Embed mixed-in methods and constants with --embed-mixins

When `--embed-mixins` option is set:

- methods from an `extend`ed module are documented as singleton methods
- attrs from an `extend`ed module are documented as class attributes
- methods from an `include`ed module are documented as instance methods
- attrs from an `include`ed module are documented as instance attributes
- constants from an `include`ed module are documented

Sections are created when needed, and Darkfish's template annotates
each of these mixed-in CodeObjects. We also respect the mixin methods'
visibility.

This feature is inspired by Yard's option of the same name.

lib/rdoc/class_module.rb

@@ -223,6 +223,7 @@ def comment= comment # :nodoc:
   def complete min_visibility
     update_aliases
     remove_nodoc_children
+    embed_mixins
     update_includes
     remove_invisible min_visibility
   end
@@ -798,5 +799,41 @@ def update_extends
     extends.uniq!
   end
 
-end
+  def embed_mixins
+    return unless options.embed_mixins
+
+    includes.each do |include|
+      next if String === include.module
+      include.module.method_list.each do |code_object|
+        add_method(prepare_to_embed(code_object))
+      end
+      include.module.constants.each do |code_object|
+        add_constant(prepare_to_embed(code_object))
+      end
+      include.module.attributes.each do |code_object|
+        add_attribute(prepare_to_embed(code_object))
+      end
+    end
+
+    extends.each do |ext|
+      next if String === ext.module
+      ext.module.method_list.each do |code_object|
+        add_method(prepare_to_embed(code_object, true))
+      end
+      ext.module.attributes.each do |code_object|
+        add_attribute(prepare_to_embed(code_object, true))
+      end
+    end
+  end
 
+  private
+
+  def prepare_to_embed(code_object, singleton=false)
+    code_object = code_object.dup
+    code_object.mixin_from = code_object.parent
+    code_object.singleton = true if singleton
+    set_current_section(code_object.section.title, code_object.section.comment)
+    self.visibility = code_object.visibility
+    code_object
+  end
+end

lib/rdoc/code_object.rb

@@ -96,6 +96,11 @@ class RDoc::CodeObject
 
   attr_accessor :viewer
 
+  ##
+  # When mixed-in to a class, this points to the Context in which it was originally defined.
+
+  attr_accessor :mixin_from
+
   ##
   # Creates a new CodeObject that will document itself and its children
 

lib/rdoc/generator/template/darkfish/class.rhtml

@@ -53,7 +53,13 @@
       <%- constants.each do |const| -%>
         <dt id="<%= const.name %>"><%= const.name %>
         <%- if const.comment then -%>
-        <dd><%= const.description.strip %>
+        <dd>
+          <%- if const.mixin_from then -%>
+            <div class="mixin-from">
+              Included from <a href="<%= klass.aref_to(const.mixin_from.path)%>"><%= const.mixin_from.full_name %></a>
+            </div>
+          <%- end -%>
+          <%= const.description.strip %>
         <%- else -%>
         <dd class="missing-docs">(Not documented)
         <%- end -%>
@@ -76,6 +82,11 @@
         </div>
 
         <div class="method-description">
+        <%- if attrib.mixin_from then -%>
+          <div class="mixin-from">
+            <%= attrib.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(attrib.mixin_from.path)%>"><%= attrib.mixin_from.full_name %></a>
+          </div>
+        <%- end -%>
         <%- if attrib.comment then -%>
         <%= attrib.description.strip %>
         <%- else -%>
@@ -124,6 +135,11 @@
         </div>
 
         <div class="method-description">
+          <%- if method.mixin_from then -%>
+            <div class="mixin-from">
+              <%= method.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(method.mixin_from.path)%>"><%= method.mixin_from.full_name %></a>
+            </div>
+          <%- end -%>
           <%- if method.comment then -%>
           <%= method.description.strip %>
           <%- else -%>

lib/rdoc/generator/template/darkfish/css/rdoc.css

@@ -586,6 +586,13 @@ main .aliases {
   font-style: italic;
   cursor: default;
 }
+
+main .mixin-from {
+  font-size: 80%;
+  font-style: italic;
+  margin-bottom: 0.75em;
+}
+
 main .method-description ul {
   margin-left: 1.5em;
 }

lib/rdoc/options.rb

@@ -343,13 +343,19 @@ class RDoc::Options
   # Indicates if files of test suites should be skipped
   attr_accessor :skip_tests
 
+  ##
+  # Embed mixin methods, attributes, and constants into class documentation. Set via
+  # +--[no-]embed-mixins+ (Default is +false+.)
+  attr_accessor :embed_mixins
+
   def initialize loaded_options = nil # :nodoc:
     init_ivars
     override loaded_options if loaded_options
   end
 
   def init_ivars # :nodoc:
     @dry_run = false
+    @embed_mixins = false
     @exclude = %w[
       ~\z \.orig\z \.rej\z \.bak\z
       \.gemspec\z
@@ -400,6 +406,7 @@ def init_with map # :nodoc:
     @encoding = encoding ? Encoding.find(encoding) : encoding
 
