Add separate test to ensure that `delegate` with `:private` option returns correct value

Remove extra comments `# Asking for private method` in activesupport/test/core_ext/module_test.rb
Improve docs of using `delegate` with `:private`
Update changelog of #31944

1 files changed, 16 insertions, 6 deletions

diff --git a/activesupport/test/core_ext/module_test.rb b/activesupport/test/core_ext/module_test.rb
index 36cfd885d7..04692f1484 100644
--- a/activesupport/test/core_ext/module_test.rb
+++ b/activesupport/test/core_ext/module_test.rb
@@ -482,19 +482,29 @@ class ModuleTest < ActiveSupport::TestCase
       def initialize(place)
         @place = place
       end
-    end
 
-    assert_equal %i(the_street the_city),
-      location.delegate(:street, :city, to: :@place, prefix: :the, private: true)
+      delegate(:street, :city, to: :@place, prefix: :the, private: true)
+    end
 
     place = location.new(Somewhere.new("Such street", "Sad city"))
 
-    assert_not_respond_to place, :street
-    assert_not_respond_to place, :city
-
     assert_not_respond_to place, :the_street
     assert place.respond_to?(:the_street, true)
     assert_not_respond_to place, :the_city
     assert place.respond_to?(:the_city, true)
   end
+
+  def test_delegate_with_private_option_returns_names_of_delegate_methods
+    location = Class.new do
+      def initialize(place)
+        @place = place
+      end
+    end
+
+    assert_equal [:street, :city],
+      location.delegate(:street, :city, to: :@place, private: true)
+
+    assert_equal [:the_street, :the_city],
+      location.delegate(:street, :city, to: :@place, prefix: :the, private: true)
+  end
 end