Switch from es6-shim to core-js/client/shim #851

tl;dr

The es6-shim is fatally slow for IE10 and IE11. The alternative core-js/client/shim.min.js can be as much as 25x faster.

Switch to that library when generating the ES6 shim script for index.html:

// package.json: "core-js": "^2.4.0",

<script src="node_modules/client/shim.min.js"></script>

Background

We (IdeaBlade) have a large A2 app that can display 1000s of table rows. Works fine in Chrome, Edge, FF. Died miserably in IE11 and IE10.

Discovered that core-js is ​25x faster than the es6-shim library when processing arrays of data. The app is now usable on IE11 (IE10 testing pending).

See https://www.npmjs.com/package/core-js
See also: http://stackoverflow.com/questions/36570532/angular-2-performance-ie11-ngfor

After discussion with @mhevery and PatrickJS, have decided to switch to core-js. Core-js is highly modular and one could build a custom bundle.

We want one file that covers the largest shimming needs and don't want to have to maintain our own fine-tuned bundle. We selected the core-js/client/shim.min.js (77k) as best fit for our needs.

Am in process of migrating all doc samples to use this core-js shim.

Verification:

IdeaBlade reports success on IE11, Chrome, Edge, and FF with this library.

Ward spot checked a few of the larger doc samples in IE11 as well as Chrome and Edge.

No known tests on IE10 or Safari yet.