sp-jsom
This project provides support for JSOM.
In order to use it, write require('@microsoft/sp-jsom'); in the code.
This will load JSOM and it will be ready to use throughout the code.
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.