feat(rating): add rounding logic to rating value

- Moved rounding logic into a formatter
- Checking for number instead of checking if undefined
- Using angular.isNumber for rounding logic
- Using bitwise instead of modulo to check for decimel

Fixes #3413
Closes #3415

src/rating/rating.js

@@ -13,6 +13,13 @@ angular.module('ui.bootstrap.rating', [])
     ngModelCtrl = ngModelCtrl_;
     ngModelCtrl.$render = this.render;
 
+    ngModelCtrl.$formatters.push(function(value) {
+      if (angular.isNumber(value) && value << 0 !== value) {
+        value = Math.round(value);
+      }
+      return value;
+    });
+
     this.stateOn = angular.isDefined($attrs.stateOn) ? $scope.$parent.$eval($attrs.stateOn) : ratingConfig.stateOn;
     this.stateOff = angular.isDefined($attrs.stateOff) ? $scope.$parent.$eval($attrs.stateOff) : ratingConfig.stateOff;
 

src/rating/test/rating.spec.js

@@ -73,6 +73,20 @@ describe('rating directive', function () {
     expect($rootScope.rate).toBe(3);
   });
 
+  it('rounds off the number of stars shown with decimal values', function() {
+    $rootScope.rate = 2.1;
+    $rootScope.$digest();
+
+    expect(getState()).toEqual([true, true, false, false, false]);
+    expect(element.attr('aria-valuenow')).toBe('2');
+
+    $rootScope.rate = 2.5;
+    $rootScope.$digest();
+
+    expect(getState()).toEqual([true, true, true, false, false]);
+    expect(element.attr('aria-valuenow')).toBe('3');
+  });
+
   it('changes the number of selected icons when value changes', function() {
     $rootScope.rate = 2;
     $rootScope.$digest();