Add 'built by' statement to footer

We have this in the product page repo so it makes sense to copy it here
for consistency too.

Author: DavidBiddle

app/views/layouts/application.html.erb

@@ -21,8 +21,18 @@
 <% end %>
 
 <% content_for :footer do %>
-  <% meta_links = {t("footer.accessibility_statement") => "https://www.forms.service.gov.uk/accessibility", t("footer.cookies") => "https://www.forms.service.gov.uk/cookies", t("footer.privacy") => "https://www.forms.service.gov.uk/privacy", t("footer.terms_of_use") => "https://www.forms.service.gov.uk/terms-of-use"} %>
-  <%= govuk_footer meta_items_title: t("footer.helpful_links"), meta_items: meta_links %>
+  <% meta_items = {t("footer.accessibility_statement") => "https://www.forms.service.gov.uk/accessibility", t("footer.cookies") => "https://www.forms.service.gov.uk/cookies", t("footer.privacy") => "https://www.forms.service.gov.uk/privacy", t("footer.terms_of_use") => "https://www.forms.service.gov.uk/terms-of-use"} %>
+
+  <%= govuk_footer meta_items_title: t("footer.helpful_links"), meta_items: do |footer| %>
+    <%= footer.with_meta_html do %>
+      <div class="govuk-footer__meta-custom">
+        <%= t("footer.built_by_statement_html",
+              link: link_to(t("footer.built_by_link"),
+                            "https://www.gov.uk/government/organisations/government-digital-service",
+                            class: ["govuk-footer__link"])) %>
+      </div>
+    <% end %>
+  <% end %>
 <% end %>
 
 <%= render template: "layouts/base" %>

config/locales/en.yml

@@ -310,6 +310,8 @@ en:
     no_content_added_html: "<p>No content added</p>"
   footer:
     accessibility_statement: Accessibility statement
+    built_by_link: Government Digital Service
+    built_by_statement_html: Built by the %{link}
     cookies: Cookies
     helpful_links: Helpful links
     privacy: Privacy

spec/requests/application_controller_spec.rb

@@ -232,13 +232,22 @@
   end
 
   describe "footer" do
-    it "contains links related to the service" do
+    before do
       get root_path
+    end
 
+    it "contains links related to the service" do
       expect(response.body).to include('<a class="govuk-footer__link" href="https://www.forms.service.gov.uk/accessibility">Accessibility statement</a>')
       expect(response.body).to include('<a class="govuk-footer__link" href="https://www.forms.service.gov.uk/cookies">Cookies</a>')
       expect(response.body).to include('<a class="govuk-footer__link" href="https://www.forms.service.gov.uk/privacy">Privacy</a>')
       expect(response.body).to include('<a class="govuk-footer__link" href="https://www.forms.service.gov.uk/terms-of-use">Terms of use</a>')
     end
+
+    it "contains the 'built by' statement" do
+      page = Capybara::Node::Simple.new(response.body)
+
+      expect(page).to have_text("Built by the")
+      expect(page).to have_link("Government Digital Service", href: "https://www.gov.uk/government/organisations/government-digital-service")
+    end
   end
 end