1 files changed, 171 insertions, 0 deletions
diff --git a/spec/ruby/core/module/alias_method_spec.rb b/spec/ruby/core/module/alias_method_spec.rb
new file mode 100644
index 0000000000..c36dedd2d8
--- /dev/null
+++ b/spec/ruby/core/module/alias_method_spec.rb
@@ -0,0 +1,171 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Module#alias_method" do
+  before :each do
+    @class = Class.new(ModuleSpecs::Aliasing)
+    @object = @class.new
+  end
+
+  it "makes a copy of the method" do
+    @class.make_alias :uno, :public_one
+    @class.make_alias :double, :public_two
+    @object.uno.should == @object.public_one
+    @object.double(12).should == @object.public_two(12)
+  end
+
+  it "creates methods that are == to each other" do
+    @class.make_alias :uno, :public_one
+    @object.method(:uno).should == @object.method(:public_one)
+  end
+
+  it "preserves the arguments information of the original methods" do
+    @class.make_alias :uno, :public_one
+    @class.make_alias :double, :public_two
+    @class.instance_method(:uno).parameters.should == @class.instance_method(:public_one).parameters
+    @class.instance_method(:double).parameters.should == @class.instance_method(:public_two).parameters
+  end
+
+  it "retains method visibility" do
+    @class.make_alias :private_ichi, :private_one
+    -> { @object.private_one  }.should raise_error(NameError)
+    -> { @object.private_ichi }.should raise_error(NameError)
+    @class.make_alias :public_ichi, :public_one
+    @object.public_ichi.should == @object.public_one
+    @class.make_alias :protected_ichi, :protected_one
+    -> { @object.protected_ichi }.should raise_error(NameError)
+  end
+
+  it "handles aliasing a stub that changes visibility" do
+    @class.__send__ :public, :private_one
+    @class.make_alias :was_private_one, :private_one
+    @object.was_private_one.should == 1
+  end
+
+  it "handles aliasing a method only present in a refinement" do
+    c = @class
+    Module.new do
+      refine c do
+        def uno_refined_method
+        end
+        alias_method :double_refined_method, :uno_refined_method
+        instance_method(:uno_refined_method).should == instance_method(:double_refined_method)
+      end
+    end
+  end
+
+  it "fails if origin method not found" do
+    -> { @class.make_alias :ni, :san }.should raise_error(NameError) { |e|
+      # a NameError and not a NoMethodError
+      e.class.should == NameError
+    }
+  end
+
+  it "raises FrozenError if frozen" do
+    @class.freeze
+    -> { @class.make_alias :uno, :public_one }.should raise_error(FrozenError)
+  end
+
+  it "converts the names using #to_str" do
+    @class.make_alias "un", "public_one"
+    @class.make_alias :deux, "public_one"
+    @class.make_alias "trois", :public_one
+    @class.make_alias :quatre, :public_one
+    name = mock('cinq')
+    name.should_receive(:to_str).any_number_of_times.and_return("cinq")
+    @class.make_alias name, "public_one"
+    @class.make_alias "cinq", name
+  end
+
+  it "raises a TypeError when the given name can't be converted using to_str" do
+    -> { @class.make_alias mock('x'), :public_one }.should raise_error(TypeError)
+  end
+
+  it "raises a NoMethodError if the given name raises a NoMethodError during type coercion using to_str" do
+    obj = mock("mock-name")
+    obj.should_receive(:to_str).and_raise(NoMethodError)
+    -> { @class.make_alias obj, :public_one }.should raise_error(NoMethodError)
+  end
+
+  it "is a public method" do
+    Module.should have_public_instance_method(:alias_method, false)
+  end
+
+  describe "returned value" do
+    it "returns symbol of the defined method name" do
+      @class.send(:alias_method, :checking_return_value, :public_one).should equal(:checking_return_value)
+      @class.send(:alias_method, 'checking_return_value', :public_one).should equal(:checking_return_value)
+    end
+  end
+
+  it "works in module" do
+    ModuleSpecs::Allonym.new.publish.should == :report
+  end
+
+  it "works on private module methods in a module that has been reopened" do
+    ModuleSpecs::ReopeningModule.foo.should == true
+    -> { ModuleSpecs::ReopeningModule.foo2 }.should_not raise_error(NoMethodError)
+  end
+
+  it "accesses a method defined on Object from Kernel" do
+    Kernel.should_not have_public_instance_method(:module_specs_public_method_on_object)
+
+    Kernel.should have_public_instance_method(:module_specs_alias_on_kernel)
+    Object.should have_public_instance_method(:module_specs_alias_on_kernel)
+  end
+
+  it "can call a method with super aliased twice" do
+    ModuleSpecs::AliasingSuper::Target.new.super_call(1).should == 1
+  end
+
+  it "preserves original super call after alias redefine" do
+    ModuleSpecs::AliasingSuper::RedefineAfterAlias.new.alias_super_call(1).should == 1
+  end
+
+  describe "aliasing special methods" do
+    before :all do
+      @class = ModuleSpecs::Aliasing
+      @subclass = ModuleSpecs::AliasingSubclass
+    end
+
+    it "keeps initialize private when aliasing" do
+      @class.make_alias(:initialize, :public_one)
+      @class.private_instance_methods.include?(:initialize).should be_true
+
+      @subclass.make_alias(:initialize, :public_one)
+      @subclass.private_instance_methods.include?(:initialize).should be_true
+    end
+
+    it "keeps initialize_copy private when aliasing" do
+      @class.make_alias(:initialize_copy, :public_one)
+      @class.private_instance_methods.include?(:initialize_copy).should be_true
+
+      @subclass.make_alias(:initialize_copy, :public_one)
+      @subclass.private_instance_methods.include?(:initialize_copy).should be_true
+    end
+
+    it "keeps initialize_clone private when aliasing" do
+      @class.make_alias(:initialize_clone, :public_one)
+      @class.private_instance_methods.include?(:initialize_clone).should be_true
+
+      @subclass.make_alias(:initialize_clone, :public_one)
+      @subclass.private_instance_methods.include?(:initialize_clone).should be_true
+    end
+
+    it "keeps initialize_dup private when aliasing" do
+      @class.make_alias(:initialize_dup, :public_one)
+      @class.private_instance_methods.include?(:initialize_dup).should be_true
+
+      @subclass.make_alias(:initialize_dup, :public_one)
+      @subclass.private_instance_methods.include?(:initialize_dup).should be_true
+    end
+
+    it "keeps respond_to_missing? private when aliasing" do
+      @class.make_alias(:respond_to_missing?, :public_one)
+      @class.private_instance_methods.include?(:respond_to_missing?).should be_true
+
+      @subclass.make_alias(:respond_to_missing?, :public_one)
+      @subclass.private_instance_methods.include?(:respond_to_missing?).should be_true
+    end
+  end
+end