Mocha Mocking Js 实例函数

Question

使用 Mocha、Jsdom、enzyme 和 Expect 断言。

canPlayType总是returns一个空字符串因为我不是运行浏览器中的测试。处理这个问题的最佳方法是什么？我会嘲笑它吗？如果是，我会如何嘲笑它？

规格文件：

it('should be able to play media',() => {
    expect(canPlayMedia()).toBe(true);
});

js文件：

const canPlayMedia = () => {
    const mediaElement = document.createElement('audio');
    // canPlayType is always empty string
    const canPlay = mediaElement.canPlayType('audio/mpeg');

    return canPlay;
}

jsdom 文件：

// setup the simplest document possible
const doc = jsdom.jsdom('<!doctype html><html><body></body></html>');

// get the window object out of the document
const win = doc.defaultView;

// set globals for mocha that make access to document and window feel
// natural in the test environment
global.document = doc;
global.window = win;

// from mocha-jsdom https://github.com/rstacruz/mocha-jsdom/blob/master/index.js#L80
const propagateToGlobal = (window) => {
  Object.keys(window).forEach((key) => {
    if (Object.prototype.hasOwnProperty.call(window, key) && !(key in global)) {
      global[key] = window[key];
    }
  });
};

global.document.webkitExitFullscreen = () => null;

// take all properties of the window object and also attach it to the
// mocha global object
propagateToGlobal(win);

Answer 1

it('should be able to play audio',() => {
    const audio = document.createElement('audio');

    expect.spyOn(document, 'createElement').andReturn(audio);
    expect.spyOn(audio, 'canPlayType').andReturn(true);

    expect(canPlayMedia()).toBe(true);

    document.createElement.restore();
});

Mocha Mocking Js 实例函数

Mocha Mocking Js instance functions

javascript

mocha.js

jsdom

reactjs

enzyme