Handle options properly in Decoratable#decorate

In 30104b0 I had accidentally nuked the options but didn't realise
as there was no spec coverage.

I then discovered that, due to memoization, `#decorate` did not
use options after the first call:

    product.decorate(role: :admin)
    product.decorate(role: :user)  # still has admin role!

I ditched the `#decorator` alias since `#decorate` seems far more
canonical, and dropped the block passing syntax, since this seems
orthogonal to the main purpose of the method.

lib/draper/decoratable.rb

@@ -1,11 +1,9 @@
 module Draper::Decoratable
   extend ActiveSupport::Concern
 
-  def decorator(options = {})
+  def decorate(options = {})
-    @decorator ||= decorator_class.decorate(self)
+    decorator_class.decorate(self, options)
-    block_given? ? yield(@decorator) : @decorator
   end
-  alias_method :decorate, :decorator
 
   def decorator_class
     self.class.decorator_class
@@ -25,8 +23,7 @@ module Draper::Decoratable
 
   module ClassMethods
     def decorate(options = {})
-      collection_decorator = decorator_class.decorate_collection(self.scoped, options)
+      decorator_class.decorate_collection(self.scoped, options)
-      block_given? ? yield(collection_decorator) : collection_decorator
     end
 
     def decorator_class

spec/draper/decoratable_spec.rb

@@ -3,17 +3,19 @@ require 'spec_helper'
 describe Draper::Decoratable do
   subject { Product.new }
 
-  describe '#decorator' do
+  describe "#decorate" do
-    its(:decorator) { should be_kind_of(ProductDecorator) }
+    it "returns a decorator for self" do
-    its(:decorator) { should be(subject.decorator) }
+     subject.decorate.should be_a ProductDecorator
+     subject.decorate.source.should be subject
+   end
 
-    it 'have abillity to pass block' do
+    it "accepts options" do
-      a = Product.new.decorator { |d| d.awesome_title }
+      decorator = subject.decorate(some: "options")
-      a.should eql "Awesome Title"
+      decorator.options.should == {some: "options"}
     end
 
-    it 'is aliased to .decorate' do
+    it "is not memoized" do
-      subject.decorator.model.should == subject.decorate.model
+      subject.decorate.should_not be subject.decorate
     end
   end
 
@@ -43,6 +45,27 @@ describe Draper::Decoratable do
     end
   end
 
+  describe ".decorate" do
+    it "returns a collection decorator" do
+      Product.stub(:scoped).and_return([Product.new])
+      Product.stub(:decorator_class).and_return(WidgetDecorator)
+      decorator = Product.decorate
+
+      decorator.should be_a Draper::CollectionDecorator
+      decorator.decorator_class.should be WidgetDecorator
+      decorator.source.should be Product.scoped
+    end
+
+    it "accepts options" do
+      decorator = Product.decorate(some: "options")
+      decorator.options.should == {some: "options"}
+    end
+
+    it "is not memoized" do
+      Product.decorate.should_not be Product.decorate
+    end
+  end
+
   describe ".decorator_class" do
     context "for non-ActiveModel classes" do
       it "infers the decorator from the class" do
@@ -57,39 +80,16 @@ describe Draper::Decoratable do
       end
     end
 
+    context "for namespaced ActiveModel classes" do
+      it "infers the decorator from the model name" do
+        Namespace::Product.decorator_class.should be Namespace::ProductDecorator
+      end
+    end
+
     context "when the decorator can't be inferred" do
       it "throws an UninferrableDecoratorError" do
         expect{UninferrableDecoratorModel.decorator_class}.to raise_error Draper::UninferrableDecoratorError
       end
     end
   end
-
-  describe Draper::Decoratable::ClassMethods do
-    shared_examples_for "a call to Draper::Decoratable::ClassMethods#decorate" do
-      subject { klass.limit }
-
-      its(:decorate) { should be_kind_of(Draper::CollectionDecorator) }
-
-      it "decorate the collection" do
-        subject.decorate.size.should == 1
-        subject.decorate.to_ary[0].model.should be_a(klass)
-      end
-
-      it "return a new instance each time it is called" do
-        subject.decorate.should_not == subject.decorate
-      end
-    end
-
-    describe '#decorate - decorate collections of AR objects' do
-      let(:klass) { Product }
-
-      it_should_behave_like "a call to Draper::Decoratable::ClassMethods#decorate"
-    end
-
-    describe '#decorate - decorate collections of namespaced AR objects' do
-      let(:klass) { Namespace::Product }
-
-      it_should_behave_like "a call to Draper::Decoratable::ClassMethods#decorate"
-    end
-  end
 end