unitTestSetup.ts

import { JSDOM } from "jsdom";

interface Global extends NodeJS.Global {
  window: Window;
  document: Document;
  navigator: {
    userAgent: string;
  };
}

const globalNode: Global = {
  window: window,
  document: window.document,
  navigator: {
    userAgent: "node.js"
  },
  ...global
};

// Simulate window for Node.js
if (!globalNode.window && !globalNode.document) {
  const { window } = new JSDOM("<!doctype html><html><body></body></html>", {
    beforeParse(win) {
      win.scrollTo = () => {};
    },
    pretendToBeVisual: false,
    userAgent: "mocha"
  });

  // Configure global variables which like to be used in testing
  globalNode.window = window;
  globalNode.document = window.document;
  globalNode.navigator = window.navigator;
}

import * as enzyme from "enzyme";
import Adapter from "enzyme-adapter-react-16";
const adapter = new Adapter();
enzyme.configure({ adapter });