Fix reduce problems.

The point to resolve the promise got determined incorrectly.

Author: Sebmaster

SpecRunner.html

@@ -15,6 +15,7 @@
     <script type="text/javascript" src="test/worker.spec.js"></script>
     <script type="text/javascript" src="test/eval.spec.js"></script>
     <script type="text/javascript" src="test/api.spec.js"></script>
+    <script type="text/javascript" src="test/operations.spec.js"></script>
     <script type="text/javascript" src="test/performance.spec.js"></script>
 
     <script type="text/javascript">

lib/parallel.js

@@ -248,12 +248,15 @@
 			throw new Error('Can\'t reduce non-array data');
 		}
 
+		var runningWorkers = 0;
 		var that = this;
 		function done(data) {
-			if (that.data.length === 1) {
+			--runningWorkers;
+			if (that.data.length === 1 && runningWorkers === 0) {
 				that.data = that.data[0];
 				newOp.resolve(null, that.data);
-			} else {
+			} else if (that.data.length > 1) {
+				++runningWorkers;
 				that._spawnReduceWorker([that.data[0], that.data[1]], cb, done);
 				that.data.splice(0, 2);
 			}
@@ -265,6 +268,7 @@
 				newOp.resolve(null, that.data[0]);
 			} else {
 				for (var i = 0; i < that.options.maxWorkers && i < Math.floor(that.data.length / 2); ++i) {
+					++runningWorkers;
 					that._spawnReduceWorker([that.data[i * 2], that.data[i * 2 + 1]], cb, done);
 				}
 

test/operations.spec.js

@@ -0,0 +1,24 @@
+describe('Operations', function () {
+    var isNode = typeof module !== 'undefined' && module.exports;
+    var Parallel = isNode ? require('../lib/parallel.js') : self.Parallel;
+
+    it('should require(), map() and reduce correctly (check console errors)', function () {
+        var p = new Parallel([0, 1, 2, 3, 4, 5, 6, 7, 8]);
+
+        function add(d) { return d[0] + d[1]; }
+        function factorial(n) { return n < 2 ? 1 : n * factorial(n - 1); }
+
+        p.require(factorial);
+
+        var done = false;
+        runs(function () {
+            p.map(function (n) { return Math.pow(10, n); }).reduce(add).then(function() {
+                done = true;
+            });
+        });
+
+        waitsFor(function () {
+            return done;
+        }, "it should finish", 500);
+    });
+});