1 files changed, 79 insertions, 0 deletions
diff --git a/spec/ruby/language/undef_spec.rb b/spec/ruby/language/undef_spec.rb
new file mode 100644
index 0000000000..98ecd99c21
--- /dev/null
+++ b/spec/ruby/language/undef_spec.rb
@@ -0,0 +1,79 @@
+require_relative '../spec_helper'
+
+describe "The undef keyword" do
+  describe "undefines a method" do
+    before :each do
+      @undef_class = Class.new do
+        def meth(o); o; end
+      end
+      @obj = @undef_class.new
+      @obj.meth(5).should == 5
+    end
+
+    it "with an identifier" do
+      @undef_class.class_eval do
+        undef meth
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+
+    it "with a simple symbol" do
+      @undef_class.class_eval do
+        undef :meth
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+
+    it "with a single quoted symbol" do
+      @undef_class.class_eval do
+        undef :'meth'
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+
+    it "with a double quoted symbol" do
+      @undef_class.class_eval do
+        undef :"meth"
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+
+    it "with an interpolated symbol" do
+      @undef_class.class_eval do
+        undef :"#{'meth'}"
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+
+    it "with an interpolated symbol when interpolated expression is not a String literal" do
+      @undef_class.class_eval do
+        undef :"#{'meth'.to_sym}"
+      end
+      -> { @obj.meth(5) }.should.raise(NoMethodError)
+    end
+  end
+
+  it "allows undefining multiple methods at a time" do
+    undef_multiple = Class.new do
+      def method1; end
+      def method2; :nope; end
+
+      undef :method1, :method2
+    end
+
+    obj = undef_multiple.new
+    obj.respond_to?(:method1).should == false
+    obj.respond_to?(:method2).should == false
+  end
+
+  it "raises a NameError when passed a missing name" do
+    Class.new do
+      -> {
+        undef not_exist
+      }.should.raise(NameError) { |e|
+        # a NameError and not a NoMethodError
+        e.class.should == NameError
+      }
+    end
+  end
+end