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-rw-r--r--spec/ruby/language/singleton_class_spec.rb293
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diff --git a/spec/ruby/language/singleton_class_spec.rb b/spec/ruby/language/singleton_class_spec.rb
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+require File.expand_path('../../spec_helper', __FILE__)
+require File.expand_path('../../fixtures/class', __FILE__)
+
+describe "A singleton class" do
+ it "is TrueClass for true" do
+ true.singleton_class.should == TrueClass
+ end
+
+ it "is FalseClass for false" do
+ false.singleton_class.should == FalseClass
+ end
+
+ it "is NilClass for nil" do
+ nil.singleton_class.should == NilClass
+ end
+
+ it "raises a TypeError for Fixnum's" do
+ lambda { 1.singleton_class }.should raise_error(TypeError)
+ end
+
+ it "raises a TypeError for symbols" do
+ lambda { :symbol.singleton_class }.should raise_error(TypeError)
+ end
+
+ it "is a singleton Class instance" do
+ o = mock('x')
+ o.singleton_class.should be_kind_of(Class)
+ o.singleton_class.should_not equal(Object)
+ o.should be_kind_of(o.singleton_class)
+ end
+
+ it "is a Class for classes" do
+ ClassSpecs::A.singleton_class.should be_kind_of(Class)
+ end
+
+ it "inherits from Class for classes" do
+ Class.should be_ancestor_of(Object.singleton_class)
+ end
+
+ it "is a subclass of Class's singleton class" do
+ ec = ClassSpecs::A.singleton_class
+ ec.should be_kind_of(Class.singleton_class)
+ end
+
+ it "is a subclass of the same level of Class's singleton class" do
+ ecec = ClassSpecs::A.singleton_class.singleton_class
+ class_ec = Class.singleton_class
+
+ ecec.should be_kind_of(class_ec.singleton_class)
+ ecec.should be_kind_of(class_ec)
+ end
+
+ it "is a subclass of a superclass's singleton class" do
+ ClassSpecs::K.singleton_class.superclass.should ==
+ ClassSpecs::H.singleton_class
+ end
+
+ it "is a subclass of the same level of superclass's singleton class" do
+ ClassSpecs::K.singleton_class.singleton_class.superclass.should ==
+ ClassSpecs::H.singleton_class.singleton_class
+ end
+
+ it "for BasicObject has Class as it's superclass" do
+ BasicObject.singleton_class.superclass.should == Class
+ end
+
+ it "for BasicObject has the proper level of superclass for Class" do
+ BasicObject.singleton_class.singleton_class.superclass.should ==
+ Class.singleton_class
+ end
+
+ it "has class String as the superclass of a String instance" do
+ "blah".singleton_class.superclass.should == String
+ end
+
+ it "doesn't have singleton class" do
+ lambda { bignum_value.singleton_class.superclass.should == Bignum }.should raise_error(TypeError)
+ end
+end
+
+describe "A constant on a singleton class" do
+ before :each do
+ @object = Object.new
+ class << @object
+ CONST = self
+ end
+ end
+
+ it "can be accessed after the singleton class body is reopened" do
+ class << @object
+ CONST.should == self
+ end
+ end
+
+ it "can be accessed via self::CONST" do
+ class << @object
+ self::CONST.should == self
+ end
+ end
+
+ it "can be accessed via const_get" do
+ class << @object
+ const_get(:CONST).should == self
+ end
+ end
+
+ it "is not defined on the object's class" do
+ @object.class.const_defined?(:CONST).should be_false
+ end
+
+ it "is not defined in the singleton class opener's scope" do
+ class << @object
+ CONST
+ end
+ lambda { CONST }.should raise_error(NameError)
+ end
+
+ it "cannot be accessed via object::CONST" do
+ lambda do
+ @object::CONST
+ end.should raise_error(TypeError)
+ end
+
+ it "raises a NameError for anonymous_module::CONST" do
+ @object = Class.new
+ class << @object
+ CONST = 100
+ end
+
+ lambda do
+ @object::CONST
+ end.should raise_error(NameError)
+ end
+
+ it "appears in the singleton class constant list" do
+ @object.singleton_class.should have_constant(:CONST)
+ end
+
+ it "does not appear in the object's class constant list" do
+ @object.class.should_not have_constant(:CONST)
+ end
+
+ it "is not preserved when the object is duped" do
+ @object = @object.dup
+
+ lambda do
+ class << @object; CONST; end
+ end.should raise_error(NameError)
+ end
+
+ it "is preserved when the object is cloned" do
