Promise not defined in IE 11

• Laravel Mix Version: 0.8.1
• Node Version (node -v): 6.9.2
• NPM Version (npm -v): 412
• OS: Mac OS

Description:

Getting Promise is not defined in IE 11. Does babel not convert this by default? Where do i add the needed config to polyfill Promise?

[scottgrayson]

Babel polyfill fixed it. I’m not using Promise myself, but its one of the packages i am importing. Mix should run on all those too right?

npm install --save babel-polyfill then in bootstrap.js //or some main js file import 'babel-polyfill'

[adiachenko]

Yes, you can simply include babel-polyfill, but unless you’re building SPA and you don’t care about the bloat of the size of another framework in your bundle, you should probably not. It’s better to require the stuff you need by hand.

It may be reasonable though to provide promise polyfill and, maybe, object-assign, out of the box. For example, this is the snippet from CRA that achieves this exact thing:

if (typeof Promise === 'undefined') {
  require('promise/lib/rejection-tracking').enable();
  window.Promise = require('promise/lib/es6-extensions.js');
}

Object.assign = require('object-assign')

This example is particularly good, because it enables rejection tracking.

UPD: In short, I don’t think encouraging the use of babel-polyfill is a great idea. But if you think that informing people on it would be too much of a pain, it’s desirable to at least include babel-polyfill from within webpack.mix.js, so that developers can easily disable implicit behavior and fall back to a more granular approach.