From 0139f71bf27d332c5564de82088e1b6adafce154 Mon Sep 17 00:00:00 2001
From: Jose Farias <jose@37signals.com>
Date: Wed, 18 Dec 2024 16:37:33 -0600
Subject: [PATCH] Use redcarpet as markdown renderer

---
 Gemfile                               |  4 +-
 Gemfile.lock                          | 14 ++----
 config/initializers/markdown.rb       |  2 +-
 lib/markdown_renderer.rb              | 69 ++++++++++++++-------------
 lib/rails_ext/action_text_markdown.rb | 12 ++++-
 5 files changed, 51 insertions(+), 50 deletions(-)

diff --git a/Gemfile b/Gemfile
index c1cc15622..18f89bdc3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,6 @@ gem "propshaft"
 gem "stimulus-rails"
 gem "turbo-rails"
 gem "hotwire_combobox", github: "josefarias/hotwire_combobox", branch: :main
-gem "house_md", bc: "house", branch: :renderer
 
 # Deployment and drivers
 gem "bootsnap", require: false
@@ -21,7 +20,8 @@ gem "thruster", require: false
 # Features
 gem "bcrypt", "~> 3.1.7"
 gem "rqrcode"
-gem "rouge", "~> 4.5"
+gem "redcarpet"
+gem "rouge"
 gem "jbuilder"
 
 # Telemetry
diff --git a/Gemfile.lock b/Gemfile.lock
index 4cfbbd656..0b8769eb0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,12 +1,3 @@
-GIT
-  remote: https://github.com/basecamp/house
-  revision: a8b19e70bbb95a7a0d27e38985a99c2d697a6650
-  branch: renderer
-  specs:
-    house_md (1.0.0)
-      rails
-      zeitwerk
-
 GIT
   remote: https://github.com/josefarias/hotwire_combobox.git
   revision: 57ee6c9087320fab9383a07fa919fe75e0ea72ba
@@ -261,6 +252,7 @@ GEM
       ffi (~> 1.0)
     rdoc (6.8.1)
       psych (>= 4.0.0)
+    redcarpet (3.6.0)
     regexp_parser (2.9.3)
     reline (0.5.12)
       io-console (~> 0.5)
@@ -375,13 +367,13 @@ DEPENDENCIES
   debug
   hotwire-spark
   hotwire_combobox!
-  house_md!
   importmap-rails
   jbuilder
   propshaft
   puma (>= 5.0)
   rails!
-  rouge (~> 4.5)
+  redcarpet
+  rouge
   rqrcode
   rubocop-rails-omakase
   selenium-webdriver
diff --git a/config/initializers/markdown.rb b/config/initializers/markdown.rb
index 2d3a879a3..b5b61401d 100644
--- a/config/initializers/markdown.rb
+++ b/config/initializers/markdown.rb
@@ -1,4 +1,4 @@
 ActiveSupport.on_load :action_text_markdown do
   require "markdown_renderer"
-  ActionText::Markdown.html_renderer = -> { MarkdownRenderer.new }
+  ActionText::Markdown.html_renderer = ->(content) { MarkdownRenderer.build.render(content) }
 end
diff --git a/lib/markdown_renderer.rb b/lib/markdown_renderer.rb
index 9117b28d0..6f466434c 100644
--- a/lib/markdown_renderer.rb
+++ b/lib/markdown_renderer.rb
@@ -1,47 +1,48 @@
 require "rouge/plugins/redcarpet"
 
-class MarkdownRenderer < HouseMd::Renderer
-  class Generator < HouseMd::Generator::Html
-    include Rouge::Plugins::Redcarpet
+class MarkdownRenderer < Redcarpet::Render::HTML
+  include Rouge::Plugins::Redcarpet
 
-    def initialize
-      @id_counts = Hash.new 0
-    end
+  def self.build
+    Redcarpet::Markdown.new MarkdownRenderer.new(filter_html: false),
+      autolink: true, highlight: true, no_intra_emphasis: true,
+      fenced_code_blocks: true, lax_spacing: true, strikethrough: true, tables: true
+  end
 
-    def header(text, header_level)
-      unique_id(text).then do |id|
-        <<~HTML.chomp
-          <h#{header_level} id="#{id}">
-            #{text} <a href="##{id}" class="heading__link" aria-hidden="true">#</a>
-          </h#{header_level}>
-        HTML
-      end
-    end
+  def initialize(...)
+    super
+    @id_counts = Hash.new 0
+  end
 
-    def image(url, alt_text)
+  def header(text, header_level)
+    unique_id(text).then do |id|
       <<~HTML.chomp
-        <a href="#{url}" data-action="lightbox#open:prevent" data-lightbox-target="image" data-lightbox-url-value="#{url}?disposition=attachment">
-          <img src="#{url}" alt="#{alt_text}">
-        </a>
+        <h#{header_level} id="#{id}">
+          #{text} <a href="##{id}" class="heading__link" aria-hidden="true">#</a>
+        </h#{header_level}>
       HTML
     end
+  end
 
-    def code_block(code, language)
-      block_code(code, language) # call Rouge Redcarpet plugin
-    end
+  def image(url, title, alt_text)
+    <<~HTML.chomp
+      <a title="#{title}" href="#{url}" data-action="lightbox#open:prevent" data-lightbox-target="image" data-lightbox-url-value="#{url}?disposition=attachment">
+        <img src="#{url}" alt="#{alt_text}">
+      </a>
+    HTML
+  end
 
-    private
-      attr_reader :id_counts
+  def code_block(code, language)
+    block_code(code, language) # call Rouge Redcarpet plugin
+  end
 
-      def unique_id(text)
-        text.parameterize.then do |base_id|
-          id_counts[base_id] += 1
-          id_counts[base_id] > 1 ? "#{base_id}-#{id_counts[base_id]}" : base_id
-        end
+  private
+    attr_reader :id_counts
+
+    def unique_id(text)
+      text.parameterize.then do |base_id|
+        id_counts[base_id] += 1
+        id_counts[base_id] > 1 ? "#{base_id}-#{id_counts[base_id]}" : base_id
       end
-  end
-
-  def initialize
-    @generator = Generator.new
-  end
+    end
 end
diff --git a/lib/rails_ext/action_text_markdown.rb b/lib/rails_ext/action_text_markdown.rb
index f5d57ece1..65b71fa7f 100644
--- a/lib/rails_ext/action_text_markdown.rb
+++ b/lib/rails_ext/action_text_markdown.rb
@@ -10,11 +10,19 @@ module ActionText
     end
 
     def to_unsafe_html
-      (html_renderer.try(:call) || html_renderer).render(content)
+      if html_renderer.respond_to? :call
+        html_renderer.call content
+      else
+        html_renderer.render content
+      end
     end
 
     def to_plain_text
-      (plain_renderer.try(:call) || plain_renderer).render(content)
+      if plain_renderer.respond_to? :call
+        plain_renderer.call content
+      else
+        plain_renderer.render content
+      end
     end
   end
 end