Add Refinement#target and deprecate Refinement#refined_class

[Feature #19714]

Author: shugo

NEWS.md

@@ -56,6 +56,11 @@ Note: We're only listing outstanding class updates.
       for long running applications. The actual optimizations performed are entirely
       implementation specific and may change in the future without notice. [[Feature #18885]
 
+* Refinement
+
+    * Add Refinement#target as an alternative of Refinement#refined_class.
+      Refinement#refined_class is deprecated and will be removed in Ruby 3.4. [[Feature #19714]]
+
 ## Stdlib updates
 
 The following default gems are updated.

eval.c

@@ -1346,9 +1346,9 @@ rb_using_module(const rb_cref_t *cref, VALUE module)
 
 /*
  *  call-seq:
- *     refined_class    -> class
+ *     target    -> class
  *
- *  Return the class refined by the receiver.
+ *  Return the class or module refined by the receiver.
  */
 VALUE
 rb_refinement_module_get_refined_class(VALUE module)
@@ -1359,6 +1359,19 @@ rb_refinement_module_get_refined_class(VALUE module)
     return rb_attr_get(module, id_refined_class);
 }
 
+/*
+ *  call-seq:
+ *     refined_class    -> class
+ *
+ *  Return the class refined by the receiver.
+ */
+static VALUE
+rb_refinement_refined_class(VALUE module)
+{
+    rb_warn_deprecated_to_remove("3.4", "Refinement#refined_class", "Refinement#target");
+    return rb_refinement_module_get_refined_class(module);
+}
+
 static void
 add_activated_refinement(VALUE activated_refinements,
                          VALUE klass, VALUE refinement)
@@ -2067,7 +2080,8 @@ Init_eval(void)
                                rb_mod_s_used_refinements, 0);
     rb_undef_method(rb_cClass, "refine");
     rb_define_private_method(rb_cRefinement, "import_methods", refinement_import_methods, -1);
-    rb_define_method(rb_cRefinement, "refined_class", rb_refinement_module_get_refined_class, 0);
+    rb_define_method(rb_cRefinement, "target", rb_refinement_module_get_refined_class, 0);
+    rb_define_method(rb_cRefinement, "refined_class", rb_refinement_refined_class, 0);
     rb_undef_method(rb_cRefinement, "append_features");
     rb_undef_method(rb_cRefinement, "prepend_features");
     rb_undef_method(rb_cRefinement, "extend_object");

test/ruby/test_refinement.rb

@@ -1798,15 +1798,17 @@ def test_refinements
     assert_equal([int_refinement, str_refinement], m.refinements)
   end
 
-  def test_refined_class
+  def test_target
     refinements = Module.new {
       refine Integer do
       end
 
       refine String do
       end
     }.refinements
+    assert_equal(Integer, refinements[0].target)
     assert_equal(Integer, refinements[0].refined_class)
+    assert_equal(String, refinements[1].target)
     assert_equal(String, refinements[1].refined_class)
   end