <%= render(
       @delete_confirmation_input,
       url: @url,

config/locales/en.yml

@@ -1133,6 +1133,35 @@ en:
   pages:
     answer_settings: Answer settings
     delete:
+      notification_banner:
+        end_of_route:
+          heading_text: Question %{page_position} is at the end of a route
+          html: |
+            <p class="govuk-body">
+              <a class="govuk-notification-banner__link" href="%{show_routes_href}">Question %{route_owner_position}’s route</a>
+              goes to this question. If you delete this question, question %{route_owner_position}’s routes will also be deleted.
+            </p>
+        end_of_secondary_skip_route:
+          heading_text: Question %{page_position} is at the end of a route
+          html: |
+            <p class="govuk-body">
+              <a class="govuk-notification-banner__link" href="%{show_routes_href}">Question %{route_owner_position}’s route</a>
+              goes to this question. If you delete this question, the route to it will also be deleted.
+            </p>
+        start_of_route:
+          heading_text: Question %{page_position} is the start of a route
+          html: |
+            <p class="govuk-body">
+              If you delete this question, its routes will also be deleted.
+              <a class="govuk-notification-banner__link" href="%{show_routes_href}">View question %{route_owner_position}’s routes</a>.
+            </p>
+        start_of_secondary_skip_route:
+          heading_text: Question %{page_position} is the start of a route
+          html: |
+            <p class="govuk-body">
+              <a class="govuk-notification-banner__link" href="%{show_routes_href}">Question %{route_owner_position}’s route</a>
+              starts at this question. If you delete this question, the route from it will also be deleted.
+            </p>
       title: Are you sure you want to delete this question?
     delete_question: Delete question
     go_to_your_questions: Back to your questions

spec/requests/pages_controller_spec.rb

@@ -1,7 +1,7 @@
 require "rails_helper"
 
 RSpec.describe PagesController, type: :request do
-  let(:form_response) { build :form, id: 2 }
+  let(:form_response) { Form.new(attributes_for(:form, id: 2), true) }
 
   let(:group) { create(:group, organisation: standard_user.organisation) }
   let(:membership) { create :membership, group:, user: standard_user }
@@ -82,24 +82,37 @@
   describe "#delete" do
     describe "given a valid page" do
       let(:page) do
-        Page.new({
+        build(
+          :page,
           id: 1,
           form_id: 2,
           question_text: "What is your work address?",
           hint_text: "This should be the location stated in your contract.",
           answer_type: "address",
           next_page: nil,
           is_optional: false,
-        })
+        )
       end
 
+      let(:pages) { [page] }
+
       before do
+        ActiveResource::HttpMock.respond_to do |mock|
+          mock.get "/api/v1/forms/2/pages", headers, pages.to_json, 200
+        end
+
         allow(FormRepository).to receive(:find).and_return(form_response)
-        allow(PageRepository).to receive_messages(find: page, destroy: true)
+
+        pages.each do |page|
+          allow(PageRepository).to receive(:find).with(page_id: page.id.to_s, form_id: 2).and_return(page)
+          allow(PageRepository).to receive(:find).with(page_id: page.id, form_id: 2).and_return(page)
+        end
+
+        allow(PageRepository).to receive_messages(destroy: true)
 
         GroupForm.create!(form_id: 2, group_id: group.id)
 
-        get delete_page_path(form_id: 2, page_id: 1)
+        get delete_page_path(form_id: 2, page_id: page.id)
       end
 
