Merge pull request caolan#100 from mmalecki/foreach-no-callback

Allow `forEach*` functions to be called with no callback

lib/async.js

@@ -77,6 +77,7 @@
     }
 
     async.forEach = function (arr, iterator, callback) {
+        callback = callback || function () {};
         if (!arr.length) {
             return callback();
         }
@@ -98,6 +99,7 @@
     };
 
     async.forEachSeries = function (arr, iterator, callback) {
+        callback = callback || function () {};
         if (!arr.length) {
             return callback();
         }
@@ -123,6 +125,7 @@
     };
 
     async.forEachLimit = function (arr, limit, iterator, callback) {
+        callback = callback || function () {};
         if (!arr.length || limit <= 0) {
             return callback(); 
         }

test/test-async.js

@@ -37,6 +37,12 @@ function detectIterator(call_order, x, callback) {
     }, x*25);
 }
 
+function forEachNoCallbackIterator(test, x, callback) {
+    test.equal(x, 1);
+    callback();
+    test.done();
+}
+
 function getFunctionsObject(call_order) {
     return {
         one: function(callback){
@@ -514,6 +520,10 @@ exports['forEach error'] = function(test){
     setTimeout(test.done, 50);
 };
 
+exports['forEach no callback'] = function(test){
+    async.forEach([1], forEachNoCallbackIterator.bind(this, test));
+};
+
 exports['forEachSeries'] = function(test){
     var args = [];
     async.forEachSeries([1,3,2], forEachIterator.bind(this, args), function(err){
@@ -546,6 +556,10 @@ exports['forEachSeries error'] = function(test){
     setTimeout(test.done, 50);
 };
 
+exports['forEachSeries no callback'] = function(test){
+    async.forEachSeries([1], forEachNoCallbackIterator.bind(this, test));
+};
+
 exports['forEachLimit'] = function(test){
     var args = [];
     var arr = [0,1,2,3,4,5,6,7,8,9];
@@ -617,6 +631,10 @@ exports['forEachLimit error'] = function(test){
     setTimeout(test.done, 25);
 };
 
+exports['forEachLimit no callback'] = function(test){
+    async.forEachLimit([1], 1, forEachNoCallbackIterator.bind(this, test));
+};
+
 exports['map'] = function(test){
     var call_order = [];
     async.map([1,3,2], mapIterator.bind(this, call_order), function(err, results){