From cbd54cba03d0a0ecae1df590ca78751362fda826 Mon Sep 17 00:00:00 2001
From: Soutaro Matsumoto <matsumoto@soutaro.com>
Date: Tue, 8 Feb 2022 21:23:13 +0900
Subject: [PATCH] [ruby/rdoc] Skip parentheses on singleton class declaration

https://github.com/ruby/rdoc/commit/b6c6d4f978
---
 lib/rdoc/parser/ruby.rb            | 25 ++++++++++++++++++++++++-
 test/rdoc/test_rdoc_parser_ruby.rb | 13 +++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/lib/rdoc/parser/ruby.rb b/lib/rdoc/parser/ruby.rb
index e546fe2141..3c5f79632c 100644
--- a/lib/rdoc/parser/ruby.rb
+++ b/lib/rdoc/parser/ruby.rb
@@ -399,6 +399,29 @@ class RDoc::Parser::Ruby < RDoc::Parser
     return [container, name_t, given_name, new_modules]
   end
 
+  ##
+  # Skip opening parentheses and yield the block.
+  # Skip closing parentheses too when exists.
+
+  def skip_parentheses(&block)
+    left_tk = peek_tk
+
+    if :on_lparen == left_tk[:kind]
+      get_tk
+
+      ret = skip_parentheses(&block)
+
+      right_tk = peek_tk
+      if :on_rparen == right_tk[:kind]
+        get_tk
+      end
+
+      ret
+    else
+      yield
+    end
+  end
+
   ##
   # Return a superclass, which can be either a constant of an expression
 
@@ -833,7 +856,7 @@ class RDoc::Parser::Ruby < RDoc::Parser
       cls = parse_class_regular container, declaration_context, single,
         name_t, given_name, comment
     elsif name_t[:kind] == :on_op && name_t[:text] == '<<'
-      case name = get_class_specification
+      case name = skip_parentheses { get_class_specification }
       when 'self', container.name
         read_documentation_modifiers cls, RDoc::CLASS_MODIFIERS
         parse_statements container, SINGLE
diff --git a/test/rdoc/test_rdoc_parser_ruby.rb b/test/rdoc/test_rdoc_parser_ruby.rb
index 337cf9ea1a..b3026b14ca 100644
--- a/test/rdoc/test_rdoc_parser_ruby.rb
+++ b/test/rdoc/test_rdoc_parser_ruby.rb
@@ -4345,4 +4345,17 @@ end
     assert_equal 'Hello', meth.comment.text
   end
 
+  def test_parenthesized_cdecl
+    util_parser <<-RUBY
+module DidYouMean
+  class << (NameErrorCheckers = Object.new)
+  end
+end
+    RUBY
+
+    @parser.scan
+
+    refute_predicate @store.find_class_or_module('DidYouMean'), :nil?
+    refute_predicate @store.find_class_or_module('DidYouMean::NameErrorCheckers'), :nil?
+  end
 end