如何在 AngularJS 的指令单元测试中注入服务

我需要测试一个对某些注入服务进行调用的指令。 以下代码是一个示例指令，它侦听事件，并在指定元素内按下 Enter 键时重定向浏览器。

Edit: 我感觉我可能正在涉足端到端测试领域？

angular.module('fooApp')
  .directive('gotoOnEnter', ['$location', function ($location) {

    var _linkFn = function link(scope, element, attrs) {

        element.off('keypress').on('keypress', function(e) {
                  if(e.keyCode === 13)
                  {
                       $location.path(scope.redirectUrl);
                  }
              });
    }

    return {
      restrict: 'A',
      link: _linkFn
    };
  }]);

问题是我还没有弄清楚如何在指令中注入服务来监视它们。

我提出的解决方案如下所示：正如预期的那样，它不起作用，因为我没有成功注入$locacion服务成功监视。

describe('Directive: gotoOnEnter', function () {
  beforeEach(module('fooApp'));

  var element;

  it('should visit the link in scope.url when enter is pressed', inject(function ($rootScope, $compile, $location) {

    element = angular.element('<input type="text" goto-on-enter>');
    element = $compile(element)($rootScope);

    $rootScope.redirectUrl = 'http://www.google.com';
    $rootScope.$digest();

    var e = jQuery.Event('keypress');
    e.keyCode = 13;
    element.trigger(e);

    spyOn($location, 'path');

    expect($location.path).toHaveBeenCalledWith('http://www.google.com');
  }));

这产生

Expected spy path to have been called with [ 'http://www.google.com' ] but it was never called.

要装饰、存根、提供模拟或覆盖任何给定的服务，您可以使用$provide服务。$provide.value, $provide.decorator等 文档here https://docs.angularjs.org/api/auto/service/%24provide.

然后你可以做这样的事情：

 var $location;

 beforeEach(function() {
    module('studentportalenApp', function($provide) {
      $provide.decorator('$location', function($delegate) {

        $delegate.path = jasmine.createSpy();

        return $delegate;
      });
    });

    inject(function(_$location_) {
      $location = _$location_;
    });

  });

...

it('should visit the link in scope.redirectUrl when enter is pressed', inject(function ($rootScope, $compile, $location) {
    element = angular.element('<input type="text" goto-on-enter>');
    element = $compile(element)($rootScope);

    $rootScope.redirectUrl = 'http://www.google.com';
    $rootScope.$digest();

    var e = jQuery.Event('keypress');
    e.keyCode = 13;
    element.trigger(e);

    $rootScope.$digest();

    expect($location.path).toHaveBeenCalledWith('http://www.google.com');

}));