jsoneditor/test/setup.js

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

/**
 * Set up the test environment by simulating browser globals.
 * @param {string} [locale=en] A locale to set in navigator.language
 * @return {void}
 */
module.exports = function setUpTestEnvironment(locale) {
    if (!locale) {
        locale = 'en'
    }

    var dom = new JSDOM('...');
    global.window = dom.window;
    global.document = dom.window.document;
    global.navigator = dom.window.navigator;

    // JSDom has no setter defined for navigator.language, so defineProperty is necessary in order to override it
    Object.defineProperty(navigator, 'language', {value: locale})
};