* object.c (rb_obj_singleton_class): new method

  Kernel#singleton_class.  [ruby-core:21702]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27022 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 21 insertions, 0 deletions

diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 0a49422074..63c1d32bef 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -561,4 +561,25 @@ class TestObject < Test::Unit::TestCase
       end
     end.call
   end
+
+  def test_singleton_class
+    x = Object.new
+    xs = class << x; self; end
+    assert_equal(xs, x.singleton_class)
+
+    y = Object.new
+    ys = y.singleton_class
+    assert_equal(class << y; self; end, ys)
+
+    assert_equal(NilClass, nil.singleton_class)
+    assert_equal(TrueClass, true.singleton_class)
+    assert_equal(FalseClass, false.singleton_class)
+
+    assert_raise(TypeError) do
+      123.singleton_class
+    end
+    assert_raise(TypeError) do
+      :foo.singleton_class
+    end
+  end
 end