Passing event arguments to the guard function

lib/aasm/event.rb

@@ -14,7 +14,7 @@ def fire(obj, to_state=nil, *args)
     next_state = nil
     transitions.each do |transition|
       next if to_state and !Array(transition.to).include?(to_state)
-      if transition.perform(obj)
+      if transition.perform(obj, *args)
         next_state = to_state || Array(transition.to).first
         transition.execute(obj, *args)
         break

lib/aasm/state_transition.rb

@@ -7,12 +7,12 @@ def initialize(opts)
     @opts = opts
   end
 
-  def perform(obj)
+  def perform(obj, *args)
     case @guard
       when Symbol, String
-        obj.send(@guard)
+        obj.send(@guard, *args)
       when Proc
-        @guard.call(obj)
+        @guard.call(obj, *args)
       else
         true
     end

spec/unit/event_spec.rb

@@ -48,6 +48,20 @@ def new_event
 
     event.fire(obj).should == :closed
   end
+
+
+  it 'should call the guard with the params passed in' do
+    event = AASM::SupportingClasses::Event.new(:event) do
+      transitions :to => :closed, :from => [:open, :received], :guard => :guard_fn
+    end
+
+    obj = mock('object')
+    obj.stub!(:aasm_current_state).and_return(:open)
+    obj.should_receive(:guard_fn).with('arg1', 'arg2').and_return(true)
+
+    event.fire(obj, nil, 'arg1', 'arg2').should == :closed
+  end
+
 end
 
 describe AASM::SupportingClasses::Event, 'when executing the success callback' do