       it "renders the delete page template" do
@@ -117,6 +130,162 @@
           expect(response).to have_http_status :forbidden
         end
       end
+
+      context "when page to delete has no routes" do
+        it "does not render a warning" do
+          expect(response.body).not_to include "Important"
+        end
+      end
+
+      context "when page to delete is start of one or more routes" do
+        let(:page) do
+          build(
+            :page,
+            :with_selection_settings,
+            id: 1,
+            form_id: 2,
+            question_text: "What is your favourite colour?",
+            selection_options: [{ name: "Red" }, { name: "Green" }, { name: "Blue" }],
+            only_one_option: true,
+            routing_conditions: [
+              build(:condition, routing_page_id: 1, check_page_id: 1, value: "red", skip_to_end: true),
+              build(:condition, routing_page_id: 1, check_page_id: 1, value: "green", goto_page_id: 3),
+            ],
+          )
+        end
+
+        it "renders a warning about deleting this page" do
+          assert_select(".govuk-notification-banner", count: 1) do
+            assert_select "*", "Important"
+            assert_select "h3", "Question #{page.position} is the start of a route"
+            assert_select "p.govuk-body", /If you delete this question, its routes will also be deleted/
+            assert_select "p.govuk-body a", "View question #{page.position}’s routes"
+          end
+        end
+      end
+
+      context "when page to delete is at the end of a route" do
+        let(:pages) do
+          [
+            build(
+              :page,
+              :with_selection_settings,
+              id: 1,
+              form_id: 2,
+              position: 1,
+              question_text: "What is your favourite colour?",
+              selection_options: [{ name: "Red" }, { name: "Green" }, { name: "Blue" }],
+              only_one_option: true,
+              routing_conditions: [
+                build(:condition, routing_page_id: 1, check_page_id: 1, value: "green", goto_page_id: 3),
+              ],
+            ),
+            build(
+              :page,
+              id: 3,
+              form_id: 2,
+              position: 3,
+            ),
+          ]
+        end
+
+        let(:page) { pages.last }
+
+        it "renders a warning about deleting this page" do
+          assert_select(".govuk-notification-banner", count: 1) do
+            assert_select "*", "Important"
+            assert_select "h3", "Question 3 is at the end of a route"
+            assert_select "p.govuk-body a", "Question 1’s route"
+            assert_select "p.govuk-body", /Question 1’s route\s*goes to this question. If you delete this question, question 1’s routes will also be deleted./
+          end
+        end
+      end
+
+      context "when page to delete is start of a secondary skip route" do
+        let(:pages) do
+          [
+            build(
+              :page,
+              :with_selection_settings,
+              id: 1,
+              form_id: 2,
+              position: 1,
+              question_text: "What is your favourite colour?",
+              selection_options: [{ name: "Red" }, { name: "Green" }, { name: "Blue" }],
+              only_one_option: true,
+              routing_conditions: [
+                build(:condition, routing_page_id: 1, check_page_id: 1, value: "green", goto_page_id: 3),
+              ],
+            ),
+            build(
+              :page,
+              id: 5,
+              form_id: 2,
+              position: 5,
+              routing_conditions: [
+                build(:condition, routing_page_id: 5, check_page_id: 1, value: nil, goto_page_id: 8),
+              ],
+            ),
+          ]
+        end
+
+        let(:page) { pages.last }
+
+        it "renders a warning about deleting this page" do
+          assert_select(".govuk-notification-banner", count: 1) do
+            assert_select "*", "Important"
+            assert_select "h3", "Question 5 is the start of a route"
+            assert_select "p.govuk-body a", "Question 1’s route"
+            assert_select "p.govuk-body", /Question 1’s route\s*starts at this question. If you delete this question, the route from it will also be deleted./
+          end
+        end
+      end
+
+      context "when page to delete is at the end of a secondary skip route" do
+        let(:pages) do
+          [
+            build(
+              :page,
+              :with_selection_settings,
+              id: 1,
+              form_id: 2,
+              position: 1,
+              question_text: "What is your favourite colour?",
+              selection_options: [{ name: "Red" }, { name: "Green" }, { name: "Blue" }],
+              only_one_option: true,
+              routing_conditions: [
+                build(:condition, routing_page_id: 1, check_page_id: 1, value: "green", goto_page_id: 3),
+              ],
+            ),
+            build(
+              :page,
+              id: 5,
+              form_id: 2,
+              position: 5,
+              routing_conditions: [
+                build(:condition, routing_page_id: 5, check_page_id: 1, value: nil, goto_page_id: 8),
+              ],
+            ),
+            build(
+              :page,
+              id: 8,
+              form_id: 2,
+              position: 8,
+            ),
+          ]
+        end
+
+        let(:page) { pages.last }
+
+        it "renders a warning about deleting this page" do
+          assert_select(".govuk-notification-banner", count: 1) do
+            assert_select "*", "Important"
+            assert_select "h3", "Question 8 is at the end of a route"
+            assert_select "p.govuk-body a", "Question 1’s route"
+            assert_select "p.govuk-body", /Question 1’s route\s*goes to this question. If you delete this question, the route to it will also be deleted./
+          end
+        end
+      end
     end
   end