AngularJS和Firebase的较新版本，但我仍然得到TypeError：$ cookies.get不是一个函数

Question

(function() {
    function uCtrl($uibModalInstance, $cookies) {

        var saveUser = function(username) {
            $cookies.put('blocChatCurrentUser', 'username');
        };

        var getUser = function() {
            return $cookies.get('blocChatCurrentUser');
        };

        this.isValid = function() {
          var currentUser = getUser();
          if(!currentUser === undefined) {
              currentUser = currentUser.replace(/^\s+/, '').replace(/\s+$/, '');
          }
          else if(currentUser === '' || currentUser === undefined) {
              this.currentUserError = 'Username Cannot Be Empty';
              this.currentUserErrorTrue = true;
              this.setUsername.name = '';
              return;
          }
          else {
              $cookies.blocChatCurrentUser = currentUser;
              saveUser(currentUser);
              $uibModalInstance.dismiss();
          }
        };
    }

    angular
        .module('blocChat')
        .controller('uCtrl', ['$cookies', '$uibModalInstance', uCtrl]);
})();

<div>
    <div class = "modal-header">
        <h2 class = "modal-title">Set A Username</h2>
    </div>
    <div class = "modal-body">
        <br>This name will appear when you send messages.</br>
        <form name = "Username" ng-submit = "cookieThis.isValid()">
            <div class = "input-group animated">
                <input type = "text" class = "form-control finderBar" ng-model = "this.username" name = "username" ng-minlength = "1" required autofocus>
            </div>
        </form>
    </div>
    <div class = "modal-footer">
      <button class="btn btn-primary" type="button" ng-click= "cookieThis.isValid()" ng-disabled = "this.username == null">Set Username</button>
    </div>
</div>

所有其他文件都可以正常工作。 ModalInstanceCtrl和ModalCtrl都已经使用各自的.html文件进行了测试，并且可以正常工作。所以基本上，我试图获取用户提供的用户名并将其存储在cookie中。当然，有使用cookie的getUser（）和setUser（）方法。