Add support for the case that RDoc is installed as a default gem

lib/rdoc/rubygems_hook.rb

@@ -1,17 +1,300 @@
+# frozen_string_literal: true
+
+require 'rubygems/user_interaction'
+require 'fileutils'
+
+require_relative '../rdoc'
+
+# We define the following two similar name classes in this file:
 #
+# - RDoc::RubyGemsHook
+# - RDoc::RubygemsHook
+#
+# RDoc::RubyGemsHook is the main class that has real logic.
+#
+# RDoc::RubygemsHook is a class that is only for
+# compatibility. RDoc::RubygemsHook is used by RubyGems directly. We
+# can remove this when all maintained RubyGems remove
+# `rubygems/rdoc.rb`.
+
+class RDoc::RubyGemsHook
+
+  include Gem::UserInteraction
+  extend  Gem::UserInteraction
+
+  @rdoc_version = nil
+  @specs = []
+
+  ##
+  # Force installation of documentation?
+
+  attr_accessor :force
+
+  ##
+  # Generate rdoc?
+
+  attr_accessor :generate_rdoc
+
+  ##
+  # Generate ri data?
+
+  attr_accessor :generate_ri
+
+  class << self
+
+    ##
+    # Loaded version of RDoc.  Set by ::load_rdoc
+
+    attr_reader :rdoc_version
+
+  end
+
+  ##
+  # Post installs hook that generates documentation for each specification in
+  # +specs+
+
+  def self.generate installer, specs
+    start = Time.now
+    types = installer.document
+
+    generate_rdoc = types.include? 'rdoc'
+    generate_ri   = types.include? 'ri'
+
+    specs.each do |spec|
+      new(spec, generate_rdoc, generate_ri).generate
+    end
+
+    return unless generate_rdoc or generate_ri
+
+    duration = (Time.now - start).to_i
+    names    = specs.map(&:name).join ', '
+
+    say "Done installing documentation for #{names} after #{duration} seconds"
+  end
+
+  def self.remove uninstaller
+    new(uninstaller.spec).remove
+  end
+
+  ##
+  # Loads the RDoc generator
+
+  def self.load_rdoc
+    return if @rdoc_version
+
+    require_relative 'rdoc'
+
+    @rdoc_version = Gem::Version.new ::RDoc::VERSION
+  end
+
+  ##
+  # Creates a new documentation generator for +spec+.  RDoc and ri data
+  # generation can be enabled or disabled through +generate_rdoc+ and
+  # +generate_ri+ respectively.
+  #
+  # Only +generate_ri+ is enabled by default.
+
+  def initialize spec, generate_rdoc = false, generate_ri = true
+    @doc_dir   = spec.doc_dir
+    @force     = false
+    @rdoc      = nil
+    @spec      = spec
+
+    @generate_rdoc = generate_rdoc
+    @generate_ri   = generate_ri
+
+    @rdoc_dir = spec.doc_dir 'rdoc'
+    @ri_dir   = spec.doc_dir 'ri'
+  end
+
+  ##
+  # Removes legacy rdoc arguments from +args+
+  #--
+  # TODO move to RDoc::Options
+
+  def delete_legacy_args args
+    args.delete '--inline-source'
+    args.delete '--promiscuous'
+    args.delete '-p'
+    args.delete '--one-file'
+  end
+
+  ##
+  # Generates documentation using the named +generator+ ("darkfish" or "ri")
+  # and following the given +options+.
+  #
+  # Documentation will be generated into +destination+
+
+  def document generator, options, destination
+    generator_name = generator
+
+    options = options.dup
+    options.exclude ||= [] # TODO maybe move to RDoc::Options#finish
+    options.setup_generator generator
+    options.op_dir = destination
+    Dir.chdir @spec.full_gem_path do
+      options.finish
+    end
+
+    generator = options.generator.new @rdoc.store, options
+
+    @rdoc.options = options
+    @rdoc.generator = generator
+
+    say "Installing #{generator_name} documentation for #{@spec.full_name}"
+
+    FileUtils.mkdir_p options.op_dir
+
+    Dir.chdir options.op_dir do
+      begin
+        @rdoc.class.current = @rdoc
+        @rdoc.generator.generate
+      ensure
+        @rdoc.class.current = nil
+      end
+    end
