Merge pull request caolan#1320 from caolan/pr/1297

Pr/1297

Author: megawac

lib/internal/filter.js

@@ -10,8 +10,7 @@ export default function _filter(eachfn, arr, iteratee, callback) {
         iteratee(x, function (err, v) {
             if (err) {
                 callback(err);
-            }
-            else {
+            } else {
                 if (v) {
                     results.push({index: index, value: x});
                 }
@@ -21,8 +20,7 @@ export default function _filter(eachfn, arr, iteratee, callback) {
     }, function (err) {
         if (err) {
             callback(err);
-        }
-        else {
+        } else {
             callback(null, arrayMap(results.sort(function (a, b) {
                 return a.index - b.index;
             }), property('value')));

mocha_test/filter.js

@@ -41,6 +41,49 @@ describe("filter", function () {
         });
     });
 
+    it('filter collection', function(done){
+        var a = {a: 3, b: 1, c: 2};
+        async.filter(a, function(x, callback){
+            callback(null, x % 2);
+        }, function(err, results){
+            expect(err).to.equal(null);
+            expect(results).to.eql([3,1]);
+            expect(a).to.eql({a: 3, b: 1, c: 2});
+            done();
+        });
+    });
+
+    if (typeof Symbol === 'function' && Symbol.iterator) {
+        function makeIterator(array){
+            var nextIndex;
+            let iterator = {
+                next: function(){
+                    return nextIndex < array.length ?
+                       {value: array[nextIndex++], done: false} :
+                       {done: true};
+                }
+            };
+            iterator[Symbol.iterator] = function() {
+                nextIndex = 0; // reset iterator
+                return iterator;
+            };
+            return iterator;
+        }
+
+        it('filter iterator', function(done){
+            var a = makeIterator([500, 20, 100]);
+            async.filter(a, function(x, callback) {
+                setTimeout(function() {
+                    callback(null, x > 20);
+                }, x);
+            }, function(err, results){
+                expect(err).to.equal(null);
+                expect(results).to.eql([500, 100]);
+                done();
+            });
+        });
+    }
+
     it('filter error', function(done){
         async.filter([3,1,2], function(x, callback){
             callback('error');