1 files changed, 11 insertions, 1 deletions
diff --git a/js/codeq/stateMachine.js b/js/codeq/stateMachine.js
index cfb27e7..dff89d5 100644
--- a/js/codeq/stateMachine.js
+++ b/js/codeq/stateMachine.js
@@ -6,8 +6,17 @@ codeq.makeStateMachine = function(def){
     var currState = null;
     return {
         'transition': function(name){
+            var newState = def[name];
+            if (!newState) {
+                codeq.log.error('Cannot transition to state ' + name + ': it is not defined');
+                return;
+            }
+            if (newState === currState) {
+                codeq.log.info('Will not transition between identical states: ' + name);
+                return;
+            }
             if(currState !== null) currState.exit();
-            currState = def[name];
+            currState = newState;
             currState.enter.apply(currState,Array.prototype.slice.apply(arguments,[1]));
         },
         'destroy': function(){
@@ -15,6 +24,7 @@ codeq.makeStateMachine = function(def){
             currState = null;
         },
         'register': function(name,state){
+            if (name in def) codeq.log.error('The state ' + name + ' is already registered, overriding');
             def[name] = state;
         }
     }