fix(a11y): add a title in simple renderer links and autolinks

Closes #8095

app/components/simple_format_component.rb

@@ -28,15 +28,11 @@ class SimpleFormatComponent < ApplicationComponent
       .join("\n\n")   #
     @allow_a = allow_a
     @renderer = Redcarpet::Markdown.new(
-      Redcarpet::BareRenderer.new(link_attributes: external_link_attributes, class_names_map: class_names_map),
+      Redcarpet::BareRenderer.new(class_names_map:),
       REDCARPET_EXTENSIONS.merge(autolink: @allow_a)
     )
   end
 
-  def external_link_attributes
-    { target: '_blank', rel: 'noopener noreferrer' }
-  end
-
   def tags
     if @allow_a
       Rails.configuration.action_view.sanitized_allowed_tags + ['a']
@@ -46,6 +42,6 @@ class SimpleFormatComponent < ApplicationComponent
   end
 
   def attributes
-    ['target', 'rel', 'href', 'class']
+    ['target', 'rel', 'href', 'class', 'title']
   end
 end

app/helpers/application_helper.rb

@@ -142,7 +142,7 @@ module ApplicationHelper
   end
 
   def new_tab_suffix(title)
-    "#{title} — #{I18n.t('utils.new_tab')}"
+    [title, I18n.t('utils.new_tab')].compact.join(' — ')
   end
 
   def download_details(attachment)

app/lib/redcarpet/bare_renderer.rb

@@ -1,6 +1,7 @@
 module Redcarpet
   class BareRenderer < Redcarpet::Render::HTML
     include ActionView::Helpers::TagHelper
+    include ApplicationHelper
 
     # won't use rubocop tag method because it is missing output buffer
     # rubocop:disable Rails/ContentTag
@@ -16,6 +17,17 @@ module Redcarpet
     def paragraph(text)
       content_tag(:p, text, { class: @options[:class_names_map].fetch(:paragraph) {} }, false)
     end
+
+    def link(href, title, content)
+      content_tag(:a, content, { href:, title: new_tab_suffix(title), **external_link_attributes }, false)
+    end
+
+    def autolink(link, link_type)
+      return super unless link_type == :url
+
+      link(link, nil, link)
+    end
+
     # rubocop:enable Rails/ContentTag
   end
 end

spec/components/simple_format_component_spec.rb

@@ -64,6 +64,11 @@ TEXT
     context 'enabled' do
       let(:allow_a) { true }
       it { expect(page).to have_selector("a") }
+      it "inject expected attributes" do
+        link = page.find_link("https://www.demarches-simplifiees.fr").native
+        expect(link[:rel]).to eq("noopener noreferrer")
+        expect(link[:title]).to eq("Nouvel onglet")
+      end
     end
 
     context 'disabled' do