Add millisecond support for date filter

Date filter should translate input which is a number (or number
string) into a date.

Author: IgorMinar

src/filters.js

@@ -73,9 +73,19 @@ var DATE_FORMATS = {
         }
 };
 var DATE_FORMATS_SPLIT = /([^yMdHhmsaZ]*)(y+|M+|d+|H+|h+|m+|s+|a|Z)(.*)/;
+var NUMBER_STRING = /^\d+$/;
 
 angularFilter.date = function(date, format) {
-  if (!(date instanceof Date)) return date;
+  if (isString(date) && NUMBER_STRING.test(date)) {
+    date = parseInt(date, 10);
+  }
+
+  if (isNumber(date)) {
+    date = new Date(date);
+  } else if (!(date instanceof Date)) {
+    return date;
+  }
+
   var text = date.toLocaleDateString(), fn;
   if (format && isString(format)) {
     text = '';

test/FiltersSpec.js

@@ -98,19 +98,23 @@ describe('filter', function(){
     morning.getTimezoneOffset =
       noon.getTimezoneOffset =
         midnight.getTimezoneOffset =
-          function() { return 7 * 60; };
+          function() {return 7 * 60;};
 
     it('should ignore falsy inputs', function() {
       expect(filter.date(null)).toEqual(null);
       expect(filter.date('')).toEqual('');
-      expect(filter.date(123)).toEqual(123);
     });
 
     it('should do basic filter', function() {
       expect(filter.date(noon)).toEqual(noon.toLocaleDateString());
       expect(filter.date(noon, '')).toEqual(noon.toLocaleDateString());
     });
 
+    it('should accept number or number string representing milliseconds as input', function() {
+      expect(filter.date(noon.getTime())).toEqual(noon.toLocaleDateString());
+      expect(filter.date(noon.getTime() + "")).toEqual(noon.toLocaleDateString());
+    });
+
     it('should accept format', function() {
       expect(filter.date(midnight, "yyyy-M-d h=H:m:saZ")).
                            toEqual('2010-9-3 12=0:5:8am0700');
@@ -122,8 +126,6 @@ describe('filter', function(){
                        toEqual('2010-09-03 12=12:05:08pm0700');
 
     });
-
-
   });
 });