ES6 `fetch is undefined`

You need to add the 'isomorphic-fetch' module to your 'package.json' and then import this.

npm install --save isomorphic-fetch es6-promise

Then in your code

import "isomorphic-fetch"

See https://www.npmjs.com/package/isomorphic-fetch

I will use the two following cdn like this:

<script src="//cdn.jsdelivr.net/bluebird/3.5.0/bluebird.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fetch/2.0.3/fetch.js"></script>