1 files changed, 35 insertions, 1 deletions
diff --git a/test/ruby/test_objectspace.rb b/test/ruby/test_objectspace.rb
index ef85edc5ee..a479547599 100644
--- a/test/ruby/test_objectspace.rb
+++ b/test/ruby/test_objectspace.rb
@@ -94,7 +94,7 @@ End
   end
 
   def test_finalizer
-    assert_in_out_err(["-e", <<-END], "", %w(:ok :ok :ok :ok), [])
+    assert_in_out_err(["-e", <<-END], "", %w(:ok :ok :ok), [])
       a = []
       ObjectSpace.define_finalizer(a) { p :ok }
       b = a.dup
@@ -137,6 +137,25 @@ End
     }
   end
 
+  def test_finalizer_copy
+    assert_in_out_err(["-e", <<~'RUBY'], "", %w(:ok), [])
+      def fin
+        ids = Set.new
+        ->(id) { puts "object_id (#{id}) reused" unless ids.add?(id) }
+      end
+
+      OBJ = Object.new
+      ObjectSpace.define_finalizer(OBJ, fin)
+      OBJ.freeze
+
+      10.times do
+        OBJ.clone
+      end
+
+      p :ok
+    RUBY
+  end
+
   def test_finalizer_with_super
     assert_in_out_err(["-e", <<-END], "", %w(:ok), [])
       class A
@@ -265,6 +284,21 @@ End
     end;
   end
 
+  def test_id2ref_table_build
+    assert_separately([], <<-End)
+      10.times do
+        Object.new.object_id
+      end
+
+      GC.start(immediate_mark: false)
+
+      obj = Object.new
+      EnvUtil.suppress_warning do
+        assert_equal obj, ObjectSpace._id2ref(obj.object_id)
+      end
+    End
+  end
+
   def test_each_object_singleton_class
     assert_separately([], <<-End)
       class C