Build YARD docs from the sass-site repo

This avoids needing to run nested bundler processes, which doesn't
work well on Heroku.

.gitignore

@@ -17,3 +17,4 @@ bundle
 /source/documentation
 Thumbs.db
 .Trashes
+/.yardoc

Gemfile

@@ -24,6 +24,7 @@ group :development do
   gem 'tzinfo-data',            '~> 1.2015.7', platforms: [:mswin, :mingw, :jruby]
   gem 'wdm',                    '~> 0.1.1',    platforms: [:mswin, :mingw]
   gem 'therubyracer',           '~> 0.12.3'
+  gem 'yard',                   '~> 0.9'
 end
 
 gem 'middleman-minify-html',    '~> 3.4.1'

Gemfile.lock

@@ -200,6 +200,7 @@ GEM
       json (>= 1.8.0)
     xpath (2.1.0)
       nokogiri (~> 1.3)
+    yard (0.9.12)
 
 PLATFORMS
   ruby
@@ -227,6 +228,7 @@ DEPENDENCIES
   typogruby (~> 1.0.18)
   tzinfo-data (~> 1.2015.7)
   wdm (~> 0.1.1)
+  yard (~> 0.9)
 
 RUBY VERSION
    ruby 2.4.1p111

Rakefile

@@ -1,14 +1,8 @@
+require 'yard'
 
-# This is a helper function that properly sets up
-# the environment in the .sass folder for bundle commands to work
-def bundle(cmd)
-  Bundler.with_clean_env do
-    sh %{bundle #{cmd}}
-  end
-end
-
-
-task :sass do
+namespace :sass do
+  # Check out the latest stable version of Ruby Sass into the .sass directory.
+  task :checkout do
     unless Dir.exists?(".sass")
       sh %{git clone git://github.com/sass/sass .sass}
     end
@@ -22,31 +16,78 @@ task :sass do
         # Check out the most recent released stable version
         sh %{git checkout #{File.read("VERSION").strip}}
       end
-
-    bundle %{install}
     end
-end
+  end
 
-task :sass_version => :sass do
+  task :version => :checkout do
     require 'yaml'
     version = File.read(".sass/VERSION").strip
     name = File.read(".sass/VERSION_NAME").strip
     File.open('data/version.yml', 'w') {|f| f.write(YAML.dump({'number' => version, 'name' => name}))}
-end
+  end
 
-task :sass_docs => :sass do
-  ENV["RUBOCOP"] = "false"
-  Dir.chdir(".sass") { bundle %{exec rake doc}}
+  YARD::Rake::YardocTask.new(:doc) do |t|
+    t.before = lambda do
+      t.files = FileList.new('.sass/lib/**/*.rb') do |list|
+        list.exclude('.sass/lib/sass/plugin/merb.rb')
+        list.exclude('.sass/lib/sass/plugin/rails.rb')
+      end.to_a
+      t.options += FileList.new('.sass/yard/*.rb').to_a.map {|f| ['-e', f]}.flatten
+      files = FileList.new('.sass/doc-src/*').to_a.sort_by {|s| s.size} + %w[.sass/MIT-LICENSE .sass/VERSION]
+      t.options << '--files' << files.join(',')
+      t.options << '--main' << '.sass/README.md'
+    end
+
+    t.after = lambda do
       sh %{rm -rf source/documentation}
-  sh %{cp -r .sass/doc source/documentation}
+      sh %{mv doc source/documentation}
       Dir['source/documentation/**/*.html'].each do |path|
         contents = File.read(path)
         File.open(path, 'w') {|file| file.write(contents.gsub(%r{css/common\.css}, '../assets/css/docs.css'))}
       end
-end
 
-desc "Import information from Sass."
-task :import_sass => [:sass_version, :sass_docs]
+      require 'nokogiri'
+      doc = Nokogiri::HTML(File.read('source/documentation/file.SASS_REFERENCE.html'))
+
+      doc.css("#filecontents").css("h1, h2, h3, h4, h5, h6").each do |h|
+        next if h.inner_text.empty?
+        h['id'] =
+          case h.inner_text
+          when "Referencing Parent Selectors: &"; "parent-selector"
+          when /^Comments:/; "comments"
+          when "Strings"; "sass-script-strings"
+          when "Division and /"; "division-and-slash"
+          when /^Subtraction,/; "subtraction"
+          when "& in SassScript"; "parent-script"
+          when "@-Rules and Directives"; "directives"
+          when "@extend-Only Selectors"; "placeholders"
+          when "@extend-Only Selectors"; "placeholders"
+          when "@each"; "each-directive"
+          when "Multiple Assignment"; "each-multi-assign"
+          when "Mixin Directives"; "mixins"
+          when /^Defining a Mixin:/; "defining_a_mixin"
+          when /^Including a Mixin:/; "including_a_mixin"
+          when "Arguments"; "mixin-arguments"
+          when "Passing Content Blocks to a Mixin"; "mixin-content"
+          else
+            h.inner_text.downcase.gsub(/[^a-z _-]/, '').gsub(' ', '_')
+          end
+      end
+
+      # Give each option an anchor.
+      doc.css("#filecontents li p strong code").each do |c|
+        c['id'] = c.inner_text.gsub(/:/, '') + '-option'
+      end
+
+      File.write('source/documentation/file.SASS_REFERENCE.html', doc.to_html)
+    end
+  end
+  Rake::Task['sass:doc'].prerequisites.insert(0, 'sass:checkout')
+  Rake::Task['sass:doc'].instance_variable_set('@comment', nil)
+
+  desc "Import information from Sass."
+  task :import => [:doc, :version]
+end
 
 desc "Build the middleman-controlled portion of the site."
 task :middleman do
@@ -54,7 +95,7 @@ task :middleman do
 end
 
 desc "Build the site."
-task :build => [:import_sass, :middleman]
+task :build => ["sass:import", :middleman]
 
 task :check_ready_to_deploy do
   if `git config remote.heroku.url`.strip != "git@heroku.com:sass-lang.git"