+ @object = @object.clone
+
+ class << @object
+ CONST.should_not be_nil
+ end
+ end
+end
+
+describe "Defining instance methods on a singleton class" do
+ before :each do
+ @k = ClassSpecs::K.new
+ class << @k
+ def singleton_method; 1 end
+ end
+
+ @k_sc = @k.singleton_class
+ end
+
+ it "defines public methods" do
+ @k_sc.should have_public_instance_method(:singleton_method)
+ end
+end
+
+describe "Instance methods of a singleton class" do
+ before :each do
+ k = ClassSpecs::K.new
+ @k_sc = k.singleton_class
+ @a_sc = ClassSpecs::A.new.singleton_class
+ @a_c_sc = ClassSpecs::A.singleton_class
+ end
+
+ it "include ones of the object's class" do
+ @k_sc.should have_instance_method(:example_instance_method)
+ end
+
+ it "does not include class methods of the object's class" do
+ @k_sc.should_not have_instance_method(:example_class_method)
+ end
+
+ it "include instance methods of Object" do
+ @a_sc.should have_instance_method(:example_instance_method_of_object)
+ end
+
+ it "does not include class methods of Object" do
+ @a_sc.should_not have_instance_method(:example_class_method_of_object)
+ end
+
+ describe "for a class" do
+ it "include instance methods of Class" do
+ @a_c_sc.should have_instance_method(:example_instance_method_of_class)
+ end
+
+ it "does not include class methods of Class" do
+ @a_c_sc.should_not have_instance_method(:example_class_method_of_class)
+ end
+
+ it "does not include instance methods of the singleton class of Class" do
+ @a_c_sc.should_not have_instance_method(:example_instance_method_of_singleton_class)
+ end
+
+ it "does not include class methods of the singleton class of Class" do
+ @a_c_sc.should_not have_instance_method(:example_class_method_of_singleton_class)
+ end
+ end
+
+ describe "for a singleton class" do
+ it "includes instance methods of the singleton class of Class" do
+ @a_c_sc.singleton_class.should have_instance_method(:example_instance_method_of_singleton_class)
+ end
+
+ it "does not include class methods of the singleton class of Class" do
+ @a_c_sc.singleton_class.should_not have_instance_method(:example_class_method_of_singleton_class)
+ end
+ end
+end
+
+describe "Class methods of a singleton class" do
+ before :each do
+ k = ClassSpecs::K.new
+ @k_sc = k.singleton_class
+ @a_sc = ClassSpecs::A.new.singleton_class
+ @a_c_sc = ClassSpecs::A.singleton_class
+ end
+
+ it "include ones of the object's class" do
+ @k_sc.should have_method(:example_class_method)
+ end
+
+ it "does not include instance methods of the object's class" do
+ @k_sc.should_not have_method(:example_instance_method)
+ end
+
+ it "include instance methods of Class" do
+ @a_sc.should have_method(:example_instance_method_of_class)
+ end
+
+ it "does not include class methods of Class" do
+ @a_sc.should_not have_method(:example_class_method_of_class)
+ end
+
+ describe "for a class" do
+ it "include instance methods of Class" do
+ @a_c_sc.should have_method(:example_instance_method_of_class)
+ end
+
+ it "include class methods of Class" do
+ @a_c_sc.should have_method(:example_class_method_of_class)
+ end
+
+ it "include instance methods of the singleton class of Class" do
+ @a_c_sc.should have_method(:example_instance_method_of_singleton_class)
+ end
+
+ it "does not include class methods of the singleton class of Class" do
+ @a_c_sc.should_not have_method(:example_class_method_of_singleton_class)
+ end
+ end
+
+ describe "for a singleton class" do
+ it "include instance methods of the singleton class of Class" do
+ @a_c_sc.singleton_class.should have_method(:example_instance_method_of_singleton_class)
+ end
+
+ it "include class methods of the singleton class of Class" do
+ @a_c_sc.singleton_class.should have_method(:example_class_method_of_singleton_class)
+ end
+ end
+end
+
+describe "Instantiating a singleton class" do
+ it "raises a TypeError when new is called" do
+ lambda {
+ Object.new.singleton_class.new
+ }.should raise_error(TypeError)
+ end
+
+ it "raises a TypeError when allocate is called" do
+ lambda {
+ Object.new.singleton_class.allocate
+ }.should raise_error(TypeError)
+ end
+end
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