[feature-request] Object.keys should coerce primitive values in IE11

[neenhouse]

Overview

In IE11, running the following causes a uncontrolled exception to occur:

Object.keys(50);

This is problematic for applications written with modern JS, babel is typically used to allow statements like:

const myData = {...dataA, ...dataB}

Babel will transpile that line and implement a function called _objectSpread: https://github.com/babel/babel/blob/a112be2fa0b2abab7fd9a845b3a76b273c506449/packages/babel-helpers/src/helpers.js#L393, which implements Object.keys:

...
var ownKeys = Object.keys(source);
...

This is a highly traveled path in UI apps that implement object spread syntax (which is pretty common these days). Spreading non object type data is a pretty easy mistake to make, and modern browsers forgive.

To prevent exception in IE11 with string and number, we should use the polyfill provided from this lib which already follows the ECMA-262 ed 6 spec (http://ecma-international.org/ecma-262/6.0/index.html#sec-object.keys).

Why does this matter

Companies who are trying to optimize their polyfill payload can very likely run into this issue when they try to swap out core-js Object APIs for polyfill-library with apps that implement object spread. This issue can cause complete failure in apps and prevent adoption of polyfill-library.

Browsers impacted

• IE11
• Others?

I should be able to prepare a PR pretty soon to address this issue.