Dispatch state behavior to the superclass if it's undefined for a par…

…ticular state

CHANGELOG.rdoc

@@ -1,5 +1,6 @@
 == master
 
+* Dispatch state behavior to the superclass if it's undefined for a particular state [Sandro Turriate and Tim Pope]
 * Fix state / event names not supporting i18n in ActiveRecord
 * Fix original ActiveRecord::Observer#update not being used for non-state_machine callbacks [Jeremy Wells]
 * Add support for ActiveRecord 3.0

lib/state_machine/state.rb

@@ -168,7 +168,7 @@ def context(&block)
         # Calls the method defined by the current state of the machine
         context.class_eval <<-end_eval, __FILE__, __LINE__
           def #{method}(*args, &block)
-            self.class.state_machine(#{machine_name.inspect}).states.match!(self).call(self, #{method.inspect}, *args, &block)
+            self.class.state_machine(#{machine_name.inspect}).states.match!(self).call(self, #{method.inspect}, lambda {super}, *args, &block)
           end
         end_eval
       end
@@ -185,13 +185,13 @@ def #{method}(*args, &block)
     # 
     # If the method has never been defined for this state, then a NoMethodError
     # will be raised.
-    def call(object, method, *args, &block)
+    def call(object, method, method_missing = nil, *args, &block)
       if context_method = methods[method.to_sym]
         # Method is defined by the state: proxy it through
         context_method.bind(object).call(*args, &block)
       else
-        # Raise exception as if the method never existed on the original object
-        raise NoMethodError, "undefined method '#{method}' for #{object} with #{name || 'nil'} #{machine.name}"
+        # Dispatch to the superclass since this state doesn't handle the method
+        method_missing.call if method_missing
       end
     end
 

test/functional/state_machine_test.rb

@@ -131,6 +131,10 @@ def fix
     auto_shop.fix_vehicle
   end
 
+  def decibels
+    0.0
+  end
+
   private
     # Safety first! Puts on our seatbelt
     def put_on_seatbelt
@@ -169,7 +173,13 @@ class Car < Vehicle
 end
 
 class Motorcycle < Vehicle
-  state_machine :initial => :idling
+  state_machine :initial => :idling do
+    state :first_gear do
+      def decibels
+        1.0
+      end
+    end
+  end
 end
 
 class TrafficLight
@@ -765,6 +775,16 @@ def test_should_not_allow_crash
   def test_should_not_allow_repair
     assert !@motorcycle.repair
   end
+
+  def test_should_inherit_decibels_from_superclass
+    @motorcycle.park
+    assert_equal 0.0, @motorcycle.decibels
+  end
+
+  def test_should_use_decibels_defined_in_state
+    @motorcycle.shift_up
+    assert_equal 1.0, @motorcycle.decibels
+  end
 end
 
 class CarTest < Test::Unit::TestCase

test/unit/state_test.rb

@@ -626,9 +626,8 @@ def speed
     @object = @klass.new
   end
 
-  def test_should_raise_an_exception
-    exception = assert_raise(NoMethodError) { @state.call(@object, :invalid) }
-    assert_equal "undefined method 'invalid' for #{@object} with idling state", exception.message
+  def test_should_call_method_missing_arg
+    assert_equal 1, @state.call(@object, :invalid, lambda {1})
   end
 end
 
@@ -648,19 +647,19 @@ def speed(arg = nil)
   end
 
   def test_should_not_raise_an_exception
-    assert_nothing_raised { @state.call(@object, :speed) }
+    assert_nothing_raised { @state.call(@object, :speed, lambda {raise}) }
   end
 
   def test_should_pass_arguments_through
-    assert_equal 1, @state.call(@object, :speed, 1)
+    assert_equal 1, @state.call(@object, :speed, lambda {}, 1)
   end
 
   def test_should_pass_blocks_through
     assert_equal [nil, 1], @state.call(@object, :speed) {1}
   end
 
   def test_should_pass_both_arguments_and_blocks_through
-    assert_equal [1, 2], @state.call(@object, :speed, 1) {2}
+    assert_equal [1, 2], @state.call(@object, :speed, lambda {}, 1) {2}
   end
 end