     @charset        = map['charset']
+    @embed_mixins   = map['embed_mixins']
     @exclude        = map['exclude']
     @generator_name = map['generator_name']
     @hyperlink_all  = map['hyperlink_all']
@@ -431,6 +438,7 @@ def override map # :nodoc:
     end
 
     @charset        = map['charset']        if map.has_key?('charset')
+    @embed_mixins   = map['embed_mixins']   if map.has_key?('embed_mixins')
     @exclude        = map['exclude']        if map.has_key?('exclude')
     @generator_name = map['generator_name'] if map.has_key?('generator_name')
     @hyperlink_all  = map['hyperlink_all']  if map.has_key?('hyperlink_all')
@@ -459,11 +467,12 @@ def override map # :nodoc:
   def == other # :nodoc:
     self.class === other and
       @encoding       == other.encoding       and
+      @embed_mixins   == other.embed_mixins   and
       @generator_name == other.generator_name and
       @hyperlink_all  == other.hyperlink_all  and
       @line_numbers   == other.line_numbers   and
       @locale         == other.locale         and
-      @locale_dir     == other.locale_dir and
+      @locale_dir     == other.locale_dir     and
       @main_page      == other.main_page      and
       @markup         == other.markup         and
       @op_dir         == other.op_dir         and
@@ -841,6 +850,14 @@ def parse argv
 
       opt.separator nil
 
+      opt.on("--[no-]embed-mixins",
+             "Embed mixin methods, attributes, and constants",
+             "into class documentation. (default false)") do |value|
+        @embed_mixins = value
+      end
+
+      opt.separator nil
+
       markup_formats = RDoc::Text::MARKUP_FORMAT.keys.sort
 
       opt.on("--markup=MARKUP", markup_formats,

test/rdoc/test_rdoc_class_module.rb

@@ -1500,4 +1500,132 @@ def test_update_extends_with_colons
     assert_equal [a, c], @c1.extends
   end
 
