Add spec for attr_writer/attr_accessor methods on a frozen object

Author: eregon

spec/ruby/core/module/attr_accessor_spec.rb

@@ -33,7 +33,20 @@ class TrueClass
       attr_accessor :spec_attr_accessor
     end
 
-    -> { true.spec_attr_accessor = "a" }.should raise_error(RuntimeError)
+    -> { true.spec_attr_accessor = "a" }.should raise_error(FrozenError)
+  end
+
+  it "raises FrozenError if the receiver if frozen" do
+    c = Class.new do
+      attr_accessor :foo
+    end
+    obj = c.new
+    obj.foo = 1
+    obj.foo.should == 1
+
+    obj.freeze
+    -> { obj.foo = 42 }.should raise_error(FrozenError)
+    obj.foo.should == 1
   end
 
   it "converts non string/symbol names to strings using to_str" do

spec/ruby/core/module/attr_writer_spec.rb

@@ -29,7 +29,17 @@ class TrueClass
       attr_writer :spec_attr_writer
     end
 
-    -> { true.spec_attr_writer = "a" }.should raise_error(RuntimeError)
+    -> { true.spec_attr_writer = "a" }.should raise_error(FrozenError)
+  end
+
+  it "raises FrozenError if the receiver if frozen" do
+    c = Class.new do
+      attr_writer :foo
+    end
+    obj = c.new
+    obj.freeze
+
+    -> { obj.foo = 42 }.should raise_error(FrozenError)
   end
 
   it "converts non string/symbol names to strings using to_str" do