1 files changed, 146 insertions, 0 deletions
diff --git a/spec/ruby/core/module/method_added_spec.rb b/spec/ruby/core/module/method_added_spec.rb
new file mode 100644
index 0000000000..ec92cddc1e
--- /dev/null
+++ b/spec/ruby/core/module/method_added_spec.rb
@@ -0,0 +1,146 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Module#method_added" do
+  before :each do
+    ScratchPad.record []
+  end
+
+  it "is a private instance method" do
+    Module.should have_private_instance_method(:method_added)
+  end
+
+  it "returns nil in the default implementation" do
+    Module.new do
+      method_added(:test).should == nil
+    end
+  end
+
+  it "is called when a new instance method is defined in self" do
+    Module.new do
+      def self.method_added(name)
+        ScratchPad << name
+      end
+
+      def test() end
+      def test2() end
+      def test() end
+      alias_method :aliased_test, :test
+      alias aliased_test2 test
+    end
+
+    ScratchPad.recorded.should == [:test, :test2, :test, :aliased_test, :aliased_test2]
+  end
+
+  it "is not called when a singleton method is added" do
+    # obj.singleton_method_added is called instead
+    klass = Class.new
+    def klass.method_added(name)
+      ScratchPad << name
+    end
+
+    obj = klass.new
+    def obj.new_singleton_method
+    end
+
+    ScratchPad.recorded.should == []
+  end
+
+  it "is not called when a method is undefined in self" do
+    m = Module.new do
+      def method_to_undef
+      end
+
+      def self.method_added(name)
+        fail("method_added called by undef_method")
+      end
+
+      undef_method :method_to_undef
+    end
+    m.should_not have_method(:method_to_undef)
+  end
+
+  it "is not called when a method changes visibility" do
+    Module.new do
+      def public_method
+      end
+
+      def private_method
+      end
+
+      def self.method_added(name)
+        ScratchPad << name
+      end
+
+      public :public_method
+      private :public_method
+
+      private :private_method
+      public :private_method
+    end
+
+    ScratchPad.recorded.should == []
+  end
+
+  it "is called when using #private in a subclass" do
+    parent = Class.new do
+      def foo
+      end
+    end
+
+    Class.new(parent) do
+      def self.method_added(name)
+        ScratchPad << name
+      end
+
+      # Create an instance as that might initialize some method lookup caches, which is interesting to test
+      self.new.foo
+
+      private :foo
+      public :foo
+    end
+
+    ScratchPad.recorded.should == [:foo]
+  end
+
+  it "is not called when a method is copied via module_function, rather #singleton_method_added is called" do
+    Module.new do
+      def mod_function
+      end
+
+      def self.method_added(name)
+        ScratchPad << [:method_added, name]
+      end
+
+      def self.singleton_method_added(name)
+        ScratchPad << [:singleton_method_added, name]
+      end
+
+      ScratchPad.record []
+
+      module_function :mod_function
+    end
+
+    ScratchPad.recorded.should == [[:singleton_method_added, :mod_function]]
+  end
+
+  it "is called with a precise caller location with the line of the 'def'" do
+    line = nil
+
+    Module.new do
+      def self.method_added(name)
+        location = caller_locations(1, 1)[0]
+        ScratchPad << location.lineno
+      end
+
+      line = __LINE__
+      def first
+      end
+
+      def second
+      end
+    end
+
+    ScratchPad.recorded.should == [line + 1, line + 4]
+  end
+end