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

Question

I\'m trying to mount a component for testing with enzyme, and get this error.

Answer 1

Mocha doesn't run your test in a browser environment,so there is no DOM. To fix this problem, simply you have to use jsdom npm module to create a DOM.

From Enzyme docs :

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'
};

Read Enzyme documentation - JSDOM for more informations