test.js

angular.module('moduleName')
  .controller('TestController', function($scope) {
    $scope.onFileSet = function(file) {
      var reader = new FileReader();
      reader.onload = function(e) {
        $scope.$apply(function() {
          $scope.article.thumbnail.url = e.target.result;
        });
      }
      reader.readAsDataURL(file)
    }
  })


// <div ng-controller="TestController" >
//   <img ng-src="{{article.thumbnail.url}}" alt="" width="125px" height="125px" ng-if="article.thumbnail.url.length">
// </div>