CoreJS to shim or not to shim

Question

I'm using https://github.com/zloirock/core-js as an ES6 polyfill for TypeScript 1.5.0 I got from npm

I'm curious what's the difference between:

 // Default
 require('core-js');

And:

 // Shim only
 require('core-js/shim');

Another question, what are the other alternatives for ES6 polyfill?

Answer 1

The shim.js polyfills all standard ECMAScript methods. The index.js polyfills non-standard methods in addition.

See the required sub modules in the source code:

• index.js (these are not standard)
• shim.js (these are standard)