fix(orderBy): compare timestamps when sorting date objects

Fixes #10512
Closes #10516

Author: pkozlowski-opensource

src/ng/filter/orderBy.js

@@ -172,14 +172,14 @@ function orderByFilter($parse) {
 
     function objectToString(value) {
       if (value === null) return 'null';
-      if (typeof value.toString === 'function') {
-        value = value.toString();
-        if (isPrimitive(value)) return value;
-      }
       if (typeof value.valueOf === 'function') {
         value = value.valueOf();
         if (isPrimitive(value)) return value;
       }
+      if (typeof value.toString === 'function') {
+        value = value.toString();
+        if (isPrimitive(value)) return value;
+      }
       return '';
     }
 

test/ng/filter/orderBySpec.js

@@ -79,6 +79,16 @@ describe('Filter: orderBy', function() {
               { a:new Date('01/01/2014'), b:3 }]);
     });
 
+    it('should compare timestamps when sorting dates', function() {
+      expect(orderBy([
+        new Date('01/01/2015'),
+        new Date('01/01/2014')
+      ])).toEqualData([
+        new Date('01/01/2014'),
+        new Date('01/01/2015')
+      ]);
+    });
+
 
     it('should use function', function() {
       expect(