如何重置茉莉花测试淘汰赛绑定

问题描述

我试着写茉莉花测试敲开特征如下，我收到以下错误：

I'm trying to write test for knockout feature with jasmine as below and I'm getting following error:

的错误：你不能多次申请绑定到相同的元素的

describe("ThreeStepNavigationView", ()=> {
    var testSubject;
    var SmallNavigationStates = ['ribbon','expanded'];
    var ExtraSmallNavigationStates = ['collapsed','ribbon','expanded'];
    beforeEach(()=> {
        loadFixtures('SidebarAndSiteHeader.html');
        testSubject = new Mobile.Navigation.ThreeStepNavigation.View();
        ko.applyBindings(testSubject);
    });
    describe('When user clicks on navigation toggle button', ()=>{

    it('Should update state class name to the next state', ()=>{
        var button = $('#MobileMainNavLink');
        var currentScreenSize = Mobile.Helpers.getScreenSize();

        button.click();

        var classValue = $("#sidebar-wrapper").attr('class');
        if (currentScreenSize == 'ExtraSmall') {
            expect(classValue).toBe(ExtraSmallNavigationStates[1]);
        }
        if (currentScreenSize == 'Small') {
            expect(classValue).toBe(SmallNavigationStates[1]);
        }

    });

});

我也尝试重新阁作为，但结果是一样的。

I did try resetting ko as but the result is the same.

 afterEach(()=>{
        ko.cleanNode($('#MobileMainNavLink')[0]);
        ko.cleanNode($('#sidebar-wrapper')[0]);
    });

基于柯文档cleanNode

是一个内部的功能，而不是API的一部分。

Based on ko documentation cleanNode is an internal function and is not part of the API.

我使用的是高3.2和1.5茉莉

I'm using ko 3.2 and jasmine 1.5

推荐答案

您没有明确应用您绑定到一个节点。我相信，因此该会应用到您的 document.body的。这也解释了你的错误作为你不是清洁身体。

Your not explicitly applying your bindings to a node. I believe this will therefore apply to your document.body. Which explains your error as your not cleaning the body.

ko.applyBindings（testSubject）;

参考：

如果你想知道什么样的参数ko.applyBindings做，

第一个参数所说的查看您想使用的模型对象
  声明绑定它激活

The first parameter says what view model object you want to use with the declarative bindings it activates

或者，你可以传递第二个参数来定义的哪个部分
  你要搜索的数据绑定属性的文件。例如，
  ko.applyBindings（myViewModel，
  的document.getElementById（'someElementId'））。这会限制
  激活到具有ID someElementId及其后代的元素，
  其中，如果你想有多个视图模型和准是非常有用的
  每个与网页的不同区域

Optionally, you can pass a second parameter to define which part of the document you want to search for data-bind attributes. For example, ko.applyBindings(myViewModel, document.getElementById('someElementId')). This restricts the activation to the element with ID someElementId and its descendants, which is useful if you want to have multiple view models and associate each with a different region of the page.

有用的功能：

// Checks if Element has Already been Bound (Stops Errors Occuring if already bound as element can't be bound multiple times)
var isBound = function (id) {
    if (document.getElementById(id) != null)
        return !!ko.dataFor(document.getElementById(id));
    else
        return false;
};

答：

testSubject = new Mobile.Navigation.ThreeStepNavigation.View();
if (isBound("parent-container"))
    ko.cleanNode(document.getElementById('parent-container'));
ko.applyBindings(testSubject, document.getElementById("parent-container"));

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