Don't add named_scope if the ActiveRecord object responds to the method name already (such as 'new')

Signed-off-by: Scott Barron <scott@elitists.net>

lib/persistence/active_record_persistence.rb

@@ -238,7 +238,7 @@ module AASM
       module NamedScopeMethods
         def aasm_state_with_named_scope name, options = {}
           aasm_state_without_named_scope name, options
-          self.named_scope name, :conditions => {self.aasm_column => name.to_s} unless self.scopes.include?(name)
+          self.named_scope name, :conditions => {self.aasm_column => name.to_s} unless self.respond_to?(name)
         end
       end
     end

spec/unit/active_record_persistence_spec.rb

@@ -200,6 +200,25 @@ begin
     end
   end
 
+  describe AASM::Persistence::ActiveRecordPersistence::NamedScopeMethods do
+    class NamedScopeExample < ActiveRecord::Base
+      include AASM
+    end
+
+    context "Does not already respond_to? the scope name" do
+      it "should add a named_scope" do
+        NamedScopeExample.should_receive(:named_scope)
+        NamedScopeExample.aasm_state :unknown_scope
+      end
+    end
+
+    context "Already respond_to? the scope name" do
+      it "should not add a named_scope" do
+        NamedScopeExample.should_not_receive(:named_scope)
+        NamedScopeExample.aasm_state :new
+      end
+    end
+  end
 
   # TODO: figure out how to test ActiveRecord reload! without a database