Improve aliasing to object class name

lib/draper/decorator.rb

@@ -16,15 +16,6 @@ module Draper
     # @return [Hash] extra data to be used in user-defined methods.
     attr_accessor :context
 
-    def self.inherited(klass)
-      begin
-        alias_name = klass.name.downcase.gsub(/decorator/, "").to_sym
-        klass.send(:define_method, alias_name) do
-          object
-        end
-      rescue; end
-    end
-
     # Wraps an object in a new instance of the decorator.
     #
     # Decorators may be applied to other decorators. However, applying a
@@ -66,6 +57,7 @@ module Draper
     # @return [void]
     def self.decorates(object_class)
       @object_class = object_class.to_s.camelize.constantize
+      alias_object_to_object_class_name
     end
 
     # Returns the source class corresponding to the decorator class, as set by
@@ -228,6 +220,15 @@ module Draper
 
     private
 
+    def self.inherited(subclass)
+      subclass.alias_object_to_object_class_name
+      super
+    end
+
+    def self.alias_object_to_object_class_name
+      alias_method object_class.name.underscore, :object if object_class?
+    end
+
     def self.object_class_name
       raise NameError if name.nil? || name.demodulize !~ /.+Decorator$/
       name.chomp("Decorator")

spec/draper/decorator_spec.rb

@@ -361,20 +361,43 @@ module Draper
       end
     end
 
-    describe "aliasing object to wrapped model name" do
-      class ::ProductDecorator < Decorator; end
-      class ::Product
-        attr_reader :name
-        def initialize
-          @name = "bob"
+    describe "aliasing object to object class name" do
+      context "when object_class is inferrable from the decorator name" do
+        it "aliases object to the object class name" do
+          object = stub
+          decorator = ProductDecorator.new(object)
+
+          expect(decorator.product).to be object
         end
       end
 
-      it "aliases object to wrapped model name" do
-        decorator = ProductDecorator.new(Product.new)
+      context "when object_class is set by decorates" do
+        it "aliases object to the object class name" do
+          decorator_class = Class.new(Decorator) { decorates Product }
+          object = stub
+          decorator = decorator_class.new(object)
 
-        expect(decorator.product).not_to be nil
-        expect(decorator.product.name).to eq "bob"
+          expect(decorator.product).to be object
+        end
+      end
+
+      context "when object_class's name is several words long" do
+        it "underscores the method name" do
+          stub_const "LongWindedModel", Class.new
+          decorator_class = Class.new(Decorator) { decorates LongWindedModel }
+          object = stub
+          decorator = decorator_class.new(object)
+
+          expect(decorator.long_winded_model).to be object
+        end
+      end
+
+      context "when object_class is not set" do
+        it "does not alias object" do
+          decorator_class = Class.new(Decorator)
+
+          expect(decorator_class.instance_methods).to eq Decorator.instance_methods
+        end
       end
     end