Popular links delete

app/controllers/homepage_controller.rb

@@ -45,8 +45,38 @@ def publish
     redirect_to show_popular_links_path
   end
 
+  def destroy
+    if @latest_popular_links.can_delete?
+      @latest_popular_links.delete ? flash[:success] = "Popular links draft deleted.".html_safe : flash[:danger] = application_error_message
+    else
+      flash[:danger] = cannot_delete_published_error_message
+    end
+  rescue StandardError => e
+    Rails.logger.error "Error #{e.class} #{e.message}"
+    flash[:danger] = application_error_message
+  ensure
+    redirect_to show_popular_links_path
+  end
+
+  def confirm_destroy
+    if @latest_popular_links.can_delete?
+      render "homepage/popular_links/confirm_destroy"
+    else
+      flash[:danger] = cannot_delete_published_error_message
+      redirect_to show_popular_links_path
+    end
+  end
+
 private
 
+  def cannot_delete_published_error_message
+    "Can't delete an already published edition. Please create a new edition to make changes.".html_safe
+  end
+
+  def application_error_message
+    "Due to an application error, the draft couldn't be deleted.".html_safe
+  end
+
   def rescue_already_published_error(error)
     already_published_error?(JSON.parse(error.http_body)) ? "Popular links publish was unsuccessful, cannot publish an already published content item.".html_safe : publishing_api_publish_error_message
   end

app/models/popular_links_edition.rb

@@ -59,4 +59,8 @@ def update_type
   def locale
     "en".freeze
   end
+
+  def can_delete?
+    state == "draft"
+  end
 end

app/views/homepage/popular_links/_sidebar.html.erb

@@ -16,8 +16,9 @@
       items: [
         primary_link_button_for(edit_popular_links_path(@latest_popular_links), "Edit popular links") ,
         secondary_button_for(@latest_popular_links, publish_popular_links_path(@latest_popular_links), "Publish"),
-        link_to("Preview (opens in new tab)", preview_homepage_path(@latest_popular_links), rel:"noreferrer noopener", target:"_blank", class: "govuk-link")
-      ]
+        link_to("Preview (opens in new tab)", preview_homepage_path(@latest_popular_links), rel:"noreferrer noopener", target:"_blank", class: "govuk-link"),
+        link_to("Delete draft", confirm_destroy_popular_links_path(@latest_popular_links), class: "govuk-link gem-link--destructive")
+        ]
     } %>
   <% end %>
-</div>
+</div>

app/views/homepage/popular_links/confirm_destroy.html.erb

@@ -0,0 +1,16 @@
+<% content_for :context, @latest_popular_links.title %>
+<% content_for :page_title, "Delete draft" %>
+<% content_for :title, "Delete draft" %>
+
+<div class="govuk-grid-column-two-thirds">
+  <%= form_tag delete_popular_links_path(@latest_popular_links), method: :delete do %>
+    <p class="govuk-body govuk-!-margin-bottom-7">Are you sure you want to delete this draft?</p>
+    <div class="govuk-button-group govuk-!-margin-bottom-6">
+      <%= render "govuk_publishing_components/components/button", {
+        text: "Delete",
+        destructive: true,
+      } %>
+      <%= link_to("Cancel", show_popular_links_path, class: "govuk-link govuk-link--no-visited-state") %>
+    </div>
+  <% end %>
+</div>

config/routes.rb

@@ -82,6 +82,9 @@
   patch "/homepage/popular-links/:id" => "homepage#update", as: "update_popular_links"
   post "/homepage/popular-links/:id/publish" => "homepage#publish", as: "publish_popular_links"
 
+  delete "/homepage/popular-links/:id" => "homepage#destroy", as: "delete_popular_links"
+  get "homepage/popular-links/:id/confirm-destroy" => "homepage#confirm_destroy", as: "confirm_destroy_popular_links"
+
   mount GovukAdminTemplate::Engine, at: "/style-guide"
   mount Flipflop::Engine => "/flipflop"
   mount GovukPublishingComponents::Engine, at: "/component-guide"

test/functional/homepage_controller_test.rb

@@ -254,6 +254,86 @@ class HomepageControllerTest < ActionController::TestCase
     end
   end
 
