在Jasmine中测试try / catch不起作用

Question

我有我要测试的AngularJS中的这段代码：

var _savePendingChanges = function() {
  try {
    $rootScope.$broadcast('externalSave');
  } catch (e) {
    // Sometimes, AngularJS throws a "Cannot read property $$nextSibling of
    // null" error. To get around this we must use $apply().
    $rootScope.$apply(function() {
      $rootScope.$broadcast('externalSave');
    });
  }
}

这里是我到目前为止编写的测试，它无法正常工作（它抛出了errorMessage中的错误和Jasmine错误：Error: Expected function to throw an Error.）：

fit('should save pending changes', function() {
    var errorMessage = 'Cannot read property $$nextSibling of null'; 
    spyOn($rootScope, '$broadcast').and.throwError(errorMessage);
    expect(function() {
      RouterService.savePendingChanges();
    }).toThrowError(errorMessage);
  });

有人可以帮我吗？谢谢！

Answer 1

您可以检查广播是否被两次调用：

fit('should save pending changes', function () {
    var errorMessage = 'Cannot read property $$nextSibling of null';
    var broadcastSpy = spyOn($rootScope, '$broadcast').and.throwError(errorMessage);

    RouterService.savePendingChanges();

    expect(broadcastSpy).toHaveBeenCalledTimes(2);
});