A https://github.com/cdchapman/rubypants-unicode filter for https://github.com/jch/html-pipeline.

html_pipeline_rubypants.rb

# Add the following to your Gemfile
# gem 'rubypants-unicode',  '~>0.2.3',  require: false

begin
  require 'rubypants-unicode'
rescue LoadError => _
  abort "Missing dependency 'rubypants-unicode' for RubyPantsFilter."
end

module HTML
  class Pipeline
    class RubyPantsFilter < TextFilter
      def call
        RubyPants.new(@text).to_html
      end
    end
  end
end