EvanHahn / untouched

get pristine copies of built-in objects (like Array or JSON) even if they've been modified

untouched

Get pristine copies of built-in objects (like Array or JSON), even if they've been modified. This is generally for library authors who find themselves in monkey-patched browser environments.

Currently only made for browsers. Feel free to submit a patch!

Usage:

const untouched = require("untouched");

const myUntouched = untouched();
const untouchedJson = myUntouched("JSON");

You can also include the script tag on the page (grab it from src/untouched.js):

<script src="untouched.js"></script>
<script>
  const myUntouched = untouched();
  const untouchedJson = myUntouched("JSON");
</script>

Here's an example:

// Let's say that someone has messed with the Array prototype.
// If you try to use it, you're screwed!
Array.prototype.map = () => "this no longer works";

// This will return 'this no longer works'!
const arr = [1, 2, 3];
arr.map(() => n * n);

// With untouched, you can get around this problem.
// This returns what you expect!
const myUntouched = untouched();
const untouchedArr = new myUntouched("Array")(1, 2, 3);
untouchedArr.map(() => n * n);

// You can use it for things other than Array, too.
const untouchedJson = myUntouched("JSON");
untouchedJson.stringify({ hi: 5 });

We accomplish this by creating a hidden <iframe> and pulling variables out of it. You can remove the iframe whenever you're done with it:

myUntouched.destroy();