单元测试angular引导模态服务

我创建了一个通用的ModalService，它用于两种不同类型的对话框。CancelDialog和ErrorDialog将根据传递给服务的参数弹出。

当功能正常工作时，我们为什么要进行单元测试?

。e这将显示一个ErrorDialog

ModalService.openModal('Analysis Error', 'I am Error Type', 'Error');

一切都很好，但我坚持单元测试。这是正在工作的PLUNKER。请帮忙覆盖单元测试。

如何为openErrorModal &openCancelModal在以下服务

ModalService

// common modal service
validationApp.service('ModalService',
  function($uibModal) {
    return {
      openModal: openModal
    };
    function openErrorModal(title, message, callback) {
      $uibModal.open({
        templateUrl: 'ErrorDialog.html',
        controller: 'ErrorDialogCtrl',
        controllerAs: 'vm',
        backdrop: 'static',
        size: 'md',
        resolve: {
          message: function() {
            return message;
          },
          title: function() {
            return title;
          },
          callback: function() {
            return callback;
          }
        }
      });
    }
    function openCancelModal(title, message, callback) {
      $uibModal.open({
        templateUrl: 'CancelDialog.html',
        controller: 'ErrorDialogCtrl',
        controllerAs: 'vm',
        backdrop: 'static',
        size: 'md',
        resolve: {
          message: function() {
            return message;
          },
          title: function() {
            return title;
          },
          callback: function() {
            return callback;
          }
        }
      });
    }
    function openModal(title, message, modalType, callback) {
      if (modalType === "Error") {
        openErrorModal(title, message, callback);
      } else {
        openCancelModal(title, message, callback);
      }
    }
  }
);

如何单元测试onOk, onContinue &onDiscard在以下控制器

DialogController

//controller fot dialog
validationApp.controller('ErrorDialogCtrl',
  function($uibModalInstance, message, title, callback) {
    alert('from controller');
    var vm = this;
    vm.message = message;
    vm.onOk = onOk;
    vm.onContinue = onContinue;
    vm.onDiscard = onDiscard;
    vm.callback = callback;
    vm.title = title;
    function onOk() {
      $uibModalInstance.close();
    }
    function onContinue() {
      $uibModalInstance.close();
    }
    function onDiscard() {
      vm.callback();
      $uibModalInstance.close();
    }
  });