From 66f968c9de89904a645a4e1587081974a119ef7e Mon Sep 17 00:00:00 2001
From: Sushanth Sathesh Rao <57192414+raosush@users.noreply.github.com>
Date: Tue, 6 Sep 2022 14:26:49 +0530
Subject: [PATCH] RDoc: Add support for generics in RDoc

---
 lib/rdoc_plugin/parser.rb | 17 +++++++++++++++--
 stdlib/rdoc/0/rdoc.rbs    | 23 +++++++++++++++++++++--
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/lib/rdoc_plugin/parser.rb b/lib/rdoc_plugin/parser.rb
index 4f02e04e4..ee267d3d6 100644
--- a/lib/rdoc_plugin/parser.rb
+++ b/lib/rdoc_plugin/parser.rb
@@ -52,14 +52,27 @@ def parse_member(decl:, context:, outer_name: nil)
 
       def parse_class_decl(decl:, context:, outer_name: nil)
         full_name = fully_qualified_name(outer_name: outer_name, decl: decl)
-        klass = context.add_class(RDoc::NormalClass, full_name.to_s, decl.super_class&.name&.to_s || "::Object")
+        klass = context.add_class(RDoc::NormalClass, full_name.to_s, decl.super_class&.name&.to_s || "::Object",
+                                  decl.type_params.map do |type_param|
+                                    RDoc::TypeParameter.new(type_param.name.to_s,
+                                                        type_param.variance,
+                                                        type_param.unchecked?,
+                                                        type_param.upper_bound&.name&.to_s)
+                                    end
+                                  )
         klass.add_comment(construct_comment(context: context, comment: comment_string(decl)), context) if decl.comment
         decl.members.each { |member| parse_member(decl: member, context: context, outer_name: full_name) }
       end
 
       def parse_module_decl(decl:, context:, outer_name: nil)
         full_name = fully_qualified_name(outer_name: outer_name, decl: _ = decl)
-        kmodule = context.add_module(RDoc::NormalModule, full_name.to_s)
+        kmodule = context.add_module(RDoc::NormalModule, full_name.to_s,
+                                     decl.type_params.map do |type_param|
+                                       RDoc::TypeParameter.new(type_param.name.to_s,
+                                                           type_param.variance,
+                                                           type_param.unchecked?,
+                                                           type_param.upper_bound&.name&.to_s)
+                                       end)
         kmodule.add_comment(construct_comment(context: context, comment: comment_string(decl)), context) if decl.comment
         decl.members.each { |member| parse_member(decl: member, context: context, outer_name: full_name) }
       end
diff --git a/stdlib/rdoc/0/rdoc.rbs b/stdlib/rdoc/0/rdoc.rbs
index 73ec3458d..89f360cff 100644
--- a/stdlib/rdoc/0/rdoc.rbs
+++ b/stdlib/rdoc/0/rdoc.rbs
@@ -228,7 +228,7 @@ module RDoc
     # later sees `class Container`.  `add_class` automatically upgrades `given_name`
     # to a class in this case.
     #
-    def add_class: (class_types class_type, ::String given_name, ?::String superclass) -> (RDoc::NormalClass | RDoc::SingleClass)
+    def add_class: (class_types class_type, ::String given_name, ?::String superclass, ?Array[RDoc::TypeParameter]) -> (RDoc::NormalClass | RDoc::SingleClass)
 
     # <!--
     #   rdoc-file=lib/rdoc/context.rb
@@ -271,7 +271,7 @@ module RDoc
     # Adds a module named `name`.  If RDoc already knows `name` is a class then that
     # class is returned instead.  See also #add_class.
     #
-    def add_module: (singleton(RDoc::NormalModule) class_type, String name) -> RDoc::NormalModule
+    def add_module: (singleton(RDoc::NormalModule) class_type, String name, ?Array[RDoc::TypeParameter]) -> RDoc::NormalModule
 
     # <!--
     #   rdoc-file=lib/rdoc/context.rb
@@ -749,6 +749,25 @@ module RDoc
     def initialize: (String? text, String name, String old_name, RDoc::Comment? comment, ?bool `singleton`) -> void
   end
 
+  class TypeParameter < CodeObject
+    type variance = :invariant | :covariant | :contravariant
+
+    attr_reader name: String
+    attr_reader variance: variance
+    attr_reader upper_bound: String?
+    attr_reader `unchecked`: bool
+
+    def initialize: (String name, Symbol variance, ?bool `unchecked`, ?String? upper_bound) -> void
+
+    def ==: (untyped other) -> bool
+
+    alias eql? ==
+
+    def unchecked?: () -> bool
+
+    def to_s: () -> String
+  end
+
   # <!-- rdoc-file=lib/rdoc/stats.rb -->
   # RDoc statistics collector which prints a summary and report of a project's
   # documentation totals.