Adds a #persisted? method to the Stub object to conform to the

ActiveModel API

Closes #145

lib/factory_girl/proxy/stub.rb

@@ -7,6 +7,10 @@ module FactoryGirl
         @instance = klass.new
         @instance.id = next_id
         @instance.instance_eval do
+          def persisted?
+            !new_record?
+          end
+
           def new_record?
             id.nil?
           end

spec/factory_girl/proxy/stub_spec.rb

@@ -16,6 +16,10 @@ describe FactoryGirl::Proxy::Stub do
     @stub.result(nil).should_not be_new_record
   end
 
+  it "should be persisted" do
+    @stub.result(nil).should be_persisted
+  end
+
   it "should not be able to connect to the database" do
     lambda { @stub.result(nil).reload }.should raise_error(RuntimeError)
   end