sp-polyfills
A "polyfill" is a script that emulates a modern JavaScript feature when it is not available in an older web browser.
The sp-polyfills package provides standard polyfills for the specific feature set that the SharePoint Framework
expects from its environment. It is acceptable for a browser environment (e.g. a unit test runner) to load its own
polyfills, but they must be equivalent to the definitions in this package.
This package is part of the SharePoint Framework,
which is a collection of NPM packages that empower developers to create client-side experiences
for Microsoft SharePoint.
For more information, including complete API documentation and code samples, please visit
the SharePoint Framework web site.