fix: generate multipage TOC with http_prefix

Author: lhokktyn

lib/govuk_tech_docs/table_of_contents/helpers.rb

@@ -19,10 +19,18 @@ def single_page_table_of_contents(html, url: '', max_level: nil)
       end
 
       def multi_page_table_of_contents(resources, current_page, config, current_page_html = nil)
+        # Determine
+        home_url =
+          if config[:http_prefix].end_with?("/")
+            config[:http_prefix]
+          else
+            config[:http_prefix] + "/"
+          end
+
         # Only parse top level html files
         # Sorted by weight frontmatter
         resources = resources
-        .select { |r| r.path.end_with?(".html") && (r.parent.nil? || r.parent.url == "/") }
+        .select { |r| r.path.end_with?(".html") && (r.parent.nil? || r.parent.url == home_url) }
         .sort_by { |r| [r.data.weight ? 0 : 1, r.data.weight || 0] }
 
         render_page_tree(resources, current_page, config, current_page_html)

spec/table_of_contents/helpers_spec.rb

@@ -174,7 +174,7 @@ def add_children(children)
       expect(subject.multi_page_table_of_contents(resources, current_page, config, current_page_html).strip).to eq(expected_multi_page_table_of_contents.strip)
     end
 
-    it 'builds a table of contents from several page resources with a custom http prefix ocnfigured' do
+    it 'builds a table of contents from several page resources with a custom http prefix configured' do
       resources = []
       resources[0] = FakeResource.new('/prefix/index.html', '<h1 id="heading-one">Heading one</h1><h2 id="heading-two">Heading two</h2>', 10, 'Index');
       resources[1] = FakeResource.new('/prefix/a.html', '<h1 id="heading-one">Heading one</h1><h2 id="heading-two">Heading two</h2>', 10, 'Sub page A', resources[0]);