```
addMethod.js

function add(){
  // do something
}

```

Let say, I have a function `add` which can be accessed globally. But when I bundled this file with webpack(v4) I am facing an error `add of undefined` when I ran that file in the browser.

So far in my research, I have only come across people recommending that **global functions and methods must be appended to window object** 

The problem is in a larger project, how do I handle these kinds of problems?

I know I can use `export or window` keyword.

But I am looking for any webpack plugin that will take care of this, instead of me having to update every file in my project??

**Note: Webpack version - 4 and `ES5`**