Fix issue 26

Do not cache subscribers.length when publishing topics, as subscribers might change this by subscribing or unsubscribing.

src/pubsub.js

@@ -70,7 +70,10 @@ https://github.com/mroderick/PubSubJS
 			return;
 		}
 
-		for ( i = 0, j = subscribers.length; i < j; i++ ){
+		// do not cache the length of the subscribers array, as it might change if there are unsubscribtions
+		// by subscribers during delivery of a topic
+		// see https://github.com/mroderick/PubSubJS/issues/26
+		for ( i = 0; i < subscribers.length; i++ ){
 			callSubscriber( subscribers[i].func, originalMessage, data );
 		}
 	}

test/test-unsubscribe.js

@@ -1,14 +1,15 @@
-/*jslint white:true*/
+/*jslint white:true, stupid:true*/
 /*global
 	PubSub,
 	buster,
 	assert,
+	refute,
 	require,
 	sinon
 */
 (function( global ){
 	"use strict";
-	
+
 	var PubSub = global.PubSub || require("../src/pubsub"),
 		TestHelper = global.TestHelper || require("../test/helper");
 
@@ -19,8 +20,8 @@
 				message = TestHelper.getUniqueString(),
 				token = PubSub.subscribe( message, func),
 				result = PubSub.unsubscribe( token );
-				
-			assert.equals( result, token );		   
+
+			assert.equals( result, token );
 		},
 
 		"should return false when unsuccesful" : function(){
@@ -35,9 +36,9 @@
 
 			// now let's try unsubscribing the same method twice
 			PubSub.unsubscribe( token );
-			assert.equals( PubSub.unsubscribe( token ), false );		
+			assert.equals( PubSub.unsubscribe( token ), false );
 		},
-		
+
 
 		"with function argument should return true when succesful" : function(){
 			var func = function(){},
@@ -47,7 +48,7 @@
 			PubSub.subscribe( message, func);
 			result = PubSub.unsubscribe( func );
 
-			assert.equals( result, true );        
+			assert.equals( result, true );
 		},
 
 		"with function argument should return false when unsuccesful" : function(){
@@ -69,9 +70,23 @@
 			PubSub.unsubscribe( func );
 
 			// unsubscribe again
-			assert.equals( PubSub.unsubscribe( func ), false );        
-		 }		
+			assert.equals( PubSub.unsubscribe( func ), false );
+		},
+
+		'must not throw exception when unsubscribing as part of publishing' : function(){
+			refute.exception(function(){
+				var topic = TestHelper.getUniqueString(),
+					sub1 = function(){
+						PubSub.unsubscribe(sub1);
+					},
+					sub2 = function(){};
+
+				PubSub.subscribe( topic, sub1 );
+				PubSub.subscribe( topic, sub2 );
 
+				PubSub.publishSync( topic, 'hello world!' );
+			});
+		}
 	});
 
 }(this));