Fetch polyfill in React not completely working in IE 11

Question

This fetch works fine in Chrome:

fetch( this.props.url, {credentials:\'same-origin\'})
    .then( (data) => data.js         


        

Answer 1

Looking at isomorphic-fetch, the package is just a meta-package of sorts that import-exports either whatwg-fetch or node-fetch depending on whether you are in a browser or Node context.

I think your issue is that it will use the node version by default (see the main entry in the package.json).

Being a polyfill, it is simply skipped on non-IE as the browsers support fetch by default. On IE11 the polyfill is used, but it's the Node polyfill which won't work in a browser.

You might be able to coerce webpack to use the browser version by including the browser specific version:

require('isomorphic-fetch/fetch-npm-browserify')

or

import 'isomorphic-fetch/fetch-npm-browserify'

or in Webpack config:

entry: [
    'isomorphic-fetch/fetch-npm-browserify',
    'app.js'
]