Error: It looks like you called `mount()` without a global document being loaded

Question

我正在尝试安装一个组件以使用酶进行测试，但出现此错误。

Answer 1

Mocha 没有运行你在浏览器环境下的测试，所以没有DOM。要解决此问题，只需使用 jsdom npm 模块创建一个 DOM.

Since enzyme's mount API requires a DOM, JSDOM is required in order to use mount if you are not already in a browser environment (ie, a Node environment).

JSDOM is a JavaScript based headless browser that can be used to create a realistic testing environment.

For the best experience with enzyme, it is recommended that you load a document into the global scope before requiring React for the first time. It is very important that the below script gets run before React's code is run.

As a result, a standalone script like the one below is generally a good approach:

/* setup.js */

var jsdom = require('jsdom').jsdom;

var exposedProperties = ['window', 'navigator', 'document'];

global.document = jsdom('');
global.window = document.defaultView;
Object.keys(document.defaultView).forEach((property) => {
  if (typeof global[property] === 'undefined') {
    exposedProperties.push(property);
    global[property] = document.defaultView[property];
  }
});

global.navigator = {
  userAgent: 'node.js'
};

阅读Enzyme documentation - JSDOM了解更多信息

Answer 2

npm install --save-dev --save-exact jsdom jsdom-global

然后：

import 'jsdom-global/register'; //at the top of file, even before importing React

更多信息here。

备选方案：如果您使用的是 jest with enzyme-

在你的package.json中指定jest的测试环境为jsdom如下：

"jest": {
  "testEnvironment": "jsdom"
}

我遇到了同样的问题，它对我来说效果很好。

Answer 3

只需将以下内容放在测试文件的顶部

/**
 * @jest-environment jsdom
*/

Error: It looks like you called `mount()` without a global document being loaded

Error: It looks like you called `mount()` without a global document being loaded

reactjs

enzyme