Initial fixes for Singleton module

adambeynon · adambeynon · commit 99f51d11c65c · 2013-07-30T20:28:04.000+01:00
diff --git a/corelib/opal/runtime.js b/corelib/opal/runtime.js
@@ -296,6 +296,16 @@
     throw Opal.ArgumentError.$new(msg);
   };
 
+  // Super dispatcher
+  Opal.dispatch_super = function(obj, jsid, args) {
+    if (obj._isClass) {
+      return obj._klass['$' + jsid].apply(obj, args);
+    }
+    else {
+      return obj._klass._super._proto['$' + jsid].apply(obj, args);
+    }
+  };
+
   /*
     Call a ruby method on a ruby object with some arguments:
 
diff --git a/lib/opal/parser.rb b/lib/opal/parser.rb
@@ -2107,7 +2107,7 @@ def js_super args, sexp
         if @scope.defs
           [fragment(("%s._super%s.apply(this, " % [cls_name, jsid]), sexp), args, fragment(")", sexp)]
         else
-          [fragment("#{current_self}._klass._super._proto#{jsid}.apply(#{current_self}, ", sexp), args, fragment(")", sexp)]
+          [fragment("__opal.dispatch_super(#{current_self}, #{@scope.mid.to_s.inspect}, ", sexp), args, fragment(")", sexp)]
         end
 
       elsif @scope.type == :iter
diff --git a/spec/rubyspec/library/singleton/clone_spec.rb b/spec/rubyspec/library/singleton/clone_spec.rb
@@ -0,0 +1,8 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Singleton#clone" do
+  it "is prevented" do
+    lambda { SingletonSpecs::MyClass.instance.clone }.should raise_error(TypeError)
+  end
+end
diff --git a/spec/rubyspec/library/singleton/dup_spec.rb b/spec/rubyspec/library/singleton/dup_spec.rb
@@ -0,0 +1,8 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Singleton#dup" do
+  it "is prevented" do
+    lambda { SingletonSpecs::MyClass.instance.dup }.should raise_error(TypeError)
+  end
+end
diff --git a/spec/rubyspec/library/singleton/fixtures/classes.rb b/spec/rubyspec/library/singleton/fixtures/classes.rb
@@ -0,0 +1,18 @@
+require 'singleton'
+
+module SingletonSpecs
+  class MyClass
+    attr_accessor :data
+    include Singleton
+  end
+
+  class NewSpec
+    include Singleton
+  end
+
+  class MyClassChild < MyClass
+  end
+
+  class NotInstantiated < MyClass
+  end
+end
diff --git a/spec/rubyspec/library/singleton/instance_spec.rb b/spec/rubyspec/library/singleton/instance_spec.rb
@@ -0,0 +1,30 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Singleton.instance" do
+  it "returns an instance of the singleton class" do
+    SingletonSpecs::MyClass.instance.should be_kind_of(SingletonSpecs::MyClass)
+  end
+
+  it "returns the same instance for multiple calls to instance" do
+    SingletonSpecs::MyClass.instance.should equal(SingletonSpecs::MyClass.instance)
+  end
+
+  it "returns an instance of the singleton's subclasses" do
+    SingletonSpecs::MyClassChild.instance.should be_kind_of(SingletonSpecs::MyClassChild)
+  end
+
+  it "returns the same instance for multiple class to instance on subclasses" do
+    SingletonSpecs::MyClassChild.instance.should equal(SingletonSpecs::MyClassChild.instance)
+  end
+
+  pending "returns an instance of the singleton's clone" do
+    klone = SingletonSpecs::MyClassChild.clone
+    klone.instance.should be_kind_of(klone)
+  end
+
+  pending "returns the same instance for multiple class to instance on clones" do
+    klone = SingletonSpecs::MyClassChild.clone
+    klone.instance.should equal(klone.instance)
+  end
+end
diff --git a/stdlib/singleton.rb b/stdlib/singleton.rb
@@ -7,21 +7,34 @@ def dup
     raise TypeError, "can't dup instance of singleton #{self.class}"
   end
 
-  def self.included (klass)
-    super
+  module SingletonClassMethods
 
-    class << klass
-      #def new
-        #raise ArgumentError, "you can't call #new on a Singleton" if @instance
-
-        #@instance = super
-      #end
+    def clone
+      Singleton.__init__(super)
+    end
 
-      undef_method :allocate
+    def inherited(sub_klass)
+      super
+      Singleton.__init__(sub_klass)
+    end
+  end
 
-      def instance
-        @instance ||= new()
+  class << Singleton
+    def __init__(klass)
+      klass.instance_eval {
+        @singleton__instance__ = nil
+      }
+      def klass.instance
+        return @singleton__instance__ if @singleton__instance__
+        @singleton__instance__ = new()
       end
+      klass
+    end
+
+    def included(klass)
+      super
+      klass.extend SingletonClassMethods
+      Singleton.__init__(klass)
     end
   end
 end
