防止Jasmine测试expect()在JS完成执行之前解决

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我希望你能提供帮助。我对单元测试很新。我有一个运行PhantomJS浏览器的Karma + Jasmine设置。这一切都很好。

我正在努力的是我在页面上有一个链接,当点击此链接时,它会注入一些html。我想测试HTML是否已注入。

现在,在这一点上,我有测试工作,但有时只有我可以弄清楚,如果我的JS运行得足够快,在expect()运行之前注入HTML。如果不是,则测试失败。

expect()运行之前,如何让我的Jasmine测试等待所有JS完成执行?

有问题的测试是it("link can be clicked to open a modal", function() {

modal.spec.js

const modalTemplate = require('./modal.hbs');

import 'regenerator-runtime/runtime';
import 'core-js/features/array/from';
import 'core-js/features/array/for-each';
import 'core-js/features/object/assign';
import 'core-js/features/promise';

import Modal from './modal';

describe("A modal", function() {

    beforeAll(function() {
        const data = {"modal": {"modalLink": {"class": "", "modalId": "modal_1", "text": "Open modal"}, "modalSettings": {"id": "", "modifierClass": "", "titleId": "", "titleText": "Modal Title", "closeButton": true, "mobileDraggable": true}}};
        const modal = modalTemplate(data);
        document.body.insertAdjacentHTML( 'beforeend', modal );
    });

    it("link exists on the page", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        expect(modalLink).not.toBeNull();
    });

    it("is initialised", function() {
        spyOn(Modal, 'init').and.callThrough();
        Modal.init();

        expect(Modal.init).toHaveBeenCalled();
    });

    it("link can be clicked to open a modal", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        modalLink.click();

        const modal = document.body.querySelector('.modal');
        expect(modal).not.toBeNull();
    });

    afterAll(function() {

        console.log(document.body);

        // TODO: Remove HTML

    });

});

编辑 - 更多信息

为了进一步阐述这一点,我认为,评论中的Jasmine 2.0 how to wait real time before running an expectation链接有助于我更好地理解。所以我们说它我们想要spyOn函数并等待它被调用然后启动一个回调然后解决测试。

大。

我的下一个问题是,如果你看看下面我的ModalViewModel类的结构,我需要能够spyOn insertModal()能够做到这一点,但是init()唯一可以访问的功能。我能做些什么来推进这种方法?

import feature from 'feature-js';
import { addClass, removeClass, hasClass } from '../../01-principles/utils/classModifiers';
import makeDraggableItem from '../../01-principles/utils/makeDraggableItem';
import '../../01-principles/utils/polyfil.nodeList.forEach'; // lt IE 12

const defaultOptions = {
    id: '',
    modifierClass: '',
    titleId: '',
    titleText: 'Modal Title',
    closeButton: true,
    mobileDraggable: true,
};

export default class ModalViewModel {
    constructor(module, settings = defaultOptions) {
        this.options = Object.assign({}, defaultOptions, settings);
        this.hookModalLink(module);

    }

    hookModalLink(module) {
        module.addEventListener('click', (e) => {
            e.preventDefault();


            this.populateModalOptions(e);
            this.createModal(this.options);
            this.insertModal();

            if (this.options.closeButton) {
                this.hookCloseButton();
            }

            if (this.options.mobileDraggable && feature.touch) {
                this.hookDraggableArea();
            }

            addClass(document.body, 'modal--active');

        }, this);
    }

    populateModalOptions(e) {
        this.options.id = e.target.getAttribute('data-modal');
        this.options.titleId = `${this.options.id}_title`;
    }

    createModal(options) {
        // Note: As of ARIA 1.1 it is no longer correct to use aria-hidden when aria-modal is used
        this.modalTemplate = `<section id="${options.id}" class="modal ${options.modifierClass}" role="dialog" aria-modal="true" aria-labelledby="${options.titleId}" draggable="true">
                                ${options.closeButton ? '<a href="#" class="modal__close icon--cross" aria-label="Close" ></a>' : ''}
                                ${options.mobileDraggable ? '<a href="#" class="modal__mobile-draggable" ></a>' : ''}
                                <div class="modal__content">
                                    <div class="row">
                                        <div class="columns small-12">
                                            <h2 class="modal__title" id="${options.titleId}">${options.titleText}</h2>
                                        </div>
                                    </div>
                                </div>
                            </section>`;

        this.modal = document.createElement('div');
        addClass(this.modal, 'modal__container');
        this.modal.innerHTML = this.modalTemplate;
    }

    insertModal() {
        document.body.appendChild(this.modal);
    }

    hookCloseButton() {
        this.closeButton = this.modal.querySelector('.modal__close');

        this.closeButton.addEventListener('click', (e) => {
            e.preventDefault();
            this.removeModal();
            removeClass(document.body, 'modal--active');
        });
    }

    hookDraggableArea() {
        this.draggableSettings = {
            canMoveLeft: false,
            canMoveRight: false,
            moveableElement: this.modal.firstChild,
        };

        makeDraggableItem(this.modal, this.draggableSettings, (touchDetail) => {
            this.handleTouch(touchDetail);
        }, this);
    }

    handleTouch(touchDetail) {
        this.touchDetail = touchDetail;
        const offset = this.touchDetail.moveableElement.offsetTop;

        if (this.touchDetail.type === 'tap') {
            if (hasClass(this.touchDetail.eventObject.target, 'modal__mobile-draggable')) {

                if (offset === this.touchDetail.originY) {
                    this.touchDetail.moveableElement.style.top = '0px';
                } else {
                    this.touchDetail.moveableElement.style.top = `${this.touchDetail.originY}px`;
                }

