Fix issue jakesgordon#60 - can() with unexpected event (crashes)

jakesgordon · jakesgordon · commit 3d71da4ebccb · 2016-11-18T16:06:10.000-08:00
diff --git a/state-machine.js b/state-machine.js
@@ -76,7 +76,7 @@
 
       fsm.current     = 'none';
       fsm.is          = function(state) { return Array.isArray(state) ? (state.indexOf(this.current) >= 0) : (this.current === state); };
-      fsm.can         = function(event) { return !this.transition && (map[event].hasOwnProperty(this.current) || map[event].hasOwnProperty(StateMachine.WILDCARD)); }
+      fsm.can         = function(event) { return !this.transition && (map[event] !== undefined) && (map[event].hasOwnProperty(this.current) || map[event].hasOwnProperty(StateMachine.WILDCARD)); }
       fsm.cannot      = function(event) { return !this.can(event); };
       fsm.transitions = function()      { return (transitions[this.current] || []).concat(transitions[StateMachine.WILDCARD] || []); };
       fsm.isFinished  = function()      { return this.is(terminal); };
diff --git a/state-machine.min.js b/state-machine.min.js
diff --git a/test/test_basics.js b/test/test_basics.js
@@ -76,6 +76,9 @@ test("can & cannot", function() {
   ok(fsm.cannot('panic'), "should NOT be able to panic from red state")
   ok(fsm.can('calm'),     "should be able to calm from red state")
 
+  equal(fsm.can('jibber'),    false, "unknown event should not crash")
+  equal(fsm.cannot('jabber'), true,  "unknown event should not crash")
+
 });
 
 //-----------------------------------------------------------------------------
