supporting event inspection for to-states transitions (Event#transitions_to_state?)

CHANGELOG.md

@@ -1,24 +1,28 @@
 # CHANGELOG
 
+## 3.0.14
+
+ * supporting event inspection for to-states transitions (`Event#transitions_to_state?`)
+
 ## 3.0.13
 
- * supporting ActiveRecord transactions when firing an event
+ * supporting *ActiveRecord* transactions when firing an event
 
 ## 3.0.12
 
- * aasm_from_states_for_state now supports to filter for specific transition
+ * `aasm_from_states_for_state` now supports to filter for specific transition
 
 ## 3.0.11
 
- * added class method aasm_from_states_for_state to retrieve all from states (regarding transitions) for a given state
+ * added class method `aasm_from_states_for_state` to retrieve all from states (regarding transitions) for a given state
 
 ## 3.0.10
 
- * added support for transitions from all other states (thanks to Stefan 'swrobel' Wrobel)
+ * added support for transitions from all other states (thanks to *Stefan 'swrobel' Wrobel*)
 
 ## 3.0.9
 
- * guard checks (e.g. may_edit?) now support guard parameters as well
+ * guard checks (e.g. `may_edit?`) now support guard parameters as well
 
 ## 3.0.8
 
@@ -58,7 +62,7 @@
  * whiny transactions: by default, raise an exception if an event transition is not possible
  * you may disable whiny transactions
 
-## 2.4.0 
+## 2.4.0
 
  * supporting new DSL (which is much shorter)
 

lib/aasm/supporting_classes/event.rb

@@ -21,13 +21,17 @@ module AASM
       end
 
       def transitions_from_state?(state)
-        @transitions.any? { |t| t.from == state }
+        transitions_from_state(state).any?
       end
 
       def transitions_from_state(state)
         @transitions.select { |t| t.from == state }
       end
 
+      def transitions_to_state?(state)
+        transitions_to_state(state).any?
+      end
+
       def transitions_to_state(state)
         @transitions.select { |t| t.to == state }
       end

spec/unit/event_spec.rb

@@ -25,6 +25,30 @@ describe 'adding an event' do
   end
 end
 
+describe 'transition inspection' do
+  before do
+    @event = AASM::SupportingClasses::Event.new(:run) do
+      transitions :to => :running, :from => :sleeping
+    end
+  end
+
+  it 'should support inspecting transitions from states' do
+    @event.transitions_from_state(:sleeping).map(&:to).should == [:running]
+    @event.transitions_from_state?(:sleeping).should be_true
+
+    @event.transitions_from_state(:cleaning).map(&:to).should == []
+    @event.transitions_from_state?(:cleaning).should be_false
+  end
+
+  it 'should support inspecting transitions to states' do
+    @event.transitions_to_state(:running).map(&:from).should == [:sleeping]
+    @event.transitions_to_state?(:running).should be_true
+
+    @event.transitions_to_state(:cleaning).map(&:to).should == []
+    @event.transitions_to_state?(:cleaning).should be_false
+  end
+end
+
 describe 'firing an event' do
   it 'should return nil if the transitions are empty' do
     obj = mock('object')