JavaScript Environment Requirements

React 16 depends on the collection types Map and Set. If you support older browsers and devices which may not yet provide these natively (e.g. IE < 11) or which have non-compliant implementations (e.g. IE 11), consider including a global polyfill in your bundled application, such as core-js.

A polyfilled environment for React 16 using core-js to support older browsers might look like:

import "core-js/es/map";
import "core-js/es/set";

import React from "react";
import ReactDOM from "react-dom";

ReactDOM.render(<h1>Hello, world!</h1>, document.getElementById("root"));

React also depends on requestAnimationFrame (even in test environments). You can use the raf package to shim requestAnimationFrame:

import "raf/polyfill";