+  end
+
+  ##
+  # Generates RDoc and ri data
+
+  def generate
+    return if @spec.default_gem?
+    return unless @generate_ri or @generate_rdoc
+
+    setup
+
+    options = nil
+
+    args = @spec.rdoc_options
+    args.concat @spec.source_paths
+    args.concat @spec.extra_rdoc_files
+
+    case config_args = Gem.configuration[:rdoc]
+    when String then
+      args = args.concat config_args.split(' ')
+    when Array then
+      args = args.concat config_args
+    end
+
+    delete_legacy_args args
+
+    Dir.chdir @spec.full_gem_path do
+      options = ::RDoc::Options.new
+      options.default_title = "#{@spec.full_name} Documentation"
+      options.parse args
+    end
+
+    options.quiet = !Gem.configuration.really_verbose
+
+    @rdoc = new_rdoc
+    @rdoc.options = options
+
+    store = RDoc::Store.new
+    store.encoding = options.encoding
+    store.dry_run  = options.dry_run
+    store.main     = options.main_page
+    store.title    = options.title
+
+    @rdoc.store = store
+
+    say "Parsing documentation for #{@spec.full_name}"
+
+    Dir.chdir @spec.full_gem_path do
+      @rdoc.parse_files options.files
+    end
+
+    document 'ri',       options, @ri_dir if
+      @generate_ri   and (@force or not File.exist? @ri_dir)
+
+    document 'darkfish', options, @rdoc_dir if
+      @generate_rdoc and (@force or not File.exist? @rdoc_dir)
+  end
+
+  ##
+  # #new_rdoc creates a new RDoc instance.  This method is provided only to
+  # make testing easier.
+
+  def new_rdoc # :nodoc:
+    ::RDoc::RDoc.new
+  end
+
+  ##
+  # Is rdoc documentation installed?
+
+  def rdoc_installed?
+    File.exist? @rdoc_dir
+  end
+
+  ##
+  # Removes generated RDoc and ri data
+
+  def remove
+    base_dir = @spec.base_dir
+
+    raise Gem::FilePermissionError, base_dir unless File.writable? base_dir
+
+    FileUtils.rm_rf @rdoc_dir
+    FileUtils.rm_rf @ri_dir
+  end
+
+  ##
+  # Is ri data installed?
+
+  def ri_installed?
+    File.exist? @ri_dir
+  end
+
+  ##
+  # Prepares the spec for documentation generation
+
+  def setup
+    self.class.load_rdoc
+
+    raise Gem::FilePermissionError, @doc_dir if
+      File.exist?(@doc_dir) and not File.writable?(@doc_dir)
+
+    FileUtils.mkdir_p @doc_dir unless File.exist? @doc_dir
+  end
+
+end
+
 # This class is referenced by RubyGems to create documents.
-# Now, methods are moved to rubygems_plugin.rb.
+# All implementations are moved to the above RubyGemsHook.
+#
+# This class does nothing when this RDoc is installed as a normal gem
+# or a bundled gem.
 #
-# When old version RDoc is not used,
-# this class is not used from RubyGems too.
-# Then, remove this class.
+# This class does generate/remove documents for compatibility when
+# this RDoc is installed as a default gem.
 #
+# We can remove this when all maintained RubyGems remove
+# `rubygems/rdoc.rb`.
 module RDoc
   class RubygemsHook
-    def initialize(spec); end
+    def self.default_gem?
+      File.exist?(File.join(__dir__, "..", "rubygems_plugin.rb"))
+    end
+
+    def initialize(spec)
+      @spe = spec
+    end
+
+    def remove
+      # Do nothing if this is NOT a default gem.
+      return unless self.class.default_gem?
+
+      # Remove generate document for compatibility if this is a
+      # default gem.
+      RubyGemsHook.new(@spec).remove
+    end
 
-    def remove; end
+    def self.generation_hook installer, specs
+      # Do nothing if this is NOT a default gem.
+      return unless default_gem?
 
-    def self.generation_hook installer, specs; end
+      # Generate document for compatibility if this is a default gem.
+      RubyGemsHook.generation_hook(installer, specs)
+    end
   end
 end