Replace Redcarpet by CommonMarker

Gemfile

@@ -11,6 +11,7 @@ gem 'actionpack-page_caching'
 gem 'active_link_to'
 gem 'bootstrap', '~> 5.3.2'
 gem 'carrierwave', '~> 3.0'
+gem 'commonmarker', '~>1.0.0.pre11'
 gem 'draper'
 gem 'friendly_id', '~> 5.5'
 gem 'globalize'
@@ -27,7 +28,6 @@ gem 'oj' # Fast JSON parser and object serializer
 gem 'pg' # Ruby interface to PostgreSQL RDBMS
 gem 'puma' # Ruby web server built for concurrency
 gem 'rails-i18n'
-gem 'redcarpet'
 gem 'route_translator' # Manage translations of routes
 gem 'sass-rails', '~> 6.0'
 gem 'simple_form', '~> 5.3'

Gemfile.lock

@@ -160,6 +160,7 @@ GEM
       descendants_tracker (~> 0.0.1)
     colored (1.2)
     colorize (0.8.1)
+    commonmarker (1.0.0.pre11-x86_64-linux)
     concurrent-ruby (1.2.2)
     connection_pool (2.4.1)
     crass (1.0.6)
@@ -281,7 +282,7 @@ GEM
     language_server-protocol (3.17.0.3)
     launchy (2.5.2)
       addressable (~> 2.8)
-    libv8-node (18.16.0.0)
+    libv8-node (18.16.0.0-x86_64-linux)
     listen (3.8.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
@@ -310,7 +311,6 @@ GEM
     mini_histogram (0.3.1)
     mini_magick (4.12.0)
     mini_mime (1.1.5)
-    mini_portile2 (2.8.5)
     mini_racer (0.8.0)
       libv8-node (~> 18.16.0.0)
     minitest (5.20.0)
@@ -329,8 +329,7 @@ GEM
       net-protocol
     net-ssh (7.2.0)
     nio4r (2.5.9)
-    nokogiri (1.15.4)
-      mini_portile2 (~> 2.8.2)
+    nokogiri (1.15.4-x86_64-linux)
       racc (~> 1.4)
     normalize-rails (8.0.1)
     oj (3.16.1)
@@ -579,6 +578,7 @@ GEM
 
 PLATFORMS
   ruby
+  x86_64-linux
 
 DEPENDENCIES
   actionpack-action_caching
@@ -596,6 +596,7 @@ DEPENDENCIES
   capybara
   carrierwave (~> 3.0)
   colored
+  commonmarker (~> 1.0.0.pre11)
   cuprite
   database_cleaner (~> 2.0.1)
   derailed_benchmarks
@@ -627,7 +628,6 @@ DEPENDENCIES
   rails-controller-testing
   rails-i18n
   rails_best_practices
-  redcarpet
   reek
   route_translator
   rspec-rails (~> 6.0.3)

config/initializers/markdown.rb

@@ -1,40 +1,6 @@
-require 'redcarpet'
-
-module ActionView
-  module Template::Handlers
-    # Rails template handler for Markdown
-    class Markdown
-      class_attribute :default_format
-      self.default_format = Mime[:html]
-
-      # @param template [ActionView::Template]
-      # @return [String] Ruby code that when evaluated will return the rendered
-      #   content
-      def call(_template, body)
-        @markdown ||= Redcarpet::Markdown.new(renderer, params)
-        "#{@markdown.render(body).inspect}.html_safe"
-      end
-
-      private
-
-      def params
-        {
-          autolink: true, fenced_code_blocks: true,
-          space_after_headers: true, tables: true
-        }
-      end
-
-      def renderer
-        options = {
-          link_attributes: { rel: 'nofollow' }
-        }
-        Redcarpet::Render::HTML.new(options)
-      end
-    end
-  end
-end
+require 'handlers/markdown_handler'
 
 ActionView::Template.register_template_handler(
   :md,
-  ActionView::Template::Handlers::Markdown.new
+  Handlers::MarkdownHandler.new
 )

lib/handlers/markdown_handler.rb

@@ -0,0 +1,12 @@
+require 'markdown'
+
+module Handlers
+  class MarkdownHandler
+    class_attribute :default_format
+    self.default_format = Mime[:html]
+
+    def call(_template, body)
+      Markdown.new(body).to_html.inspect
+    end
+  end
+end

lib/markdown.rb

@@ -0,0 +1,25 @@
+require 'commonmarker'
+
+class Markdown
+  RENDER = {
+    hardbreaks: false
+  }.freeze
+
+  def initialize(input)
+    @input = input
+  end
+
+  def to_html
+    Commonmarker.to_html(input, options:)
+  end
+
+  private
+
+  attr_reader :input
+
+  def options
+    {
+      render: RENDER
+    }
+  end
+end

