如何在指令中对$ emit进行单元测试？

Question

如何在指令的单元测试中检查是否已调用$ emit？

我的指令相当简单(为了说明的目的):

angular.module('plunker', [])
.directive('uiList', [function () { 
    return {
        scope: {
            lengthModel: '=uiList',
        },
        link: function (scope, elm, attrs) {
            scope.$watch('lengthModel', function (newVal) {
                        scope.$emit('yolo');
            });
        }
    }
}])

所以每次属性uiList改变时,它都会发出事件.

我的单元测试代码如下:

describe('Testing $emit in directive', function() {
  var scope;
  var element;


  //you need to indicate your module in a test
    beforeEach(function () {
        module('plunker');
        inject(function ($rootScope, $compile) {
            scope = $rootScope.$new();
            scope.row= 1;
            spyOn(scope,'$emit');
        element = angular.element('<ul id="rows" ui-list="row">');
        $compile(element)(scope);
        });
    });

  it('should emit', function() {

    scope.$digest();
    scope.row = 2;
    scope.$digest();
    expect(scope.$emit).toHaveBeenCalledWith("yolo");
  });
});

这总是会让我错误地说明范围.$ emit从未被调用过.范围有问题吗？有人可以帮忙吗？

Plunker:http://plnkr.co/edit/AqhPwp？p = preview

Answer 1

你的指令创建了一个独立的范围,它正在调用$emit,所以你需要监视这个范围;)

describe('Testing $emit in directive', function() {
  var scope;
  var element;
  var elementScope;

  beforeEach(module('plunker'));

  beforeEach(inject(function($rootScope, $compile) {
      scope = $rootScope.$new();
      scope.row = 1;
      element = angular.element('<ul id="rows" ui-list="row">');
      $compile(element)(scope);
      scope.$digest();
      elementScope = element.scope();
  }));

  it('should emit', function() {
    // arrange
    spyOn(elementScope, '$emit');

    // act
    scope.$apply(function() {
      scope.row = 2;
    });

    // assert
    expect(elementScope.$emit).toHaveBeenCalledWith("yolo");
  });
});

修复了这里的plunker :)