Package Exports
- default-require-extensions
- default-require-extensions/js
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (default-require-extensions) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
default-require-extensions 
Node's default require extensions as a separate module
Handy for require extension authors that want reliable access to the default extension implementations.
By the time your extension is loaded, the default extension may have already been replaced. This provides extensions functionally identical to the default ones, which you know you can access reliably, no matter what extensions have been installed previously.
Install
$ npm install default-require-extensions
Usage
const js = require('default-require-extensions/js');
const json = require('default-require-extensions/json');
require.extensions['.js'] = js;
require.extensions['.js'] = json;
Note: You would never actually do the above. Use these in your custom require extensions instead.