spec/lib/markdown_spec.rb

@@ -0,0 +1,214 @@
+require 'spec_helper'
+require 'markdown'
+
+RSpec.describe Markdown do
+  describe '#to_html' do
+    it 'returns the HTML code that corresponds to the important text in Markdown' do
+      important_text_in_markdown = '**Hello** world'
+      expected_result_in_html = "<p><strong>Hello</strong> world</p>\n"
+      markdown = described_class.new(important_text_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the emphasized text in Markdown' do
+      emphasized_text_in_markdown = 'Hello *world*'
+      expected_result_in_html = "<p>Hello <em>world</em></p>\n"
+      markdown = described_class.new(emphasized_text_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the striked text in Markdown' do
+      strikethrough_in_markdown = 'Hello ~~World~~'
+      expected_result_in_html = "<p>Hello <del>World</del></p>\n"
+      markdown = described_class.new(strikethrough_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code the corresponds to the text containing quotation marks in Markdown' do
+      input = "My name is 'Bond, James Bond'"
+      expected_result_in_html = "<p>My name is 'Bond, James Bond'</p>\n"
+      markdown = described_class.new(input)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the inline code in Markdown' do
+      inline_code_in_markdown = 'This is `inline code`'
+      expected_result_in_html = "<p>This is <code>inline code</code></p>\n"
+      markdown = described_class.new(inline_code_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the block code in Markdown' do
+      block_code_in_markdown = <<~BLOCK_CODE
+        ```ruby
+        puts 'Hello world'
+        ```
+      BLOCK_CODE
+      expected_result_in_html = '<pre style="background-color:#2b303b;">' \
+                                '<code class="language-ruby">' \
+                                '<span style="color:#96b5b4;">puts </span>' \
+                                '<span style="color:#c0c5ce;">&#39;</span>' \
+                                '<span style="color:#a3be8c;">Hello world</span>' \
+                                "<span style=\"color:#c0c5ce;\">&#39;\n</span></code></pre>\n"
+      markdown = described_class.new(block_code_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the header in Markdown' do
+      header_in_markdown = '# The most important heading'
+      expected_result_in_html = '<h1><a href="#the-most-important-heading" ' \
+                                'aria-hidden="true" class="anchor" id="the-most-important-heading"></a>' \
+                                "The most important heading</h1>\n"
+      markdown = described_class.new(header_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the link in Markdown' do
+      link_in_markdown = 'This is the [FractalSoft](https://fractalsoft.org/)'
+      expected_result_in_html = <<~HTML
+        <p>This is the <a href="https://fractalsoft.org/">FractalSoft</a></p>
+      HTML
+      markdown = described_class.new(link_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the link in Markdown with www recognition' do
+      markdown_with_www_link = 'Visit www.fractalsoft.org'
+      expected_result_in_html = <<~HTML
+        <p>Visit <a href="http://www.fractalsoft.org">www.fractalsoft.org</a></p>
+      HTML
+      markdown = described_class.new(markdown_with_www_link)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the image as link in Markdown' do
+      image_as_link_in_markdown = '[![My image](/path/to/image)](https://fractalsoft.org/)'
+      expected_result_in_html = <<~HTML
+        <p><a href="https://fractalsoft.org/"><img src="/path/to/image" alt="My image" /></a></p>
+      HTML
+      markdown = described_class.new(image_as_link_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the link in header in Markdown' do
+      header_link_in_markdown = '# My Header [link](https://fractalsoft.org/)'
+      expected_result_in_html = '<h1><a href="#my-header-link" aria-hidden="true" class="anchor" id="my-header-link"></a>' \
+                                "My Header <a href=\"https://fractalsoft.org/\">link</a></h1>\n"
+      markdown = described_class.new(header_link_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the quote in Markdown' do
+      quote_in_markdown = '> Be or not to be'
+      expected_result_in_html = "<blockquote>\n<p>Be or not to be</p>\n</blockquote>\n"
+      markdown = described_class.new(quote_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the ordered list in Markdown' do
+      ordered_list_in_markdown = <<~ORDERED_LIST
+        1. First item
+        2. Second item
+        3. Third item
+      ORDERED_LIST
+      expected_result_in_html = <<~HTML
+        <ol>
+        <li>First item</li>
+        <li>Second item</li>
+        <li>Third item</li>
+        </ol>
+      HTML
+      markdown = described_class.new(ordered_list_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the unordered list in Markdown' do
+      unordered_list_in_markdown = <<~UNORDERED_LIST
+        - First item
+        - Second item
+        - Third item
+      UNORDERED_LIST
+      expected_result_in_html = <<~HTML
+        <ul>
+        <li>First item</li>
+        <li>Second item</li>
+        <li>Third item</li>
+        </ul>
+      HTML
+      markdown = described_class.new(unordered_list_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the image in Markdown' do
+      image_in_markdown = '![My image](/path/to/image)'
+      expected_result_in_html = <<~HTML
+        <p><img src="/path/to/image" alt="My image" /></p>
+      HTML
+      markdown = described_class.new(image_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the table in Markdown' do
+      table_in_markdown = <<~TABLE
+        | Syntax      | Description |
+        |-------------|-------------|
+        | Header      | Title       |
+        | Paragraph   | Text        |
+      TABLE
+      expected_result_in_html = <<~HTML
+        <table>
+        <thead>
+        <tr>
+        <th>Syntax</th>
+        <th>Description</th>
+        </tr>
+        </thead>
+        <tbody>
+        <tr>
+        <td>Header</td>
+        <td>Title</td>
+        </tr>
+        <tr>
+        <td>Paragraph</td>
+        <td>Text</td>
+        </tr>
+        </tbody>
+        </table>
+      HTML
+      markdown = described_class.new(table_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+
+    it 'returns the HTML code that corresponds to the task list in Markdown' do
+      task_list_in_markdown = <<~TASK_LIST
+        - [ ] first to do
+        - [x] second to do
+      TASK_LIST
+      expected_result_in_html = <<~HTML
+        <ul>
+        <li><input type="checkbox" disabled="" /> first to do</li>
+        <li><input type="checkbox" checked="" disabled="" /> second to do</li>
+        </ul>
+      HTML
+      markdown = described_class.new(task_list_in_markdown)
+
+      expect(markdown.to_html).to eq(expected_result_in_html)
+    end
+  end
+end