Really naive CHANGELOG parser we used on Code School for a while to export public-facing release notes from a private-ish CHANGELOG.md file.

changelog_parser.rb

require 'vandamme'

module PagesHelper
  def changes
    changes = {}

    sections = changelog_file.each_with_index do |day, index|
      change_sets = {}

      day[1].scan(section_title_scanner) do |match|
        section_title = "#{match.first}"
        section_content = $~.post_match.strip # removing new lines
        puts "section title: #{section_title}"
        changelog_scanner = StringScanner.new(section_content)

        changelog_scanner.scan_until(section_title_scanner)

        # on the last iteration, there will be no pre_match because there is no
        # next section to scan_until, in that case simply return the fulll
        # section_content as it only contains a list of items.
        content = (changelog_scanner.pre_match || section_content).split(/- /).reject do |a|
          # filter out stuff marked as [INTERNAL] unless an internal query param is found
          # I know, super secure, right?
          if a.include?('[INTERNAL]') && !params[:internal]
            true
          elsif a.empty?
            true
          end
        end

        change_sets.merge!({ "#{section_title}" => content }) unless content.empty?
      end

      changes.merge!({ "#{day.first}" => change_sets }) unless change_sets.empty?
    end

    @changes ||= changes
  end

  private

  def section_title_scanner
    Regexp.new('#{3} (.*)') # section separators ("### Added", "### Fixed")
  end

  def changelog_file
    @changelog ||= begin
      log = File.open('CHANGELOG.md').read
      parser = Vandamme::Parser.new(changelog: log, version_header_exp: '#{2} (\d{4}-\d{2}-\d{2})', format: 'markdown')
      days = parser.parse
    end
  end
end

view.html.haml

- changes.each do |set|
  %article.content-section
    %h2.mbm= time_tag Date.parse(set.first), Date.parse(set.first).to_formatted_s(:long)
    - if !set.last.empty?
      - set.last.each do |section|
        .content-section
          %h3.h4= section.first
          %ul.list.list--styled
            - section.last.each do |item|
              %li.list-item
                :markdown
                  #{item}