+  context "#confirm_destroy" do
+    should "render confirm destroy page for draft edition" do
+      popular_links = FactoryBot.create(:popular_links, state: "draft")
+
+      get :confirm_destroy, params: { id: popular_links.id }
+
+      assert_template "homepage/popular_links/confirm_destroy"
+    end
+
+    should "redirect with error message if edition is published" do
+      popular_links = FactoryBot.create(:popular_links, state: "published")
+
+      get :confirm_destroy, params: { id: popular_links.id }
+
+      assert_redirected_to show_popular_links_path
+      assert_equal "Can't delete an already published edition. Please create a new edition to make changes.", flash[:danger]
+    end
+  end
+
+  context "#destroy" do
+    context "edition is draft" do
+      setup do
+        @popular_links = FactoryBot.create(:popular_links, state: "draft")
+        get :confirm_destroy, params: { id: @popular_links.id }
+      end
+
+      should "delete the popular links from the database and display success message" do
+        assert_equal 1, PopularLinksEdition.count
+
+        delete :destroy, params: { id: @popular_links.id }
+
+        assert_equal 0, PopularLinksEdition.count
+        assert_equal "Popular links draft deleted.", flash[:success]
+      end
+
+      should "redirect to show path on success" do
+        delete :destroy, params: { id: @popular_links.id }
+
+        assert_redirected_to show_popular_links_path
+      end
+
+      should "redirect to show page with 'application error' if delete edition returns false" do
+        PopularLinksEdition.any_instance.stubs(:delete).returns(false)
+
+        delete :destroy, params: { id: @popular_links.id }
+
+        assert_equal "Due to an application error, the draft couldn't be deleted.", flash[:danger]
+        assert_redirected_to show_popular_links_path
+      end
+    end
+
+    context "edition is published" do
+      setup do
+        @popular_links = FactoryBot.create(:popular_links, state: "published", version_number: "2")
+      end
+
+      should "show 'cant delete published edition' when trying to delete a published edition" do
+        delete :destroy, params: { id: @popular_links.id }
+
+        assert_equal "Can't delete an already published edition. Please create a new edition to make changes.", flash[:danger]
+        assert_redirected_to show_popular_links_path
+      end
+    end
+
+    context "database errors" do
+      setup do
+        @popular_links = FactoryBot.create(:popular_links, state: "draft")
+      end
+
+      should "redirect to show page and alert 'application error'" do
+        PopularLinksEdition.any_instance.stubs(:delete).raises(Mongoid::Errors::MongoidError.new)
+
+        delete :destroy, params: { id: @popular_links.id }
+
+        assert_equal "Due to an application error, the draft couldn't be deleted.", flash[:danger]
+        assert_redirected_to show_popular_links_path
+      end
+    end
+  end
+
 private
 
   def stub_publishing_api_publish_already_published_error

test/integration/homepage_popular_links_test.rb

@@ -69,6 +69,12 @@ class HomepagePopularLinksTest < JavascriptIntegrationTest
       assert page.has_link?("Preview (opens in new tab)", href: /#{Plek.external_url_for('draft-origin')}/)
     end
 
+    should "have 'delete draft' link navigating to 'confirm destroy' page" do
+      click_button("Create new edition")
+
+      assert page.has_link?("Delete draft", href: /confirm-destroy/)
+    end
+
     should "create a new record with next version and 'draft' status" do
       row = find_all(".govuk-summary-list__row")
       assert row[0].has_text?("Edition")
@@ -158,6 +164,47 @@ class HomepagePopularLinksTest < JavascriptIntegrationTest
     end
   end
 
+  context "#confirm_destroy" do
+    setup do
+      click_button("Create new edition")
+    end
+
+    should "show the 'Delete draft' confirmation page" do
+      click_link("Delete draft")
+
+      assert page.has_text?("Delete draft")
+      assert page.has_text?("Are you sure you want to delete this draft?")
+    end
+
+    should "navigate to show page when 'Cancel' button is clicked" do
+      click_link("Delete draft")
+      click_link("Cancel")
+
+      assert_title "Popular on GOV.UK"
+    end
+  end
+
+  context "#destroy" do
+    setup do
+      click_button("Create new edition")
+    end
+
+    should "show the previously published edition when a draft is deleted" do
+      row = find_all(".govuk-summary-list__row")
+      assert row[0].has_text?("Edition")
+      assert row[0].has_text?("2")
+      assert row[1].has_text?("Draft")
+
+      click_link("Delete draft")
+      click_button("Delete")
+
+      row = find_all(".govuk-summary-list__row")
+      assert row[0].has_text?("Edition")
+      assert row[0].has_text?("1")
+      assert row[1].has_text?("Published")
+    end
+  end
+
   def visit_popular_links
     visit "/homepage/popular-links"
   end