Style/AccessorGrouping: Fix detection of Sorbet sig {} blocks

- Sorbet `sig { returns(Integer) }` annotations above `attr_reader`
  methods should be ignored after
  9921cdc, per the docs, but they
  weren't being.
- Sorbet `sig {}` constructs are blocks (hence the braces), not
  `send_type?` directly.
- Hence, we now check if the previous expression is a block and if so,
  descend into its child nodes until we find a `send_type`, then use
  that to determine if the accessor is groupable.
- Relates to rubocop#11596.

changelog/fix_style_accessor_grouping_fix_detection_of_sorbet.md

@@ -0,0 +1 @@
+* [#11650](https://github.com/rubocop/rubocop/pull/11650): `Style/AccessorGrouping`: Fix detection of Sorbet `sig {}` blocks. ([@issyl0][])

lib/rubocop/cop/style/accessor_grouping.rb

@@ -14,19 +14,23 @@ module Style
       #   # bad
       #   class Foo
       #     attr_reader :bar
+      #     attr_reader :bax
       #     attr_reader :baz
       #   end
       #
       #   # good
       #   class Foo
-      #     attr_reader :bar, :baz
+      #     attr_reader :bar, :bax, :baz
       #   end
       #
       #   # good
       #   class Foo
       #     # may be intended comment for bar.
       #     attr_reader :bar
       #
+      #     sig { returns(String) }
+      #     attr_reader :bax
+      #
       #     may_be_intended_annotation :baz
       #     attr_reader :baz
       #   end
@@ -90,6 +94,14 @@ def previous_line_comment?(node)
 
         def groupable_accessor?(node)
           return true unless (previous_expression = node.left_siblings.last)
+
+          # Accessors with Sorbet `sig { ... }` blocks shouldn't be groupable.
+          if previous_expression.block_type?
+            previous_expression.child_nodes.each do |child_node|
+              break previous_expression = child_node if child_node.send_type?
+            end
+          end
+
           return true unless previous_expression.send_type?
 
           previous_expression.attribute_accessor? || previous_expression.access_modifier?

spec/rubocop/cop/style/accessor_grouping_spec.rb

@@ -127,11 +127,16 @@ class Foo
     it 'does not register an offense for accessors with other methods' do
       expect_no_offenses(<<~RUBY)
         class Foo
+          extend T::Sig
+
           annotation_method :one
           attr_reader :one
 
           annotation_method :two
           attr_reader :two
+
+          sig { returns(Integer) }
+          attr_reader :three
         end
       RUBY
     end