Display breadcrumbs if they are present

A bug was introduced in 8128fb2
so that breadcrumbs were no longer being displayed on the page.
If breadcrumbs are present in the content item, we should display them.
If they're absent, display a back link to the parent manual.

Author: hannako

app/views/content_items/manuals/_manual_section_layout.html.erb

@@ -1,10 +1,17 @@
 <% show_contents ||= false %>
 
 <% content_for :main do %>
-  <%= render "govuk_publishing_components/components/back_link", {
-    text: t("manuals.breadcrumb_contents"),
-    href: @content_item.base_path
-  } %>
+  <% if @content_item.breadcrumbs.any? %>
+    <%= render "govuk_publishing_components/components/breadcrumbs", {
+           border: "bottom",
+           breadcrumbs: @content_item.breadcrumbs,
+           collapse_on_mobile: false } %>
+  <% else %>
+    <%= render "govuk_publishing_components/components/back_link", {
+      text: t("manuals.breadcrumb_contents"),
+      href: @content_item.base_path
+    } %>
+  <% end %>
   <div id="manuals-frontend" class="manuals-frontend-body">
     <% if show_contents %>
       <%= render "govuk_publishing_components/components/contents_list", {

test/integration/hmrc_manual_section_test.rb

@@ -42,12 +42,18 @@ class HmrcManualSectionTest < ActionDispatch::IntegrationTest
     end
   end
 
-  test "renders back link" do
+  test "renders back link if breadcrumbs are not set" do
     setup_and_visit_manual_section
 
     assert page.has_link?(I18n.t("manuals.breadcrumb_contents"), href: "/hmrc-internal-manuals/vat-government-and-public-bodies")
   end
 
+  test "renders breadcrumbs if they are set in the content item" do
+    setup_and_visit_manual_section_with_breadcrumbs
+
+    assert page.has_link?("DMBM510000", href: "/hmrc-internal-manuals/debt-management-and-banking/dmbm510000")
+  end
+
   test "renders section group" do
     setup_and_visit_manual_section
 
@@ -92,4 +98,20 @@ def setup_and_visit_manual_section(content_item = get_content_example("vatgpb200
     stub_content_store_has_item(@content_item["base_path"], @content_item.to_json)
     visit_with_cachebust((@content_item["base_path"]).to_s)
   end
+
+  def setup_and_visit_manual_section_with_breadcrumbs(content_item = get_content_example("vatgpb2000"))
+    @manual = get_content_example_by_schema_and_name("hmrc_manual", "vat-government-public-bodies")
+    @content_item = content_item
+    first_crumb = { "base_path" => "/hmrc-internal-manuals/debt-management-and-banking/dmbm510000", "section_id" => "DMBM510000" }
+    last_crumb = { "base_path" => "/hmrc-internal-manuals/vat-government-public-bodiesg/dmbm510100", "section_id" => "DMBM510100" }
+
+    @content_item["details"]["breadcrumbs"].push(first_crumb, last_crumb)
+    manual_base_path = @content_item["details"]["manual"]["base_path"]
+
+    stub_content_store_has_item(manual_base_path, @manual.to_json)
+
+    stub_content_store_has_item(@content_item["base_path"], @content_item.to_json)
+    stub_content_store_has_item(@content_item["details"]["breadcrumbs"].last["base_path"], @content_item.to_json)
+    visit_with_cachebust((@content_item["base_path"]).to_s)
+  end
 end