How can I polyfill Promise with webpack?

Question

I'm using webpack to bundle up my JavaScript. I'm depending on modules like popsicle which use any-promise.

Here's my code:

var popsicle = require('popsicle');
popsicle.get('/').then(function() {
  console.log('loaded URL');
});

This works fine in browsers where Promise is available, but IE 11 does not provide Promise. So I want to use es6-promise as a polyfill.

I tried adding an explicit ProvidePlugin to my webpack.config.js:

plugins: [
  new webpack.ProvidePlugin({
    'Promise': 'exports?global.Promise!es6-promise'
  })
]

But I still get the error in IE 11: any-promise browser requires a polyfill or explicit registration e.g: require('any-promise/register/bluebird').

I tried explicitly attaching a global:

global.Promise = global.Promise || require('es6-promise');

But IE 11 gives a different error: Object doesn't support this action.

I also tried explicitly registering es6-promise:

require('any-promise/register/es6-promise');
var popsicle = require('popsicle');

This works, but I have to do it in every single file that loads popsicle. I want to just attach Promise to window.

How can I ensure window.Promise is always defined, using webpack?

Full repo demo here.

Answer 1

For people using babel in combination with webpack: you can use babel-polyfill

Just do npm install --save "babel-polyfill" and then add it as an entry point in your webpack.config.js:

module.exports = {
   entry: ['babel-polyfill', './app/js']
};

Or, instead of using the entire babel-polyfill you can install core-js and reference only the module you need.

module.exports = {
   entry: ['core-js/stable/promise', './app/js']
};