node.js - Is there a way to isolate native-object extensions in javascript? -

you can extend native objects in javascript. example, sugar.js extends array, string, , function among other things. native-object extensions can useful, inherently break encapsulation - ie if uses same extension name (overwriting extension) things break.

it incredibly nice if extend objects particular scope. e.g. being able in node.js:

// myextension1.js object.prototype.x = 5  exports.speak = function() {   var 6 = ({}.x+1)   console.log("6 equals: "+six) }  // myextension2.js object.prototype.x = 20  exports.speak = function() {   var twenty1 = ({}.x+1)   console.log("21 equals: "+twenty1) } 

and have work right:

// test.js  var 1 = require('myextension1') var 2 = require('myextension2')  one.speak(); // 6 equals: 6 two.speak(); // 21 equals: 21 

of course in reality, print out "6 equals: 21" first one.

is there way, via mechanism, possible? mechanisms i'm interesting in hearing include:

• pure javascript
• node.js
• c++ extensions node.js

unfortunately cannot in node, because node shares same built-in objects across modules.

this bad because brings unexpected side effects, happened in browsers history in past, , that's why yelling "don't extend built-in object".

other commonjs environment following more original commonjs specs, not share built-in object, every module has own. instance in jetpack, mozilla sdk build firefox's add-on, works in way: built-in objects per module , if extend 1 can't clash.

anyway, in general believe extending built-in object nowadays not necessary , should avoided.