Get rid of class vars added to classes including AASM, support inheritance on AASMs

lib/aasm.rb

@@ -11,6 +11,12 @@ module AASM
     base.extend AASM::ClassMethods
     AASM::Persistence.set_persistence(base)
     AASM::StateMachine[base] = AASM::StateMachine.new('')
+
+    base.class_eval do
+      def base.inherited(klass)
+        AASM::StateMachine[klass] = AASM::StateMachine[self].dup
+      end
+    end
   end
 
   module ClassMethods

spec/unit/aasm_spec.rb

@@ -29,8 +29,16 @@ end
 
 class Bar
   include AASM
+
   aasm_state :read
   aasm_state :ended
+
+  aasm_event :foo do
+    transitions :to => :ended, :from => [:read]
+  end
+end
+
+class Baz < Bar
 end
 
 
@@ -251,3 +259,14 @@ describe AASM, '- state actions' do
     foo.close
   end
 end
+
+
+describe Baz do
+  it "should have the same states as it's parent" do
+    Baz.aasm_states.should == Bar.aasm_states
+  end
+
+  it "should have the same events as it's parent" do
+    Baz.aasm_events.should == Bar.aasm_events
+  end
+end