+  class TestRDocClassModuleMixins < XrefTestCase
+    def setup
+      super
+
+      klass_tl = @store.add_file("klass.rb")
+      @klass = klass_tl.add_class(RDoc::NormalClass, "Klass")
+
+      incmod_tl = @store.add_file("incmod.rb")
+      @incmod = incmod_tl.add_module(RDoc::NormalModule, "Incmod")
+
+      incmod_const = @incmod.add_constant(RDoc::Constant.new("INCMOD_CONST_WITHOUT_A_SECTION", nil, ""))
+      incmod_const = @incmod.add_constant(RDoc::Constant.new("INCMOD_CONST", nil, ""))
+      incmod_const.section = @incmod.add_section("Incmod const section")
+
+      incmod_method = @incmod.add_method(RDoc::AnyMethod.new(nil, "incmod_method_without_a_section"))
+      incmod_method = @incmod.add_method(RDoc::AnyMethod.new(nil, "incmod_method"))
+      incmod_method.section = @incmod.add_section("Incmod method section")
+
+      incmod_attr = @incmod.add_attribute(RDoc::Attr.new(nil, "incmod_attr_without_a_section", "RW", ""))
+      incmod_attr = @incmod.add_attribute(RDoc::Attr.new(nil, "incmod_attr", "RW", ""))
+      incmod_attr.section = @incmod.add_section("Incmod attr section")
+
+      incmod_private_method = @incmod.add_method(RDoc::AnyMethod.new(nil, "incmod_private_method"))
+      incmod_private_method.visibility = :private
+
+      extmod_tl = @store.add_file("extmod.rb")
+      @extmod = extmod_tl.add_module(RDoc::NormalModule, "Extmod")
+
+      extmod_method = @extmod.add_method(RDoc::AnyMethod.new(nil, "extmod_method_without_a_section"))
+      extmod_method = @extmod.add_method(RDoc::AnyMethod.new(nil, "extmod_method"))
+      extmod_method.section = @extmod.add_section("Extmod method section")
+
+      extmod_attr = @extmod.add_attribute(RDoc::Attr.new(nil, "extmod_attr_without_a_section", "RW", "", true))
+      extmod_attr = @extmod.add_attribute(RDoc::Attr.new(nil, "extmod_attr", "RW", "", true))
+      extmod_attr.section = @extmod.add_section("Extmod attr section")
+
+      extmod_private_method = @extmod.add_method(RDoc::AnyMethod.new(nil, "extmod_private_method"))
+      extmod_private_method.visibility = :private
+
+      @klass.add_include(RDoc::Include.new("Incmod", nil))
+      @klass.add_extend(RDoc::Include.new("Extmod", nil))
+
+      @klass.add_include(RDoc::Include.new("ExternalInclude", nil))
+      @klass.add_extend(RDoc::Include.new("ExternalExtend", nil))
+    end
+
+    def test_embed_mixin_when_false_does_not_embed_anything
+      assert_false(@klass.options.embed_mixins)
+      @klass.complete(:protected)
+
+      refute_includes(@klass.constants.map(&:name), "INCMOD_CONST")
+      refute_includes(@klass.method_list.map(&:name), "incmod_method")
+      refute_includes(@klass.method_list.map(&:name), "extmod_method")
+      refute_includes(@klass.attributes.map(&:name), "incmod_attr")
+      refute_includes(@klass.attributes.map(&:name), "extmod_attr")
+    end
+
+    def test_embed_mixin_when_true_embeds_methods_and_constants
+      @klass.options.embed_mixins = true
+      @klass.complete(:protected)
+
+      # assert on presence and identity of methods and constants
+      constant = @klass.constants.find { |c| c.name == "INCMOD_CONST" }
+      assert(constant, "constant from included mixin should be present")
+      assert_equal(@incmod, constant.mixin_from)
+
+      instance_method = @klass.method_list.find { |m| m.name == "incmod_method" }
+      assert(instance_method, "instance method from included mixin should be present")
+      refute(instance_method.singleton)
+      assert_equal(@incmod, instance_method.mixin_from)
+
+      instance_attr = @klass.attributes.find { |a| a.name == "incmod_attr" }
+      assert(instance_attr, "instance attr from included mixin should be present")
+      refute(instance_attr.singleton)
+      assert_equal(@incmod, instance_attr.mixin_from)
+
+      refute(@klass.method_list.find { |m| m.name == "incmod_private_method" })
+
+      class_method = @klass.method_list.find { |m| m.name == "extmod_method" }
+      assert(class_method, "class method from extended mixin should be present")
+      assert(class_method.singleton)
+      assert_equal(@extmod, class_method.mixin_from)
+
+      class_attr = @klass.attributes.find { |a| a.name == "extmod_attr" }
+      assert(class_attr, "class attr from extended mixin should be present")
+      assert(class_attr.singleton)
+      assert_equal(@extmod, class_attr.mixin_from)
+
+      refute(@klass.method_list.find { |m| m.name == "extmod_private_method" })
+
+      # assert that sections are also imported
+      constant_section = @klass.sections.find { |s| s.title == "Incmod const section" }
+      assert(constant_section, "constant from included mixin should have a section")
+      assert_equal(constant_section, constant.section)
+
+      instance_method_section = @klass.sections.find { |s| s.title == "Incmod method section" }
+      assert(instance_method_section, "instance method from included mixin should have a section")
+      assert_equal(instance_method_section, instance_method.section)
+
+      instance_attr_section = @klass.sections.find { |s| s.title == "Incmod attr section" }
+      assert(instance_attr_section, "instance attr from included mixin should have a section")
+      assert_equal(instance_attr_section, instance_attr.section)
+
+      class_method_section = @klass.sections.find { |s| s.title == "Extmod method section" }
+      assert(class_method_section, "class method from extended mixin should have a section")
+      assert_equal(class_method_section, class_method.section)
+
+      class_attr_section = @klass.sections.find { |s| s.title == "Extmod attr section" }
+      assert(class_attr_section, "class attr from extended mixin should have a section")
+      assert_equal(class_attr_section, class_attr.section)
+
+      # and check that code objects without a section still have no section
+      constant = @klass.constants.find { |c| c.name == "INCMOD_CONST_WITHOUT_A_SECTION" }
+      assert_nil(constant.section.title)
+
+      instance_method = @klass.method_list.find { |c| c.name == "incmod_method_without_a_section" }
+      assert_nil(instance_method.section.title)
+
+      instance_attr = @klass.attributes.find { |c| c.name == "incmod_attr_without_a_section" }
+      assert_nil(instance_attr.section.title)
+
+      class_method = @klass.method_list.find { |c| c.name == "extmod_method_without_a_section" }
+      assert_nil(class_method.section.title)
+
+      class_attr = @klass.attributes.find { |c| c.name == "extmod_attr_without_a_section" }
+      assert_nil(class_attr.section.title)
+    end
+  end
 end

test/rdoc/test_rdoc_options.rb

@@ -65,6 +65,7 @@ def test_to_yaml
     expected = {
       'charset'              => 'UTF-8',
       'encoding'             => encoding,
+      'embed_mixins'         => false,
       'exclude'              => %w[~\z \.orig\z \.rej\z \.bak\z \.gemspec\z],
       'hyperlink_all'        => false,
       'line_numbers'         => false,
@@ -590,6 +591,20 @@ def test_parse_root
     assert_includes @options.rdoc_include, @options.root.to_s
   end
 
+  def test_parse_embed_mixins
+    assert_false(@options.embed_mixins)
+
+    out, err = capture_output { @options.parse(["--embed-mixins"]) }
+    assert_empty(out)
+    assert_empty(err)
+    assert_true(@options.embed_mixins)
+
+    out, err = capture_output { @options.parse(["--no-embed-mixins"]) }
+    assert_empty(out)
+    assert_empty(err)
+    assert_false(@options.embed_mixins)
+  end
+
   def test_parse_tab_width
     @options.parse %w[--tab-width=1]
     assert_equal 1, @options.tab_width