CodePad Mocha Examples (Try them on https://codepad.remoteinterview.io/)

basic.js

// from https://gist.github.com/kmoroder/174cc7074ff099256620c7605bdb3368
var foo = function() {
  return "bar";
}

var Mocha = require('mocha');
var expect = require('chai').expect;
var mocha = new Mocha({ui: 'bdd'});
mocha.suite.emit('pre-require', this, 'solution', mocha);

describe("Test suite", function () {
  it("is working", function () {
    expect(foo()).to.equal("bar");
  });
});

mocha.run(function() {});

withJSDom.js

const jsdom = require("jsdom");
const { JSDOM } = jsdom;
const Mocha = require('mocha');
const assert = require('assert');
const mocha = new Mocha();

function getContentByClassName(className) {
  const elements = document.getElementsByClassName(className);
  if (elements.length === 0) {
    return '';
  }

  return elements[0].textContent;
}

const dom = new JSDOM(`<div class="foo">my content</div>`);

const window = dom.window;
const document = dom.window.document;

mocha.suite.emit('pre-require', this, 'solution', mocha);

describe('#getContentByClassName', () => {
  it('should return an empty string if given a non existent class', () => {
    assert(getContentByClassName('bar') === '');
  });

  it('should return the content of a class', () => {
    assert(getContentByClassName('foo') === 'my content');
  });
});

mocha.run();