Merge pull request #311 from flightjs/get_enumerable_property

Get enumerable property
flightjs · Sep 16, 2014 · 72d73d9 · 72d73d9
2 parents 6958b42 + e954ef3
commit 72d73d9
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Showing 3 changed files with 31 additions and 9 deletions.
diff --git a/doc/utils_api.md b/doc/utils_api.md
@@ -40,10 +40,11 @@ The handlers are lazily resolved when the event is fired.
 
 Detect if an object is a DOM node.
 
-<a name="utils.isEnumerable"></a>
-## utils.isEnumerable(obj, property)
+<a name="utils.getEnumerableProperty"></a>
+## utils.getEnumerableProperty(obj, key)
 
-Detect is a property of an object is enumerable.
+If obj.key points to an enumerable property, return its value
+If obj.key points to a non-enumerable property, return undefined
 
 <a name="utils.merge"></a>
 ## utils.merge(obj1, obj2, ... [, deepClone])

diff --git a/lib/utils.js b/lib/utils.js
@@ -10,7 +10,7 @@ define(
     var DEFAULT_INTERVAL = 100;
 
     function canWriteProtect() {
-      var writeProtectSupported = debug.enabled && !utils.isEnumerable(Object, 'getOwnPropertyDescriptor');
+      var writeProtectSupported = debug.enabled && !Object.propertyIsEnumerable('getOwnPropertyDescriptor');
       if (writeProtectSupported) {
         //IE8 getOwnPropertyDescriptor is built-in but throws exeption on non DOM objects
         try {
@@ -123,8 +123,10 @@ define(
         return base;
       },
 
-      isEnumerable: function(obj, property) {
-        return Object.keys(obj).indexOf(property) > -1;
+      // If obj.key points to an enumerable property, return its value
+      // If obj.key points to a non-enumerable property, return undefined
+      getEnumerableProperty: function(obj, key) {
+        return obj.propertyIsEnumerable(key) ? obj[key] : undefined;
       },
 
       // build a function from other function(s)

diff --git a/test/spec/utils_spec.js b/test/spec/utils_spec.js
@@ -317,8 +317,6 @@ define(['lib/component', 'lib/utils', 'lib/debug'], function (defineComponent, u
       expect(spy1).toHaveBeenCalled();
       expect(spy2).not.toHaveBeenCalled();
     });
-
-
   });
 
   describe('countThen()', function () {
@@ -359,7 +357,7 @@ define(['lib/component', 'lib/utils', 'lib/debug'], function (defineComponent, u
     });
   });
 
-    describe('property locking', function() {
+  describe('property locking', function() {
     beforeEach(function () {
       debug.enable(true);
     });
@@ -402,4 +400,25 @@ define(['lib/component', 'lib/utils', 'lib/debug'], function (defineComponent, u
       });
     });
   });
+
+  describe('getEnumerableProperty()', function() {
+    var obj;
+
+    beforeEach(function () {
+      obj = {
+        custom: 123
+      };
+    });
+
+    it('should return custom values', function() {
+      expect(utils.getEnumerableProperty(obj, 'custom')).toBe(123);
+    });
+    it('should not return native values', function() {
+      expect(utils.getEnumerableProperty(obj, 'toString')).toBe(undefined);
+    });
+    it('should return shadowed native values', function() {
+      obj.toString = function() {};
+      expect(typeof utils.getEnumerableProperty(obj, 'toString')).toBe('function');
+    });
+  });
 });