AngularJS 1.6.x FileReader directive for async file uploading

file-reader.js

(function () {
  'use strict';

  var utils = angular.module('utils');

  utils.directive('fileReader', function (EVENTS) {
    return {
      restrict: 'A',

      scope: {
        fileReader: '='
      },

      link: function (scope, element) {
        element.bind('change', function (changeEvent) {
          var reader = new FileReader();

          reader.onload = function (loadEvent) {
            scope.$apply(function () {
              scope.fileReader = dataURItoBlob(loadEvent.target.result);
            });
          };

          reader.readAsArrayBuffer(changeEvent.target.files[0]);
        });

        /**
         * Convert arrayBuffer to raw binary data held in a string
         * @param {ArrayBuffer} fileArrayBuffer - Array buffer which contains file
         * @return {Blob} converted file to blob
         */
        function dataURItoBlob(fileArrayBuffer) {
          var bytesArray = new Uint8Array(fileArrayBuffer);

          return new Blob([bytesArray]);
        }

        scope.$on(EVENTS.FILE_READER.RESET, function () {
          element.val('');

          scope.fileReader = null;
        });
      }
    };
  });
})();

file-reader.spec.js

(function () {
  'use strict';

  describe('Test suite for file-reader directive', function () {
    beforeEach(function () {
      angular.mock.module('utils');
    });

    var $rootScope,
      $compile,
      $scope,
      element;

    beforeEach(inject(function (_$rootScope_,
                                _$compile_) {
      $rootScope = _$rootScope_;

      $scope = $rootScope.$new();

      $compile = _$compile_;
    }));

    beforeEach(function () {
      var html = '<input data-file-reader="someElement"></input>';

      element = $compile(angular.element(html))($scope);

      $rootScope.$digest();
    });

    it('should be correctly compiled', function () {
      expect(element).toBeTruthy();
    });
  });
})();