with-global

Run code that depends on presence of a global variable without permanent pollution of the global namespace.

Useful with browserify/webpack.

Example

Say you have an old jquery plugin that never heard of UMD and wants the $ global, but you don't want to override window.$ (maybe some other code depends on another version of jquery).

Solution:

1. Set required globals
2. Evaluate the nasty script
3. Restore old globals

const $ = require('jquery');
const withGlobals = require('with-globals');
 
withGlobals({
    $,
    jQuery: $,
}, function () {
    // window.$ and window.jQuery now have the desired value
    require('jquery.nastyplugin');
});
 
// window.$ and window.jQuery were restored to their previous value

Note that there is still one thing the nasty module has to do right: that is to capture the values of necessary globals like this (function ($) { ... })($); Most of the time they do do this.