1 files changed, 27 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/singleton_class_spec.rb b/spec/ruby/core/kernel/singleton_class_spec.rb
new file mode 100644
index 0000000000..b5e0703905
--- /dev/null
+++ b/spec/ruby/core/kernel/singleton_class_spec.rb
@@ -0,0 +1,27 @@
+describe "Kernel#singleton_class" do
+  it "returns class extended from an object" do
+    x = Object.new
+    xs = class << x; self; end
+    xs.should == x.singleton_class
+  end
+
+  it "returns NilClass for nil" do
+    nil.singleton_class.should == NilClass
+  end
+
+  it "returns TrueClass for true" do
+    true.singleton_class.should == TrueClass
+  end
+
+  it "returns FalseClass for false" do
+    false.singleton_class.should == FalseClass
+  end
+
+  it "raises TypeError for Fixnum" do
+    lambda { 123.singleton_class }.should raise_error(TypeError)
+  end
+
+  it "raises TypeError for Symbol" do
+    lambda { :foo.singleton_class }.should raise_error(TypeError)
+  end
+end