Error in UI Bootstrap datatpicker

HTML

<body  ng-app="app" ng-controller="AppController">

<form name="form">
        <input name="testDatepicker" 
               ng-model="testDatepicker"
               placeholder="dd/MM/yyyy"
               min-date="minDate"
               is-open="endAlert.opened"
               uib-datepicker-popup="dd/MM/yyyy"/>
         <button type="button" ng-click="openEndAlert()">
         Open
         </button>

        <div style="color:red;font-weight:bold;"
             ng-show="form.testDatepicker.$dirty && form.testDatepicker.$invalid">
           Invalid date
        </div>

</form>

{{ form.testDatepicker | json }}

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular-ui-bootstrap/2.5.0/ui-bootstrap-tpls.js"></script>

<script>
    angular.module('app', ['ui.bootstrap'])
        .controller('AppController', function ($scope) {
            //$scope.testDatepicker = new Date();
            $scope.minDate = new Date();
            
            $scope.openEndAlert = function () {
            	$scope.endAlert.opened = true;
        		}
            
            $scope.endAlert = {
            	opened: false,
            	date: ""
        		}
        });
</script>

</body>