            } else if (offset > this.touchDetail.originY) {
                this.touchDetail.moveableElement.style.top = `${this.touchDetail.originY}px`;
            } else {
                this.touchDetail.eventObject.target.click();
            }
        } else if (this.touchDetail.type === 'flick' || (this.touchDetail.type === 'drag' && this.touchDetail.distY > 200)) {

            if (this.touchDetail.direction === 'up') {

                if (offset < this.touchDetail.originY) {
                    this.touchDetail.moveableElement.style.top = '0px';
                } else if (offset > this.touchDetail.originY) {
                    this.touchDetail.moveableElement.style.top = `${this.touchDetail.originY}px`;
                }

            } else if (this.touchDetail.direction === 'down') {

                if (offset < this.touchDetail.originY) {
                    this.touchDetail.moveableElement.style.top = `${this.touchDetail.originY}px`;
                } else if (offset > this.touchDetail.originY) {
                    this.touchDetail.moveableElement.style.top = '95%';
                }

            }
        } else {
            this.touchDetail.moveableElement.style.top = `${this.touchDetail.moveableElementStartY}px`;
        }
    }

    removeModal() {
        document.body.removeChild(this.modal);
    }

    static init() {
        const instances = document.querySelectorAll('[data-module="modal"]');

        instances.forEach((module) => {
            const settings = JSON.parse(module.getAttribute('data-modal-settings')) || {};
            new ModalViewModel(module, settings);
        });
    }
}

UPDATE

经过研究发现,.click()事件是异步的,这就是我遇到种族问题的原因。 Web上推荐使用createEvent()dispatchEvent()的文档和Stack Overflow问题,因为PhantomJs不了解new MouseEvent()

这是我的代码,现在正试图这样做。

modal.spec.js

// All my imports and other stuff
// ...

function click(element){
    var event = document.createEvent('MouseEvent');
    event.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    element.dispatchEvent(event);
}

describe("A modal", function() {

    // Some other tests
    // Some other tests

    it("link can be clicked to open a modal", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        click(modalLink);

        const modal = document.body.querySelector('.modal');
        expect(modal).not.toBeNull();
    });

    // After all code
    // ...

});

不幸的是,这产生了相同的结果。靠近一步,但不是那么近。

答案

经过一番研究后,看起来你对click事件的使用触发了一个异步事件循环,主要是说“嘿设置这个东西被点击然后激活所有处理程序”

您当前的代码无法看到它并且没有真正的等待方式。我相信您应该能够使用此处的信息构建和发送鼠标单击事件。 https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/dispatchEvent

我认为应该允许你构建一个click事件并将它发送到你的元素上。不同之处在于dispatchEvent是同步的 - 它应该阻止你的测试,直到点击处理程序完成。这应该允许您在没有失败或竞争条件的情况下进行断言。

另一答案

我终于找到了解决方案。

这有两个部分,第一部分来自@CodyKnapp。他对异步运行的click()函数的见解有助于解决问题的第一部分。

这是这部分的代码。

modal.spec.js

// All my imports and other stuff
// ...

function click(element){
    var event = document.createEvent('MouseEvent');
    event.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    element.dispatchEvent(event);
}

describe("A modal", function() {

    // Some other tests
    // Some other tests

    it("link can be clicked to open a modal", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        click(modalLink);

        const modal = document.body.querySelector('.modal');
        expect(modal).not.toBeNull();
    });

    // After all code
    // ...


});

这允许代码同步运行。

第二部分是我对如何编写Jasmine测试的不了解。在我最初的测试中,我在Modal.init()内部运行it("is initialised", function() {,而实际上我想在beforeAll()中运行它。这解决了我的测试并不总是成功的问题。

这是我的最终代码:

modal.spec.js

const modalTemplate = require('./modal.hbs');

import '@babel/polyfill';

import Modal from './modal';

function click(element){
    var event = document.createEvent('MouseEvent');
    event.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    element.dispatchEvent(event);
}

describe("A modal", function() {

    beforeAll(function() {
        const data = {"modal": {"modalLink": {"class": "", "modalId": "modal_1", "text": "Open modal"}, "modalSettings": {"id": "", "modifierClass": "", "titleId": "", "titleText": "Modal Title", "closeButton": true, "mobileDraggable": true}}};
        const modal = modalTemplate(data);
        document.body.insertAdjacentHTML( 'beforeend', modal );

        spyOn(Modal, 'init').and.callThrough();
        Modal.init();
    });

    it("link exists on the page", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        expect(modalLink).not.toBeNull();
    });

    it("is initialised", function() {
        expect(Modal.init).toHaveBeenCalled();
    });

    it("link can be clicked to open a modal", function() {
        const modalLink = document.body.querySelector('[data-module="modal"]');
        click(modalLink);

        const modal = document.body.querySelector('.modal');
        expect(modal).not.toBeNull();
    });

    afterAll(function() {

        console.log(document.body);

        // TODO: Remove HTML

    });

});

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