amelioration(a11y): extrait un nouveau composant pour rendre du texte saisi par un humain accessible

Gemfile

@@ -70,6 +70,7 @@ gem 'rack-attack'
 gem 'rails'
 gem 'rails-i18n' # Locales par défaut
 gem 'rake-progressbar', require: false
+gem 'redcarpet'
 gem 'rexml' # add missing gem due to ruby3 (https://github.com/Shopify/bootsnap/issues/325)
 gem 'rgeo-geojson'
 gem 'rqrcode'

Gemfile.lock

@@ -573,6 +573,7 @@ GEM
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
+    redcarpet (3.6.0)
     regexp_parser (2.6.0)
     request_store (1.5.0)
       rack (>= 1.4)
@@ -909,6 +910,7 @@ DEPENDENCIES
   rails-erd
   rails-i18n
   rake-progressbar
+  redcarpet
   rexml
   rgeo-geojson
   rqrcode

app/components/simple_format_component.rb

@@ -0,0 +1,51 @@
+class SimpleFormatComponent < ApplicationComponent
+  # see: https://github.com/vmg/redcarpet#and-its-like-really-simple-to-use
+  REDCARPET_EXTENSIONS = {
+    no_intra_emphasis: false,
+    tables: false,
+    fenced_code_blocks: false,
+    autolink: false,
+    disable_indented_code_blocks: false,
+    strikethrough: false,
+    lax_spacing: false,
+    space_after_headers: false,
+    superscript: false,
+    underline: false,
+    highlight: false,
+    quote: false,
+    footnotes: false
+  }
+
+  # see: https://github.com/vmg/redcarpet#darling-i-packed-you-a-couple-renderers-for-lunch
+  REDCARPET_RENDERER_OPTS = {
+    no_images: true
+  }
+
+  def initialize(text, allow_a: true, class_names_map: {})
+    @text = (text || "").gsub(/\R/, "\n\n") # force double \n otherwise a single one won't split paragraph
+      .split("\n\n")  #
+      .map(&:lstrip)  # this block prevent redcarpet to consider "   text" as block code by lstriping
+      .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_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']
+    else
+      Rails.configuration.action_view.sanitized_allowed_tags
+    end
+  end
+
+  def attributes
+    ['target', 'rel', 'href', 'class']
+  end
+end

app/components/simple_format_component/simple_format_component.html.haml

@@ -0,0 +1 @@
+= sanitize(@renderer.render(@text), tags:, attributes:)

app/lib/redcarpet/bare_renderer.rb

@@ -0,0 +1,21 @@
+module Redcarpet
+  class BareRenderer < Redcarpet::Render::HTML
+    include ActionView::Helpers::TagHelper
+
+    # won't use rubocop tag method because it is missing output buffer
+    # rubocop:disable Rails/ContentTag
+    def list(content, list_type)
+      tag = list_type == :ordered ? :ol : :ul
+      content_tag(tag, content, { class: @options[:class_names_map].fetch(:list) {} }, false)
+    end
+
+    def list_item(content, list_type)
+      content_tag(:li, content.strip.gsub(/<\/?p>/, ''), {}, false)
+    end
+
+    def paragraph(text)
+      content_tag(:p, text, { class: @options[:class_names_map].fetch(:paragraph) {} }, false)
+    end
+    # rubocop:enable Rails/ContentTag
+  end
+end

spec/components/simple_format_component_spec.rb

@@ -0,0 +1,73 @@
+describe SimpleFormatComponent, type: :component do
+  let(:allow_a) { false }
+  before { render_inline(described_class.new(text, allow_a: allow_a)) }
+
+  context 'one line' do
+    let(:text) do
+      "1er paragraphe"
+    end
+    it { expect(page).to have_selector("p", count: 1, text: text) }
+  end
+
+  context 'one with leading spaces' do
+    let(:text) do
+      <<-TEXT
+      1er paragraphe
+TEXT
+    end
+    it { expect(page).to have_selector("p", count: 1, text: text.strip) }
+  end
+
+  context 'two lines' do
+    let(:text) do
+      <<~TEXT
+        1er paragraphe
+        2eme paragraphe
+      TEXT
+    end
+
+    it { expect(page).to have_selector("p", count: 2) }
+    it { text.split("\n").map(&:strip).map { expect(page).to have_text(_1) } }
+  end
+
+  context 'unordered list items' do
+    let(:text) do
+      <<~TEXT
+        - 1er paragraphe
+        - paragraphe
+      TEXT
+    end
+
+    it { expect(page).to have_selector("ul", count: 1) }
+    it { expect(page).to have_selector("li", count: 2) }
+  end
+
+  context 'ordered list items' do
+    let(:text) do
+      <<~TEXT
+        1. 1er paragraphe
+        2. paragraphe
+      TEXT
+    end
+
+    it { expect(page).to have_selector("ol", count: 1) }
+    it { expect(page).to have_selector("li", count: 2) }
+  end
+
+  context 'auto-link' do
+    let(:text) do
+      <<~TEXT
+        bonjour https://www.demarches-simplifiees.fr
+      TEXT
+    end
+
+    context 'enabled' do
+      let(:allow_a) { true }
+      it { expect(page).to have_selector("a") }
+    end
+
+    context 'disabled' do
+      it { expect(page).not_to have_selector("a") }
+    end
+  end
+end