Opinion about global wrappers in nodejs

global.js

//global variable 
test = 'hello';

//is exactly the same as
global.test = 'hello';

//local variable - this will definitly override your global variable
var test = 'hello';

//using the process scope, if, and really if, you can't do without a global variable
process.test = 'world';

//Now both will be defined and using `process` will avoid any confusion
console.log(test + process.test);
//hello world

Also, some modules are defining global variables and could be a headache when you define a variable and everything breaks.
For example, the famous colors package is extending String.

Global variables could become handy to store configuration objects so that you won't have to require it on each page.

The worst I've seen is the shelljs module.
If you use the global version you'll require this file.
Assuming you did:

global.config = {my: 'awesome', config: 'object'}
require('shelljs/global')
//no more configuration and hours of debugging

Why the heck?
The global.js file will export each key of the main file and L131 states:

//@
//@ ## Configuration
//@

exports.config = common.config;

... BOOM 😑